NBDHE Exam — Questions and Answers

Question 1: Documentation in the dental hygiene record should follow which standard to ensure medicolegal protection?

Entries should be timely, accurate, objective, complete, legible, and corrected properly (single line through errors with initials and date) (Correct answer)
Records can be altered retroactively if needed for insurance processing
Errors should be completely erased and rewritten correctly
Dental hygienists should document only procedures, not patient behaviors or statements

Correct answer: Entries should be timely, accurate, objective, complete, legible, and corrected properly (single line through errors with initials and date)

Proper clinical documentation must be timely (recorded during/immediately after treatment), accurate, objective, complete, signed, and corrected with a single line through errors — never erased, whited-out, or altered retroactively.

Question 2: Which foramen transmits the mental nerve and vessels?

Mental foramen (Correct answer)
Incisive foramen
Mandibular foramen
Infraorbital foramen

Correct answer: Mental foramen

The mental foramen, located on the lateral surface of the mandible below the premolars, transmits the mental nerve and vessels.

Question 3: According to the American Academy of Pediatric Dentistry, a child's first dental visit should occur:

At age 2 years
At age 3 years
By age 1 or within 6 months of the first tooth erupting (Correct answer)
When all primary teeth have erupted

Correct answer: By age 1 or within 6 months of the first tooth erupting

The AAPD recommends the first dental visit by age 1 or within 6 months of the first primary tooth erupting to establish early preventive care.

Question 4: A patient presents with a painful swelling on the floor of the mouth, inferior to the tongue, which worsens just before and during meals. A blockage of which structure is the MOST likely cause of these symptoms?

Wharton's duct (Correct answer)
Stensen's duct
Ducts of Rivinus
Bartholin's duct

Correct answer: Wharton's duct

Wharton's duct is the main excretory duct for the submandibular salivary gland. A blockage, often by a sialolith (salivary stone), causes saliva to back up, leading to painful swelling in the floor of the mouth that is exacerbated by the increased saliva production associated with eating. Stensen's duct serves the parotid gland, while Bartholin's and Rivinus ducts serve the sublingual gland.

Question 5: Tertiary prevention in dental hygiene practice focuses on:

Early detection of disease before symptoms appear
Restoring function and preventing further disability after disease (Correct answer)
Preventing disease from occurring in healthy patients
Providing nutritional counseling to at-risk patients

Correct answer: Restoring function and preventing further disability after disease

Tertiary prevention aims to restore function and minimize disability after disease has occurred, such as prosthetic rehabilitation following tooth loss from periodontitis.

Question 6: Which of the following appears radiopaque on a dental radiograph?

Periodontal ligament space
Amalgam restoration (Correct answer)
Pulp chamber
Periapical cyst

Correct answer: Amalgam restoration

Amalgam is a high-density metal alloy that absorbs X-rays and appears as a bright white (radiopaque) area on radiographs.

Question 7: When using alginate impression material, what is the effect of using warmer water during mixing?

Decreases setting time (Correct answer)
Increases flexibility of the set impression
Decreases tear strength
Increases working time

Correct answer: Decreases setting time

Warmer water accelerates the chemical reaction in alginate, decreasing the setting time and reducing the working time available to the clinician.

Question 8: Which type of bone defect has the best prognosis for regeneration with guided tissue regeneration (GTR)?

Horizontal bone loss
Class III furcation involvement
Three-wall vertical (intrabony) defect (Correct answer)
One-wall vertical defect

Correct answer: Three-wall vertical (intrabony) defect

Three-wall intrabony defects have the best regenerative prognosis because three bony walls provide support and blood supply for the regenerative membrane.

Question 9: What is the FIRST recommended action following a needlestick or sharps injury in dental practice?

Apply an antiseptic or iodine solution to the wound
Report the incident immediately to the supervisor
Apply pressure with sterile gauze to stop bleeding first
Wash the wound thoroughly with soap and water (Correct answer)

Correct answer: Wash the wound thoroughly with soap and water

The CDC recommends immediately washing needlestick injuries with soap and water as the first step in post-exposure management.

Question 10: What does the term 'clinical attachment level' (CAL) measure?

Distance from the alveolar crest to the base of the pocket
Distance from the gingival margin to the base of the sulcus
Distance from the mucogingival junction to the gingival margin
Distance from the CEJ to the base of the periodontal pocket (Correct answer)

Correct answer: Distance from the CEJ to the base of the periodontal pocket

CAL is measured from the cementoenamel junction (CEJ) to the base of the periodontal pocket, reflecting true attachment loss.

Question 11: The ethical principle of justice in dental hygiene practice requires:

Providing the same treatment to every patient regardless of individual needs
Only treating patients who can pay for services
Prioritizing care for patients with the best prognosis
Treating all patients fairly and equitably, distributing care based on need rather than ability to pay, and avoiding discrimination (Correct answer)

Correct answer: Treating all patients fairly and equitably, distributing care based on need rather than ability to pay, and avoiding discrimination

Justice requires equitable treatment of all patients regardless of race, ethnicity, income, disability, or other factors, and extends to supporting policies that improve access to oral health care for all populations.

Question 12: A patient has probe readings of 2–3 mm with no bone loss detected radiographically. There is bleeding on probing at 60% of sites. This presentation is consistent with:

Chronic periodontitis — slight
Plaque-induced gingivitis (Correct answer)
Periodontal abscess
Aggressive periodontitis

Correct answer: Plaque-induced gingivitis

Normal probing depths with no bone loss but widespread bleeding on probing indicates gingivitis, which is reversible with improved oral hygiene.

Question 13: A dental hygienist who intentionally touches a patient without consent may be liable for which civil wrong?

Negligence
Breach of contract
Defamation
Battery (Correct answer)

Correct answer: Battery

Battery is the intentional, unconsented touching of another person; performing a procedure without patient consent can constitute battery in civil law.

Question 14: Motivational interviewing in patient education is best described as:

Lecturing patients about poor oral hygiene habits
A collaborative conversation that strengthens patient motivation for behavior change (Correct answer)
Setting strict compliance goals for patients to meet
Demonstrating proper flossing technique on a model

Correct answer: A collaborative conversation that strengthens patient motivation for behavior change

Motivational interviewing is a patient-centered, collaborative counseling style that elicits and strengthens patients' own motivation and commitment to changing behavior.

Question 15: Foreshortening of a tooth image on a periapical radiograph results from:

Too little vertical angulation
Film bending or curvature
Incorrect horizontal angulation
Too much vertical angulation (Correct answer)

Correct answer: Too much vertical angulation

Excessive vertical angulation causes foreshortening because the X-ray beam is directed too steeply, compressing the apparent length of the tooth.

Question 16: Amelogenesis imperfecta primarily affects which tooth structure?

Dentin
Enamel (Correct answer)
Pulp
Cementum

Correct answer: Enamel

Amelogenesis imperfecta is a hereditary defect of enamel formation affecting enamel quantity or quality without systemic disease.

Question 17: Which dental drug is most likely to cause a false-positive result on a urine drug screen for amphetamines?

Phentermine (appetite suppressant)
Codeine
Pseudoephedrine in OTC decongestants (Correct answer)
Epinephrine 1:100,000 in local anesthetic

Correct answer: Pseudoephedrine in OTC decongestants

Pseudoephedrine, a sympathomimetic found in OTC decongestants that patients may take before dental visits, is a known cause of false-positive amphetamine urine screens.

Question 18: Which bone contains the pterygopalatine fossa?

Maxilla and sphenoid (Correct answer)
Zygomatic and sphenoid
Temporal bone
Palatine and maxilla

Correct answer: Maxilla and sphenoid

The pterygopalatine fossa is formed between the posterior surface of the maxilla anteriorly and the pterygoid process of the sphenoid posteriorly.

Question 19: The modified Bass brushing technique is primarily indicated for which patient population?

Edentulous patients with implants
Patients with periodontal disease or those at high risk for gingivitis (Correct answer)
Patients with gingival recession only
Children with primary dentition

Correct answer: Patients with periodontal disease or those at high risk for gingivitis

The modified Bass technique places bristles at a 45-degree angle to the gingival margin to clean the sulcus, making it ideal for patients with periodontal concerns.

Question 20: Which radiographic landmark appears as a radiopaque Y-shaped structure in the maxillary premolar region?

Incisive foramen
Zygomaticotemporal suture
Inverted Y (junction of nasal fossa and maxillary sinus) (Correct answer)
Median palatine suture

Correct answer: Inverted Y (junction of nasal fossa and maxillary sinus)

The inverted Y is formed by the junction of the floor of the nasal fossa and the anterior wall of the maxillary sinus, visible in the maxillary premolar area.

Question 21: A patient taking metformin for type 2 diabetes is scheduled for a procedure requiring IV contrast dye. Why is this dental consideration important?

Metformin causes additive sedation with nitrous oxide
Metformin reduces local anesthetic efficacy
Metformin must be withheld to prevent lactic acidosis if contrast-induced nephrotoxicity occurs (Correct answer)
Metformin increases bleeding time requiring altered antibiotic prophylaxis

Correct answer: Metformin must be withheld to prevent lactic acidosis if contrast-induced nephrotoxicity occurs

Contrast media can cause acute kidney injury; if renal function declines, metformin accumulates and increases the risk of potentially fatal lactic acidosis.

Question 22: What is the recommended daily fluoride intake upper limit (tolerable upper intake) for adults to avoid chronic fluoride toxicity?

10 mg/day (Correct answer)
5 mg/day
20 mg/day
2 mg/day

Correct answer: 10 mg/day

The tolerable upper intake level (UL) for fluoride in adults is 10 mg/day; chronic excess leads to skeletal fluorosis.

Question 23: A 16-year-old patient with bilateral gingival enlargement, delayed eruption of permanent teeth, and radiographic evidence of multiple follicular cysts should be evaluated for:

Papillon-Lefèvre syndrome
Cyclic neutropenia
Cleidocranial dysplasia (dysostosis) (Correct answer)
Down syndrome

Correct answer: Cleidocranial dysplasia (dysostosis)

Cleidocranial dysplasia is characterized by defective clavicles (absent or hypoplastic), supernumerary teeth, delayed tooth eruption, multiple dentigerous cysts, and delayed closure of fontanelles.

Question 24: The chorda tympani nerve carries which functional components?

General somatic sensation from the tongue
Sympathetic fibers to the parotid gland
Motor innervation to the muscles of the tongue
Special sensory taste from the anterior two-thirds of the tongue AND preganglionic parasympathetic secretomotor fibers to the submandibular and sublingual glands (Correct answer)

Correct answer: Special sensory taste from the anterior two-thirds of the tongue AND preganglionic parasympathetic secretomotor fibers to the submandibular and sublingual glands

The chorda tympani (branch of CN VII) carries SVA (special visceral afferent — taste) from the anterior 2/3 of the tongue and GVE (preganglionic parasympathetic) to the submandibular ganglion for secretomotor control of submandibular and sublingual glands.

Question 25: A dental hygienist practicing beyond their legally defined scope of practice may be subject to:

Mandatory additional continuing education only
Only a verbal warning from the supervising dentist
License suspension or revocation by the state dental board (Correct answer)
A civil fine paid directly to the patient

Correct answer: License suspension or revocation by the state dental board

Practicing outside the legally defined scope of practice can result in license suspension, revocation, or other disciplinary action by the state dental board.

Question 26: The biologic width of the periodontium refers to the combined dimension of:

Junctional epithelium and connective tissue attachment above the alveolar crest (approximately 2.04 mm total) (Correct answer)
Attached gingiva and free gingiva
The periodontal ligament space
Probing depth and recession combined

Correct answer: Junctional epithelium and connective tissue attachment above the alveolar crest (approximately 2.04 mm total)

Biologic width (Gargiulo et al. 1961) = junctional epithelium (~0.97 mm) + supracrestal connective tissue attachment (~1.07 mm) ≈ 2.04 mm; restorations must not violate this space.

Question 27: A periapical radiograph showing a well-defined radiolucency with a sclerotic border at the apex of a vital tooth is MOST likely:

Periapical granuloma
Periapical cyst
Periapical abscess
Periapical cemento-osseous dysplasia (early stage) (Correct answer)

Correct answer: Periapical cemento-osseous dysplasia (early stage)

Early-stage cemento-osseous dysplasia around the apices of vital anterior teeth appears as a well-defined radiolucency; vitality testing differentiates it from endodontically involved lesions.

Question 28: Which of the following analgesics achieves its therapeutic effect primarily by acting on the central nervous system to increase the pain threshold, and it lacks significant anti-inflammatory properties?

Naproxen
Aspirin
Ibuprofen
Acetaminophen (Correct answer)

Correct answer: Acetaminophen

Acetaminophen's primary mechanism of action is within the central nervous system, where it is thought to inhibit COX enzymes in the brain, reducing pain and fever. Unlike NSAIDs (ibuprofen, naproxen, aspirin), it has very weak peripheral anti-inflammatory effects. [6, 8, 21, 25, 27]

Question 29: Which mechanism accounts for the thermal expansion mismatch between amalgam restorations and tooth structure that contributes to marginal breakdown over time?

Amalgam expands at a rate 2–3 times greater than enamel under temperature changes, repeatedly stressing the margin (Correct answer)
Amalgam contracts upon cooling, pulling away from tooth structure permanently
Amalgam undergoes only creep deformation, not thermal dimensional change
Amalgam and enamel have identical coefficients of thermal expansion, so no mismatch occurs

Correct answer: Amalgam expands at a rate 2–3 times greater than enamel under temperature changes, repeatedly stressing the margin

Amalgam's coefficient of thermal expansion is approximately 25 ppm/°C, roughly 2–3 times that of enamel (~11 ppm/°C). This mismatch causes cyclical stress at the restoration margin with each temperature fluctuation, gradually fatiguing and widening the marginal seal over years.

Question 30: The temporomandibular joint (TMJ) is classified as which type of joint?

Simple hinge (ginglymoid) joint only
Ball-and-socket (spheroid) joint
Pivot (trochoid) joint
Ginglymoarthrodial joint (combination hinge and gliding) (Correct answer)

Correct answer: Ginglymoarthrodial joint (combination hinge and gliding)

The TMJ is a ginglymoarthrodial joint: it combines a hinge motion (rotation in the lower compartment) with a gliding motion (translation in the upper compartment), made possible by the articular disc dividing the joint space.

Question 31: Which mechanism BEST explains how fluoride reduces enamel susceptibility to acid dissolution by cariogenic bacteria?

Fluoride binds salivary glycoproteins to block acquired pellicle formation on enamel
Fluoride kills Streptococcus mutans directly by disrupting its cell membrane integrity
Fluoride substitutes for hydroxyl ions in hydroxyapatite, forming fluorapatite with a lower critical pH (~4.5) (Correct answer)
Fluoride inhibits salivary amylase, reducing fermentable carbohydrate availability for plaque bacteria

Correct answer: Fluoride substitutes for hydroxyl ions in hydroxyapatite, forming fluorapatite with a lower critical pH (~4.5)

Fluoride substitutes for hydroxyl groups in the hydroxyapatite crystal lattice to form fluorapatite, which has a critical pH of approximately 4.5 compared to 5.5 for hydroxyapatite. This structurally more stable mineral is significantly more resistant to acid attack from bacterial metabolic byproducts.

Question 32: Which type of stroke is used during the assessment phase of ultrasonic debridement to detect calculus?

Heavy lateral pressure strokes perpendicular to the root
Rapid circular strokes in the base of the pocket
Vertical strokes with the tip directed apically at 45°
Light, overlapping exploratory strokes with the tip parallel to the tooth surface (Correct answer)

Correct answer: Light, overlapping exploratory strokes with the tip parallel to the tooth surface

Ultrasonic assessment uses light, overlapping strokes with the side/tip of the instrument kept nearly parallel to the tooth to detect calculus by tactile feedback without excessive thermal/mechanical trauma.

Question 33: When treating a pregnant patient in the third trimester, which positioning concern must be addressed to prevent a medical emergency?

Tilting the patient slightly to the left to avoid supine hypotensive syndrome (Correct answer)
Placing the patient in full Trendelenburg position
Using a head-down tilt to increase cerebral circulation
Keeping the patient fully upright throughout treatment

Correct answer: Tilting the patient slightly to the left to avoid supine hypotensive syndrome

Left lateral displacement relieves pressure of the gravid uterus on the inferior vena cava, preventing supine hypotensive syndrome.

Question 34: What is the recommended width of keratinized gingiva needed to maintain periodontal health around natural teeth?

At least 1 mm of attached gingiva
A minimum of 5 mm of keratinized gingiva
No minimum is required if the patient maintains excellent oral hygiene
At least 2 mm of keratinized gingiva (1 mm attached) (Correct answer)

Correct answer: At least 2 mm of keratinized gingiva (1 mm attached)

Most consensus statements recommend a minimum of 2 mm of keratinized gingiva (with at least 1 mm attached) to withstand masticatory forces and maintain health around natural teeth.

Question 35: A patient with congestive heart failure is taking furosemide (Lasix). Which oral manifestation may result from this diuretic therapy?

Xerostomia due to reduced fluid intake and diuretic effect (Correct answer)
Oral ulcerations
Gingival hyperplasia
Increased calculus formation

Correct answer: Xerostomia due to reduced fluid intake and diuretic effect

Diuretics like furosemide reduce overall body fluid, which can contribute to decreased salivary flow and xerostomia.

Question 36: Which systemic condition is associated with gingival fibromatosis and multiple odontomas?

Addison's disease
Down syndrome
Gardner syndrome (Correct answer)
Von Recklinghausen disease

Correct answer: Gardner syndrome

Gardner syndrome is characterized by colorectal polyposis, osteomas, epidermoid cysts, and multiple odontomas.

Question 37: Elongation of a tooth image on a periapical radiograph is caused by:

Insufficient vertical angulation (Correct answer)
Film/sensor placed too far from the teeth
Excessive vertical angulation
Excessive horizontal angulation

Correct answer: Insufficient vertical angulation

Insufficient (too little) vertical angulation causes elongation because the X-ray beam is directed too flat relative to the tooth.

Question 38: Hairy leukoplakia, associated with Epstein-Barr virus, is most commonly found in patients with which condition?

HIV/AIDS (Correct answer)
Sjögren's syndrome
Type 2 diabetes
Crohn's disease

Correct answer: HIV/AIDS

Hairy leukoplakia is an opportunistic infection caused by EBV that occurs predominantly in immunocompromised individuals, especially those with HIV/AIDS.

Question 39: During the inflammatory process, which chemical mediator causes vasodilation and increased vascular permeability by acting on H1 receptors?

Serotonin
Histamine (Correct answer)
Prostaglandin E2
Bradykinin

Correct answer: Histamine

Histamine, released from mast cells and basophils, binds H1 receptors to cause vasodilation and increase vascular permeability in early acute inflammation.

Question 40: A fluid-filled mucosal swelling on the lower lip caused by trauma to a minor salivary gland duct is called a:

Fibroma
Ranula
Torus
Mucocele (Correct answer)

Correct answer: Mucocele

A mucocele results from mucus accumulation following trauma or obstruction of a minor salivary gland duct, most commonly on the lower lip.

Question 41: Nikolsky's sign, elicited by rubbing normal-appearing mucosa to produce a blister, is positive in which condition?

Pemphigus vulgaris (Correct answer)
Oral lichen planus
Herpetiform ulcers
Aphthous stomatitis

Correct answer: Pemphigus vulgaris

Pemphigus vulgaris involves autoantibodies against desmogleins, causing intraepithelial separation and a positive Nikolsky's sign.

Question 42: What does the acronym 'ADHA Standards of Clinical Dental Hygiene Practice' include as the five components of the dental hygiene process?

History, Examination, Diagnosis, Treatment, and Follow-up
Intake, Assessment, Intervention, Measurement, and Outcomes
Assessment, Dental Hygiene Diagnosis, Planning, Implementation, and Evaluation (Correct answer)
Screening, Treatment, Education, Referral, and Documentation

Correct answer: Assessment, Dental Hygiene Diagnosis, Planning, Implementation, and Evaluation

The ADHA Standards define the five-step dental hygiene process of care: Assessment, Dental Hygiene Diagnosis, Planning, Implementation, and Evaluation — the professional framework for all dental hygiene practice.

Question 43: Which of the following structures passes through the foramen ovale?

CN V2 and middle meningeal artery
Facial nerve and stylomastoid artery
CN V1 and ophthalmic veins
CN V3 and lesser petrosal nerve (Correct answer)

Correct answer: CN V3 and lesser petrosal nerve

The foramen ovale transmits the mandibular nerve (CN V3), the lesser petrosal nerve (parasympathetics to parotid), and accessory meningeal artery.

Question 44: What is the role of eugenol in zinc oxide eugenol (ZOE) cement?

It acts as a chelating agent that reacts with zinc oxide to form zinc eugenolate (Correct answer)
It increases the setting expansion of the cement
It acts as the acid component that reacts with zinc oxide
It lowers the pH to create an acidic environment for bonding

Correct answer: It acts as a chelating agent that reacts with zinc oxide to form zinc eugenolate

Eugenol chelates with zinc oxide to form an amorphous zinc eugenolate matrix that is the primary reaction product giving ZOE its sedative and setting properties.

Question 45: Following scaling and root planing, re-evaluation is typically performed after how many weeks?

2-4 weeks
4-6 weeks (Correct answer)
1-2 weeks
8-12 weeks

Correct answer: 4-6 weeks

Re-evaluation is typically scheduled 4-6 weeks after SRP to allow tissue healing and reassess pocket depths, bleeding, and need for additional treatment.

Question 46: Which muscle of facial expression closes the eye?

Orbicularis oculi (Correct answer)
Corrugator supercilii
Levator palpebrae superioris
Frontalis

Correct answer: Orbicularis oculi

The orbicularis oculi is the sphincter muscle of the eyelid that closes the eye; its palpebral part closes it gently and the orbital part forcefully.

Question 47: The infraorbital nerve is a branch of which division of the trigeminal nerve, and what structures does it innervate?

Ophthalmic division (V1) — innervates the orbit and forehead
Facial nerve (CN VII) — innervates facial expression muscles
Mandibular division (V3) — innervates the lower lip and chin
Maxillary division (V2) — innervates maxillary anterior teeth, buccal gingiva, upper lip, and cheek skin (Correct answer)

Correct answer: Maxillary division (V2) — innervates maxillary anterior teeth, buccal gingiva, upper lip, and cheek skin

The infraorbital nerve is the terminal branch of V2 (maxillary division), exiting the infraorbital foramen to innervate maxillary anterior teeth, buccal gingiva, upper lip, and skin of the cheek.

Question 48: The Bass toothbrushing technique is most effective at removing plaque from:

Occlusal surfaces only
The gingival sulcus and margin (Correct answer)
The dorsal tongue
Interproximal surfaces only

Correct answer: The gingival sulcus and margin

The Bass technique positions bristles at 45 degrees toward the gingival sulcus, making it highly effective at removing subgingival plaque at the gingival margin.

Question 49: The cariogenic bacterium Streptococcus mutans produces which key virulence factor that enables its colonization of smooth tooth surfaces?

Collagenase for tissue invasion
Endotoxin (lipopolysaccharide)
Glucosyltransferases (GTFs) that synthesize insoluble glucans from sucrose for biofilm adhesion (Correct answer)
Proteases that destroy immunoglobulins

Correct answer: Glucosyltransferases (GTFs) that synthesize insoluble glucans from sucrose for biofilm adhesion

S. mutans produces glucosyltransferases (GTFs) that catalyze the synthesis of insoluble glucan polymers from sucrose, enabling firm adhesion to smooth tooth surfaces and forming the scaffold of cariogenic biofilm.

Question 50: Which of the following is considered the primary etiologic factor for periodontal disease?

Genetic predisposition
Bacterial plaque biofilm (Correct answer)
Poorly controlled diabetes
Tobacco use

Correct answer: Bacterial plaque biofilm

While genetics, smoking, and systemic diseases like diabetes are significant risk factors that modify the host response, bacterial plaque biofilm is universally recognized as the primary initiating factor for gingivitis and periodontitis.

Question 51: Which structure forms the floor of the nasal cavity and the roof of the oral cavity?

Hard palate (Correct answer)
Ethmoid plate
Pterygoid plate
Vomer

Correct answer: Hard palate

The hard palate, formed by the palatine processes of the maxilla and the horizontal plates of the palatine bones, separates the oral and nasal cavities.

Question 52: Which property best describes the ability of a dental material to withstand repeated masticatory loads without fracturing over time?

Fatigue resistance (Correct answer)
Hardness
Modulus of elasticity
Compressive strength

Correct answer: Fatigue resistance

Fatigue resistance refers to a material's ability to withstand cyclic or repeated loading below its ultimate strength without failure. In the oral environment, restorations endure thousands of masticatory cycles daily, so fatigue resistance — not single-load compressive strength — determines long-term clinical durability.

Question 53: Patients taking phenytoin (Dilantin) for seizure control may develop which notable oral side effect?

Drug-influenced gingival enlargement (gingival overgrowth) (Correct answer)
Geographic tongue
Angular cheilitis
Hairy leukoplakia

Correct answer: Drug-influenced gingival enlargement (gingival overgrowth)

Phenytoin (Dilantin) is the classic cause of drug-influenced gingival enlargement, affecting up to 50% of patients; excellent oral hygiene minimizes its severity.

Question 54: A dental hygienist is critically appraising a research article about a new diagnostic test for periodontal disease. The hygienist is evaluating if the researchers were blinded to the results of the 'gold standard' diagnostic method when interpreting the new test's results. This action is primarily aimed at assessing which type of bias?

Selection bias
Detection bias (Correct answer)
Performance bias
Attrition bias

Correct answer: Detection bias

Detection bias (or ascertainment bias) occurs when the assessment of outcomes is influenced by knowledge of which group a participant is in. Blinding the outcome assessors to the 'gold standard' results helps prevent their interpretation of the new test from being biased.

Question 55: On a panoramic radiograph, the 'ghost image' artifact is caused by:

Metallic objects left on the patient's body
A radiopaque structure on the contralateral side projecting across the midline at a higher and more blurred level (Correct answer)
Movement of the patient during the exposure
Film/sensor placement outside the focal trough

Correct answer: A radiopaque structure on the contralateral side projecting across the midline at a higher and more blurred level

Ghost images in panoramic radiography are reversed, magnified, blurred secondary images of radiopaque structures located on the opposite side of the beam path that appear above and blurred compared to the primary image.

Question 56: Subgingival irrigation as an adjunct to scaling and root planing delivers antimicrobial agents to:

Supragingival plaque only
Cementum surface for chemical root conditioning
The base of the periodontal pocket to disrupt residual biofilm and reduce microbial load (Correct answer)
The bloodstream via mucosal absorption

Correct answer: The base of the periodontal pocket to disrupt residual biofilm and reduce microbial load

Subgingival irrigation delivers antimicrobial solutions (chlorhexidine, povidone-iodine) directly to the base of periodontal pockets to reduce the bacterial load that instruments cannot fully access.

Question 57: Angular cheilitis at the corners of the mouth is most commonly associated with infection by:

HPV
Candida albicans (Correct answer)
Herpes simplex virus
Streptococcus pyogenes

Correct answer: Candida albicans

Angular cheilitis is most commonly caused by Candida albicans, often exacerbated by nutritional deficiencies, vitamin B12 deficiency, or ill-fitting dentures.

Question 58: Erythroplakia is clinically significant because it has a higher malignant transformation rate than which lesion?

Fibroma
Papilloma
Leukoplakia (Correct answer)
Mucocele

Correct answer: Leukoplakia

Erythroplakia carries a significantly higher rate of malignant transformation than leukoplakia and should be biopsied promptly.

Question 59: According to OSHA, contaminated sharps must be disposed of in:

Double-bagged red biohazard trash bags
Sealed rigid plastic containers filled with bleach solution
Puncture-resistant, leak-proof containers labeled with the biohazard symbol (Correct answer)
Standard medical waste bags with a sharps-only label

Correct answer: Puncture-resistant, leak-proof containers labeled with the biohazard symbol

OSHA requires contaminated sharps to be placed immediately in closable, puncture-resistant, leak-proof containers labeled with the biohazard symbol or color-coded red.

Question 60: Which pharmacologic effect of epinephrine accounts for its use as a vasoconstrictor in local anesthetic solutions?

Alpha-1 receptor stimulation causing vasoconstriction (Correct answer)
Histamine H1 receptor antagonism
Muscarinic receptor blockade
Beta-2 receptor stimulation causing vasodilation

Correct answer: Alpha-1 receptor stimulation causing vasoconstriction

Epinephrine acts on alpha-1 adrenergic receptors in peripheral vasculature to cause vasoconstriction, reducing systemic absorption of the local anesthetic.

Question 61: Which federal agency is primarily responsible for monitoring the nation's oral health through surveillance systems such as NHANES?

Indian Health Service (IHS)
National Institute of Dental and Craniofacial Research (NIDCR)
Food and Drug Administration (FDA)
Centers for Disease Control and Prevention (CDC) (Correct answer)

Correct answer: Centers for Disease Control and Prevention (CDC)

The CDC conducts the National Health and Nutrition Examination Survey (NHANES), which includes oral health examinations and is the primary source of national oral health surveillance data.

Question 62: A periapical radiograph showing a well-defined, unilocular radiolucency associated with the crown of an unerupted tooth is MOST consistent with:

Dentigerous (follicular) cyst (Correct answer)
Ameloblastoma
Odontogenic keratocyst
Adenomatoid odontogenic tumor

Correct answer: Dentigerous (follicular) cyst

A dentigerous (follicular) cyst is the most common odontogenic cyst arising from the follicle surrounding an unerupted tooth, presenting as a well-defined unilocular radiolucency attached at the cementoenamel junction.

Question 63: The buccinator muscle is innervated by which nerve?

Mylohyoid nerve — motor
Buccal branch of the trigeminal nerve (CN V3) — motor
Buccal branch of the facial nerve (CN VII) — motor (Correct answer)
Inferior alveolar nerve (CN V3) — motor

Correct answer: Buccal branch of the facial nerve (CN VII) — motor

Although the buccal branch of CN V3 provides sensory innervation to the cheek mucosa and skin, the buccinator muscle itself is a muscle of facial expression and is therefore innervated motorly by the buccal branch of the facial nerve (CN VII). This is a common source of confusion on dental board examinations.

Question 64: All of the following are considered non-modifiable risk factors for periodontal disease EXCEPT:

Age
Genetic predisposition
Osteoporosis
Stress (Correct answer)

Correct answer: Stress

Stress is considered a modifiable risk factor because individuals can potentially alter their coping mechanisms or reduce stressors, which can in turn affect their immune response and oral hygiene habits. Age, genetic factors, and osteoporosis are generally considered non-modifiable.

Question 65: The Early and Periodic Screening, Diagnostic, and Treatment (EPSDT) benefit, which ensures comprehensive dental services for eligible individuals under age 21, is a mandatory component of which federal program?

Tricare
Medicaid (Correct answer)
Children's Health Insurance Program (CHIP)
Medicare

Correct answer: Medicaid

The EPSDT benefit is a key provision of Medicaid for enrollees under the age of 21. It requires states to provide a comprehensive set of health services, including necessary dental care, to prevent and treat health problems early. While CHIP also covers children's dental care, the EPSDT benefit with its specific requirements is a mandate under Medicaid.

Question 66: A new adult patient presents with a medical history of Down syndrome. During the intraoral examination, which of the following oral manifestations is the dental hygienist MOST likely to find?

A high number of carious lesions
Macroglossia (Correct answer)
An increased number of permanent teeth (hyperdontia)
Accelerated eruption of permanent teeth

Correct answer: Macroglossia

Macroglossia, or an enlarged tongue, is a common clinical finding in individuals with Down syndrome. [2, 5, 11] It can be a true enlargement or a relative macroglossia due to a smaller-than-normal oral cavity. Other common findings include delayed tooth eruption, congenitally missing teeth (hypodontia), and a lower caries risk, although they are at very high risk for severe periodontal disease. [6]

Question 67: Which name describes odontalgia more frequently?

Dentures
Toothache (Correct answer)
Gingivitis
Plaque

Correct answer: Toothache

Odontalgia is the medical term for tooth pain. It directly translates from Greek as 'tooth' (odon) and 'pain' (algia). Therefore, 'toothache' is the most common and direct description of odontalgia, referring to any pain experienced in or around a tooth.

Question 68: The stylohyoid ligament is a remnant of which pharyngeal arch cartilage?

Fourth arch cartilage
Second arch (Reichert's cartilage) (Correct answer)
First arch (Meckel's cartilage)
Third arch cartilage

Correct answer: Second arch (Reichert's cartilage)

The stylohyoid ligament is a fibrous remnant of the second pharyngeal arch (Reichert's) cartilage, extending from the styloid process to the lesser horn of the hyoid.

Question 69: Which nerve is anesthetized by an inferior alveolar nerve block that also blocks the lingual nerve?

Posterior superior alveolar nerve
Mental nerve
Long buccal nerve
Lingual nerve (Correct answer)

Correct answer: Lingual nerve

During an inferior alveolar nerve block, the lingual nerve lies just anteromedial to the inferior alveolar nerve and is anesthetized by diffusion of anesthetic solution.

Question 70: According to standard precautions, gloves must be changed:

Between patients and when torn or punctured (Correct answer)
At the end of each clinical session
Only when visibly contaminated with blood
Every 30 minutes during patient care

Correct answer: Between patients and when torn or punctured

Standard precautions require glove changes between each patient and immediately if gloves are torn or punctured during care.

Question 71: In program evaluation, 'process evaluation' measures:

Changes in disease incidence
Cost-effectiveness of the intervention
Long-term health outcomes
Whether the program was delivered as planned (Correct answer)

Correct answer: Whether the program was delivered as planned

Process evaluation assesses fidelity of implementation — whether program activities were carried out as intended.

Question 72: A patient on chronic SSRI therapy undergoing periodontal surgery should be monitored for which drug interaction if an NSAID is prescribed post-operatively?

Increased risk of GI bleeding due to synergistic platelet inhibition (Correct answer)
Serotonin syndrome risk from combined therapy
NSAID-induced hypertension masked by SSRI
Reduced NSAID efficacy due to enzyme induction

Correct answer: Increased risk of GI bleeding due to synergistic platelet inhibition

SSRIs inhibit platelet serotonin uptake, impairing aggregation; NSAIDs also inhibit platelets, creating a synergistic risk of GI and post-operative bleeding.

Question 73: The submandibular gland's excretory duct (Wharton's duct) opens into the oral cavity at which structure?

Parotid papilla opposite the upper second molar
Sublingual caruncle at the base of the lingual frenum (Correct answer)
Soft palate adjacent to the uvula
Lateral wall of the oropharynx

Correct answer: Sublingual caruncle at the base of the lingual frenum

Wharton's duct travels anteriorly along the floor of the mouth and opens at the sublingual caruncle (a small papilla) on either side of the lingual frenum, near the midline of the floor of the mouth.

Question 74: The color stability of composite resins is primarily affected by which process over time?

Thermal contraction of the restoration
Calcium loss from the inorganic filler
Oxidative discoloration of resin matrix and water sorption (Correct answer)
Fluoride release causing surface staining

Correct answer: Oxidative discoloration of resin matrix and water sorption

Composite resins undergo color change primarily due to oxidation of the organic resin matrix and water sorption, which causes swelling and softening and can trap extrinsic stains.

Question 75: Interproximal bone loss appearing parallel to the cementoenamel junction (CEJ) on a bitewing radiograph is classified as:

Horizontal bone loss (Correct answer)
Angular bone loss
Vertical bone loss
Furcation involvement

Correct answer: Horizontal bone loss

Horizontal bone loss occurs when bone resorption proceeds evenly, resulting in a pattern parallel to the CEJ.

Question 76: A patient presents with a probing depth of 6 mm on the mesial-buccal of tooth #30. The gingival margin is located 2 mm coronal to the cementoenamel junction (CEJ). What is the calculated clinical attachment loss (CAL) for this site?

6 mm
8 mm
4 mm (Correct answer)
2 mm

Correct answer: 4 mm

To calculate Clinical Attachment Loss (CAL) when the gingival margin is coronal to the CEJ (indicating gingival enlargement or a pseudopocket), you subtract the distance from the gingival margin to the CEJ from the probing depth. In this case: 6 mm (Probing Depth) - 2 mm (Gingival Margin to CEJ) = 4 mm CAL.

Question 77: The Gracey curette, a series of area-specific periodontal instruments still widely used today, is credited to which developer?

Charles Bass
Paul Keyes
Clayton H. Gracey (Correct answer)
Alfred Fones

Correct answer: Clayton H. Gracey

Dr. Clayton H. Gracey designed the Gracey curettes in the 1930s and 1940s; each instrument in the series is specifically angled for use on particular tooth surfaces.

Question 78: In research design, a randomized controlled trial (RCT) is considered the gold standard because it:

Is the least expensive study design
Always uses a double-blind design
Randomly assigns subjects to experimental and control groups, minimizing selection bias and confounding variables (Correct answer)
Does not require a control group

Correct answer: Randomly assigns subjects to experimental and control groups, minimizing selection bias and confounding variables

Randomization ensures that both known and unknown confounding variables are distributed equally between groups by chance, making the RCT the most powerful design for establishing causality.

Question 79: The Wilkins Periodontal Probe, known for its unique color-coded banding, was developed by which dental hygienist?

Linda Boyd
Esther M. Wilkins, whose landmark textbook 'Clinical Practice of the Dental Hygienist' has been the standard dental hygiene reference for over 60 years (Correct answer)
Irene Newman
Alfred Fones

Correct answer: Esther M. Wilkins, whose landmark textbook 'Clinical Practice of the Dental Hygienist' has been the standard dental hygiene reference for over 60 years

Esther M. Wilkins authored the definitive dental hygiene textbook 'Clinical Practice of the Dental Hygienist' (first edition 1959) and contributed significantly to dental hygiene instrumentation.

Question 80: What is the primary purpose of using a cavity varnish under a zinc phosphate cement base in a deep preparation?

To seal dentinal tubules and reduce pulpal irritation from cement acids (Correct answer)
To increase the thickness of the cement base for thermal insulation
To accelerate the setting reaction of the zinc phosphate cement
To chemically bond the cement to dentin

Correct answer: To seal dentinal tubules and reduce pulpal irritation from cement acids

Cavity varnish — a resin dissolved in a volatile solvent — is applied to seal exposed dentinal tubules before placing zinc phosphate cement. This reduces the penetration of free phosphoric acid from the unset cement into the pulp, minimizing postoperative sensitivity and pulpal inflammation.

Question 81: Which of the following study designs is considered the highest level of evidence for determining the effectiveness of a therapeutic intervention in evidence-based dental hygiene practice?

Case-control study
Cohort study
Expert opinion
Systematic review of randomized controlled trials (Correct answer)

Correct answer: Systematic review of randomized controlled trials

Systematic reviews of randomized controlled trials (RCTs) are at the top of the evidence hierarchy. They synthesize the results of multiple high-quality RCTs, providing a more comprehensive and reliable conclusion than any single study.

Question 82: The principle behind guided tissue regeneration (GTR) is to:

Eliminate pocket depth by resecting bone to a more apical level
Apply growth factors to stimulate cementum formation only
Use a membrane to exclude epithelium and allow periodontal ligament cells to repopulate the defect (Correct answer)
Graft bone from a donor site to fill the defect

Correct answer: Use a membrane to exclude epithelium and allow periodontal ligament cells to repopulate the defect

GTR uses barrier membranes to exclude fast-growing epithelium and connective tissue, allowing slower-growing periodontal ligament and bone cells to repopulate the defect for true regeneration.

Question 83: Under the doctrine of respondeat superior, which of the following statements is TRUE?

A dental hygienist is personally immune from liability when acting under a dentist's direct supervision
A written employment contract eliminates the employer's vicarious liability
An employer may be held legally responsible for negligent acts committed by employees within the scope of their employment (Correct answer)
The supervising dentist alone bears all liability for any patient injury regardless of who performed the act

Correct answer: An employer may be held legally responsible for negligent acts committed by employees within the scope of their employment

Respondeat superior ('let the master answer') holds employers vicariously liable for employees' negligent acts performed within the scope of employment. However, the employee (dental hygienist) may also retain personal liability.

Question 84: What is the primary purpose of root planing during SRP?

Remove enamel irregularities to prevent plaque retention
Polish the root surface to a mirror finish
Remove cementum containing endotoxins and create a smooth, hard surface to promote tissue reattachment (Correct answer)
Open the sulcus to allow better subgingival irrigation

Correct answer: Remove cementum containing endotoxins and create a smooth, hard surface to promote tissue reattachment

Root planing removes contaminated cementum containing bacterial endotoxins and creates a clean, smooth root surface that promotes reattachment of connective tissue fibers.

Question 85: What level of disinfection is required for clinical contact surfaces in the dental operatory?

Intermediate-level disinfection (Correct answer)
Low-level disinfection
Sterilization
High-level disinfection

Correct answer: Intermediate-level disinfection

Clinical contact surfaces require intermediate-level disinfection using an EPA-registered hospital disinfectant with a tuberculocidal claim.

Question 86: Which of the following best describes 'pseudopockets' (false pockets)?

Pockets associated with furcation involvement
Increased sulcus depth caused by coronal enlargement of gingiva without apical migration of junctional epithelium (Correct answer)
Pockets created by gingival recession exposing root surfaces
Pockets formed by apical migration of junctional epithelium with bone loss

Correct answer: Increased sulcus depth caused by coronal enlargement of gingiva without apical migration of junctional epithelium

Pseudopockets result from gingival enlargement (tissue swells coronally) rather than apical migration of attachment; they represent increased probing depth without true attachment loss.

Question 87: A 55-year-old patient reports a persistent, non-productive dry cough that started several weeks after they began a new medication. They also note experiencing xerostomia. Which class of medication is MOST likely responsible for these side effects?

Beta-blockers
Diuretics
Calcium channel blockers
ACE inhibitors (Correct answer)

Correct answer: ACE inhibitors

A persistent dry cough is a well-known and common side effect of Angiotensin-Converting Enzyme (ACE) inhibitors, such as lisinopril or enalapril. While many antihypertensives can cause xerostomia, the combination of a dry mouth and a characteristic dry cough strongly points towards an ACE inhibitor. [10, 14, 29]

Question 88: A patient with a history of head and neck radiation therapy (≥60 Gy) presents for a hygiene appointment 2 years post-treatment. Which complication requires the most careful monitoring?

Osteoradionecrosis risk, severe xerostomia, radiation caries, and trismus (Correct answer)
Increased fluorosis risk
Delayed tooth eruption only
Enhanced wound healing

Correct answer: Osteoradionecrosis risk, severe xerostomia, radiation caries, and trismus

High-dose radiation to the head and neck causes permanent damage to salivary glands (xerostomia), vascular supply of bone (osteoradionecrosis risk), and masticatory muscles (trismus), with a lifelong risk of radiation caries.

Question 89: The 'iceberg concept' in epidemiology refers to:

The tip of a disease outbreak in polar regions
The visible cases of disease representing only a fraction of total cases (Correct answer)
The gradual rise of chronic disease over time
The cold storage of biological specimens

Correct answer: The visible cases of disease representing only a fraction of total cases

The iceberg concept illustrates that clinically apparent disease cases are far fewer than the total cases existing in a population.

Question 90: Geographic tongue is clinically referred to as:

Hairy tongue
Fissured tongue
Benign migratory glossitis (Correct answer)
Median rhomboid glossitis

Correct answer: Benign migratory glossitis

Geographic tongue, or benign migratory glossitis, presents as irregular erythematous patches with white-yellow borders that migrate across the dorsal tongue.

Question 91: Which of the following describes an appropriate modification when providing dental hygiene care to a patient who is wheelchair-bound and cannot be transferred to the dental chair?

Refusing to provide care until the patient can be transferred
Only providing preventive education without any clinical procedures
Using only a hand mirror without powered instrumentation
Treating the patient in their wheelchair using a headrest attachment, positioning the clinician behind the patient (Correct answer)

Correct answer: Treating the patient in their wheelchair using a headrest attachment, positioning the clinician behind the patient

Patients who cannot be transferred should be treated in their wheelchair using a portable headrest and ergonomic positioning, with full access to oral cavity when possible.

Question 92: On a full-mouth series of radiographs, the most common pattern of alveolar bone loss associated with generalized chronic periodontitis is:

Hemiseptal defects with three-wall components
Angular (vertical) bone loss
Fenestration defects at the buccal plate
Horizontal bone loss parallel to the CEJ (Correct answer)

Correct answer: Horizontal bone loss parallel to the CEJ

Horizontal bone loss, in which the alveolar crest is reduced in height but remains roughly parallel to a line connecting adjacent CEJs, is the most prevalent radiographic pattern in generalized chronic periodontitis. Vertical/angular defects are less common and often associated with localized aggressive disease or specific risk factors.

Question 93: Which muscle protracts the mandible?

Masseter
Medial pterygoid
Temporalis
Lateral pterygoid (Correct answer)

Correct answer: Lateral pterygoid

Both heads of the lateral pterygoid acting bilaterally protract (protrude) the mandible by pulling the condyle and articular disc anteriorly.

Question 94: Aphthous stomatitis (canker sores) characteristically occur on:

Hard palate
Non-keratinized movable mucosa (Correct answer)
Dorsal tongue
Keratinized attached gingiva

Correct answer: Non-keratinized movable mucosa

Aphthous ulcers occur on non-keratinized, movable oral mucosa such as the buccal mucosa, labial mucosa, and floor of the mouth.

Question 95: The Ottawa Charter for Health Promotion (1986) emphasizes that health is:

A resource for everyday life, not the objective of living (Correct answer)
Primarily a medical responsibility
Best achieved through clinical interventions alone
Solely the absence of disease and infirmity

Correct answer: A resource for everyday life, not the objective of living

The Ottawa Charter defines health as a positive concept and a resource for everyday life, emphasizing social and personal resources.

Question 96: Which mechanism best explains why erythromycin increases the plasma level of cyclosporine in transplant patients receiving dental antibiotic therapy?

Erythromycin displaces cyclosporine from plasma proteins
Erythromycin inhibits CYP3A4, reducing cyclosporine metabolism (Correct answer)
Erythromycin increases GI absorption of cyclosporine
Erythromycin reduces renal clearance of cyclosporine

Correct answer: Erythromycin inhibits CYP3A4, reducing cyclosporine metabolism

Erythromycin is a potent CYP3A4 inhibitor, which reduces first-pass and hepatic metabolism of cyclosporine, elevating its plasma concentration.

Question 97: A dental hygienist discovers that a colleague has been charting procedures that were not performed. What is the most appropriate initial action?

Alert the supervising dentist or practice owner about the discrepancy (Correct answer)
Confront the colleague privately and document the conversation
Ignore the situation to avoid workplace conflict
Report the colleague directly to the state dental board

Correct answer: Alert the supervising dentist or practice owner about the discrepancy

Reporting suspected fraud to the supervising dentist or practice owner is the appropriate first step within the organizational hierarchy before escalating externally.

Question 98: Which drug interaction is MOST critical for a dental hygienist to recognize when a patient is taking monoamine oxidase inhibitors (MAOIs) for depression?

MAOIs reduce the efficacy of local anesthetics
MAOIs can cause hypertensive crisis if combined with indirectly-acting sympathomimetic agents, and dangerous serotonin syndrome if combined with meperidine (Correct answer)
MAOIs cause increased bleeding with NSAIDs
MAOIs cause gingival enlargement

Correct answer: MAOIs can cause hypertensive crisis if combined with indirectly-acting sympathomimetic agents, and dangerous serotonin syndrome if combined with meperidine

MAO inhibitors prevent breakdown of catecholamines and serotonin; indirect sympathomimetics can cause severe hypertensive crisis, and meperidine (Demerol) can trigger fatal serotonin syndrome.

Question 99: Which U.S. state was the first to legally license dental hygienists, doing so in 1917?

Massachusetts
Connecticut (Correct answer)
Ohio
New York

Correct answer: Connecticut

Connecticut passed the first dental hygiene practice act in 1917, formally recognizing dental hygiene as a licensed profession and setting the precedent for other states.

Question 100: Which of the following is a characteristic radiographic feature of condensing osteitis?

Well-defined radiopaque mass at the apex of a tooth with pulpal pathology (Correct answer)
Radiolucency at the apex with loss of lamina dura
Generalized decrease in bone density around multiple teeth
Multilocular radiolucency with scalloped borders

Correct answer: Well-defined radiopaque mass at the apex of a tooth with pulpal pathology

Condensing osteitis presents as a focal sclerotic bone reaction appearing as a well-defined radiopaque area at the apex of a tooth with chronic low-grade pulpal inflammation.

Question 101: Which instrument is used to condense amalgam into a prepared cavity?

Amalgam condenser (plugger) (Correct answer)
Carver
Matrix band
Burnisher

Correct answer: Amalgam condenser (plugger)

Amalgam condensers (pluggers) are used to firmly adapt amalgam increments to the cavity walls and floor, eliminating voids and adapting the material to line angles.

Question 102: Which fluoride delivery method provides the HIGHEST concentration of fluoride?

Fluoride toothpaste (1,000–1,500 ppm)
Professionally applied fluoride varnish (22,600 ppm) (Correct answer)
Fluoride mouth rinse (225 ppm)
Community water fluoridation (0.7 ppm)

Correct answer: Professionally applied fluoride varnish (22,600 ppm)

Professionally applied fluoride varnish contains approximately 22,600 ppm fluoride, the highest concentration among common delivery methods.

Question 103: A patient has gingival recession of 2 mm and a probing depth of 4 mm. What is the clinical attachment level?

4 mm
2 mm
6 mm (Correct answer)
8 mm

Correct answer: 6 mm

When recession is present, CAL = probing depth + recession (4 mm + 2 mm = 6 mm).

Question 104: When taking an elastomeric impression, the tray adhesive should be applied:

Immediately before loading the tray with impression material
At least 15 minutes before taking the impression to allow it to dry completely (Correct answer)
After placing the impression material in the tray
Only for hydrophilic impression materials

Correct answer: At least 15 minutes before taking the impression to allow it to dry completely

Tray adhesive for elastomeric impressions must dry for at least 15 minutes to form a tacky film that chemically bonds to the impression material and prevents separation from the tray.

Question 105: The 'attributable risk' in epidemiology measures:

The ratio of disease risk in exposed vs. unexposed groups
The probability of disease in the absence of exposure
The proportion of cases caused by chance
The excess risk due to the exposure (Correct answer)

Correct answer: The excess risk due to the exposure

Attributable risk (risk difference) quantifies the additional risk of disease that can be attributed to the specific exposure.

Question 106: Which oral lesion appears as a white, non-removable plaque on the oral mucosa that cannot be attributed to any other known disease?

Linea alba
Candidiasis
Fordyce spots
Leukoplakia (Correct answer)

Correct answer: Leukoplakia

Leukoplakia is defined as a white patch that cannot be scraped off and has no other identifiable cause.

Question 107: A patient with Down syndrome presents for a routine cleaning. Which cardiac condition is most commonly associated with Down syndrome that requires antibiotic prophylaxis consideration?

Tricuspid regurgitation
Atrioventricular septal defect (Correct answer)
Pulmonary stenosis
Mitral valve prolapse

Correct answer: Atrioventricular septal defect

Atrioventricular septal defect (AVSD) is the most common congenital heart defect in patients with Down syndrome, occurring in approximately 40% of cases.

Question 108: The principle of justice in public health ethics requires that dental hygienists:

Prioritize efficiency over equity in program delivery
Exclude high-risk populations from prevention programs
Maximize benefits to the most affluent patients
Distribute oral health resources and burdens fairly across populations (Correct answer)

Correct answer: Distribute oral health resources and burdens fairly across populations

Justice demands fair distribution of health resources and equal consideration of community members regardless of socioeconomic status.

Question 109: Which type of bone cell is responsible for the resorption of mineralized bone matrix?

Osteocyte
Cementoblast
Osteoblast
Osteoclast (Correct answer)

Correct answer: Osteoclast

Osteoclasts are multinucleated cells derived from monocyte precursors that resorb bone by secreting acid and lysosomal enzymes into the resorption lacuna.

Question 110: This caries risk assessment tool offers instructions for determining the level of caries risk and choosing dental hygiene measures based on risk factor evaluation.

ASA
ADL
OSCAR
CAMBRA (Correct answer)

Correct answer: CAMBRA

CAMBRA stands for Caries Management By Risk Assessment. It is an evidence-based approach used in dentistry to assess an individual's risk for developing dental caries. Based on this assessment, specific preventive and therapeutic dental hygiene measures are then tailored to manage and reduce the patient's caries risk, making it a crucial tool for personalized oral health care.

Question 111: The mylohyoid line on the mandible serves as the attachment for which muscle?

Digastric anterior belly
Genioglossus
Mylohyoid (Correct answer)
Geniohyoid

Correct answer: Mylohyoid

The mylohyoid muscle attaches along the entire length of the mylohyoid line on the medial surface of the mandible, forming the floor of the mouth.

Question 112: During a periodontal examination, a patient shows 4 mm probing depths with no bone loss radiographically and bleeding on probing. This finding is consistent with:

Plaque-induced gingivitis on an intact periodontium (Correct answer)
Healthy periodontium
Initial periodontitis (Stage I)
Gingivitis on a reduced periodontium

Correct answer: Plaque-induced gingivitis on an intact periodontium

Probing depths of up to 4 mm with bleeding on probing but no radiographic bone loss or CAL indicates plaque-induced gingivitis, which is reversible with proper plaque control.

Question 113: Which epidemiological index is most commonly used to measure dental caries prevalence in community surveys?

OHI-S index
Gingival index
Russell's periodontal index
DMFT index (Correct answer)

Correct answer: DMFT index

The DMFT index (Decayed, Missing, Filled Teeth) is the standard WHO-endorsed tool for measuring caries experience in permanent dentition in community oral health surveys.

Question 114: Which prostaglandin is considered the PRIMARY lipid mediator of alveolar bone resorption in chronic inflammatory periodontal disease?

Prostaglandin I2 (prostacyclin)
Prostaglandin D2 (PGD2)
Thromboxane A2 (TXA2)
Prostaglandin E2 (PGE2) (Correct answer)

Correct answer: Prostaglandin E2 (PGE2)

PGE2 is the predominant prostaglandin detected at elevated concentrations in gingival crevicular fluid at active periodontitis sites. It stimulates osteoclast differentiation and activity by upregulating the RANK/RANKL pathway, making it the principal arachidonic acid–derived mediator of bone destruction in periodontal disease.

Question 115: A 70-year-old patient on bisphosphonate therapy for osteoporosis requires a tooth extraction. What is the primary concern?

Medication-related osteonecrosis of the jaw (MRONJ) (Correct answer)
Systemic infection risk
Increased risk of dry socket only
Prolonged bleeding due to drug interaction

Correct answer: Medication-related osteonecrosis of the jaw (MRONJ)

Bisphosphonate therapy suppresses osteoclast activity, impairing bone healing and creating risk for MRONJ following invasive oral procedures.

Question 116: The submandibular triangle contains the submandibular gland and which major nerve?

Glossopharyngeal nerve
Hypoglossal nerve only
Inferior alveolar nerve
Lingual nerve and facial artery (Correct answer)

Correct answer: Lingual nerve and facial artery

The submandibular (digastric) triangle contains the submandibular gland, facial artery and vein, and the lingual nerve, which passes around Wharton's duct.

Question 117: According to the 2017 World Workshop classification, periodontitis Grade C (rapid rate of progression) is supported by which indirect evidence finding?

Bone loss of less than 25% relative to root length
Radiographic bone loss percentage to patient age ratio greater than 1.0
Absence of systemic modifying factors such as diabetes or smoking
Heavy supra-gingival calculus deposits with minimal attachment loss (Correct answer)

Correct answer: Heavy supra-gingival calculus deposits with minimal attachment loss

Indirect evidence for Grade C includes a bone loss %/age ratio > 1.0, which suggests bone is being lost faster than expected for the patient's age. Direct evidence includes ≥ 2 mm of bone loss within 5 years. Heavy deposits with low destruction suggest Grade A (slow progression).

Question 118: The Spaulding classification system divides patient-care items into how many risk categories?

Four (sterile, high-level disinfected, clean, noncritical)
Five levels corresponding to disinfection requirements
Two (clean and contaminated)
Three (critical, semicritical, noncritical) (Correct answer)

Correct answer: Three (critical, semicritical, noncritical)

The Spaulding system uses three categories — critical, semicritical, and noncritical — to guide the appropriate level of reprocessing for dental instruments.

Question 119: A radiograph showing a widened periodontal ligament (PDL) space around the entire tooth is most consistent with:

Periapical abscess
Hypercementosis
Ankylosis
Occlusal trauma or bruxism (Correct answer)

Correct answer: Occlusal trauma or bruxism

Uniform widening of the PDL space around the entire root is a classic radiographic sign of occlusal trauma or bruxism causing increased tooth mobility.

Question 120: In epidemiological studies of oral health, what does the term 'confounding variable' mean?

The dependent variable in the study
Any variable that cannot be measured
A variable that directly causes the disease being studied
A variable that is associated with both the exposure and the outcome, distorting the apparent relationship between them (Correct answer)

Correct answer: A variable that is associated with both the exposure and the outcome, distorting the apparent relationship between them

A confounder is associated with the independent variable (exposure) and is an independent cause of the outcome, making it appear that the exposure causes the outcome when the true cause may be the confounder.

Question 121: A patient presents with 5-6 mm probing depths, bleeding on probing, and radiographic bone loss of 15-25%. Which AAP classification does this represent?

Stage I, Grade A
Stage III, Grade C
Stage II, Grade B (Correct answer)
Stage IV, Grade B

Correct answer: Stage II, Grade B

Stage II periodontitis is characterized by probing depths of 5-6 mm and radiographic bone loss of 15-33% with moderate complexity factors.

Question 122: Which surface of teeth shows the highest plaque scores in patients who are not motivated to practice oral hygiene?

Smooth buccal surfaces at the height of contour
Interproximal (proximal) surfaces and the gingival margin on all surfaces (Correct answer)
Occlusal pits and fissures
Cusp tips and incisal edges

Correct answer: Interproximal (proximal) surfaces and the gingival margin on all surfaces

Interproximal surfaces and areas near the gingival margin accumulate the most plaque because toothbrush bristles have limited access — these are also the most common sites for both caries and periodontal disease initiation.

Question 123: A county health department report states that there were 250 new cases of periodontal disease diagnosed in adults over age 65 during the year 2025. This statistic represents the disease's:

Incidence (Correct answer)
Morbidity
Mortality
Prevalence

Correct answer: Incidence

Incidence is the measure of the number of *new* cases of a disease that occur in a specific population over a specific period. Prevalence refers to the total number of existing cases (both new and old) at a point in time or over a period.

Question 124: Which oral hygiene aid is most recommended for cleaning under a fixed partial denture (bridge) pontic area?

Standard dental floss
Water flosser exclusively
Interdental brush only
Superfloss or floss threader (Correct answer)

Correct answer: Superfloss or floss threader

Superfloss or a floss threader allows patients to thread floss under the pontic of a fixed bridge to clean the gingival surface of the pontic and adjacent abutment margins.

Question 125: A patient is undergoing a full mouth series of radiographs. To adhere to the ALARA (As Low As Reasonably Achievable) principle, which of the following is the MOST effective way to protect the patient from unnecessary radiation exposure?

Using a round collimator
Using a D-speed film
Using a short, 8-inch position-indicating device (PID)
Using a lead apron with a thyroid collar (Correct answer)

Correct answer: Using a lead apron with a thyroid collar

While all aspects of technique are important, the most effective patient protection measure listed is the use of a lead apron and a thyroid collar. These items shield radiosensitive tissues (thyroid gland, reproductive organs) from scatter radiation during exposure. Rectangular collimation and faster film speeds (like F-speed) are also key components of ALARA, but the lead apron and thyroid collar are fundamental protective equipment.

Question 126: The Oral Hygiene Index-Simplified (OHI-S), developed by Greene and Vermillion, is calculated by combining scores from which two sub-indices?

Debris Index and Calculus Index (Correct answer)
Bleeding Index and Pocket Depth Index
Plaque Index and Gingival Index
Calculus Index and Probing Depth Index

Correct answer: Debris Index and Calculus Index

The OHI-S scores the amount of soft debris (Debris Index) and hard calculus deposits (Calculus Index) on six representative tooth surfaces, then averages each sub-index and sums them to produce an overall oral hygiene score.

Question 127: Which of the following is a frequent oral health complication in patients with cerebral palsy, directly resulting from their neuromuscular condition?

Delayed tooth eruption
Gingival hyperplasia
Enamel fluorosis
Bruxism and attrition (Correct answer)

Correct answer: Bruxism and attrition

Patients with cerebral palsy often experience involuntary muscle contractions and spasticity, which can lead to habitual, non-functional grinding (bruxism) and clenching. [4, 12] This can cause significant wear and tear on the occlusal surfaces of the teeth, known as attrition. While gingival hyperplasia can occur, it is typically a side effect of seizure medications (e.g., phenytoin) that some patients with cerebral palsy may take, not a direct result of the neuromuscular condition itself. [4]

Question 128: Which radiographic finding is most commonly associated with patients who have undergone head and neck radiation therapy?

Osteoradionecrosis presenting as radiolucent areas with irregular borders (Correct answer)
Pulp calcifications throughout dentition
Increased bone density in the mandible
Hypercementosis on posterior teeth

Correct answer: Osteoradionecrosis presenting as radiolucent areas with irregular borders

Radiation therapy damages the vascularity of bone, leading to osteoradionecrosis, which appears radiographically as irregular radiolucent areas.

Question 129: What are the main components of a tooth: enamel, cementum, pulp?

Bone
Nerve
Blood vessels
Dentin (Correct answer)

Correct answer: Dentin

The main components of a tooth include enamel (the outermost protective layer), cementum (covers the root surface), pulp (the innermost soft tissue containing nerves and blood vessels), and dentin. Dentin is the yellowish, bone-like tissue that lies beneath the enamel and cementum, forming the bulk of the tooth structure and surrounding the pulp chamber. It provides support and resilience to the tooth.

Question 130: A patient with schizophrenia takes an antipsychotic medication. Which oral side effect is most commonly associated with long-term antipsychotic use?

Hairy tongue
Angular cheilitis
Gingival hyperplasia
Xerostomia and subsequent increased caries risk (Correct answer)

Correct answer: Xerostomia and subsequent increased caries risk

Antipsychotic medications commonly cause xerostomia through anticholinergic effects, significantly elevating caries risk.

Question 131: Which historical figure is known as the 'Father of Modern Dentistry' and authored the first comprehensive dental textbook 'Le Chirurgien Dentiste' in 1728?

Horace Wells
Alfred Fones
G.V. Black
Pierre Fauchard (Correct answer)

Correct answer: Pierre Fauchard

Pierre Fauchard (1678–1761) was a French surgeon who published 'Le Chirurgien Dentiste' in 1728, establishing dentistry as a distinct scientific discipline.

Question 132: Oral squamous cell carcinoma most commonly arises at which intraoral site?

Buccal mucosa
Lateral border of tongue and floor of mouth (Correct answer)
Hard palate
Dorsal tongue

Correct answer: Lateral border of tongue and floor of mouth

The lateral border of the tongue and floor of the mouth are the most common sites for oral squamous cell carcinoma due to pooling of carcinogens.

Question 133: According to the Health Belief Model, which combination of perceptions is most likely to motivate a patient to adopt daily flossing?

High perceived susceptibility to periodontal disease and high perceived benefits of flossing (Correct answer)
Low perceived severity because the condition is 'just gum disease'
External cues to action without personal perceived susceptibility
High self-efficacy alone, regardless of perceived threat

Correct answer: High perceived susceptibility to periodontal disease and high perceived benefits of flossing

The Health Belief Model holds that behavior change requires individuals to perceive themselves as personally susceptible to a condition AND believe the recommended action will produce meaningful benefits; without both elements, motivation to act is typically insufficient.

Question 134: Which of the following is an example of fraudulent billing in dental practice?

Documenting periodontal charting that was completed during the appointment
Charging a patient the copay stated in their insurance plan
Submitting a claim for a procedure that was performed and documented
Billing for a prophylaxis when a full-mouth debridement was performed (Correct answer)

Correct answer: Billing for a prophylaxis when a full-mouth debridement was performed

Upcoding—billing for a more expensive procedure than what was actually performed—constitutes dental fraud.

Question 135: Which film speed is currently recommended by the ADA for intraoral radiography to minimize patient dose?

A-speed
D-speed (Ultra-speed)
E-speed (Ektaspeed)
F-speed (Insight) (Correct answer)

Correct answer: F-speed (Insight)

F-speed (Insight) film requires the least radiation exposure to produce a diagnostic image and is currently the fastest film speed recommended.

Question 136: Which of the following best describes the purpose of subgingival irrigation with antimicrobial agents during periodontal therapy?

To eliminate the need for re-evaluation
To reduce the subgingival microbial load as an adjunct to scaling (Correct answer)
To replace mechanical debridement
To cure chronic periodontitis

Correct answer: To reduce the subgingival microbial load as an adjunct to scaling

Subgingival irrigation with antimicrobials is an adjunct to, not a replacement for, mechanical debridement.

Question 137: Which of the following best describes 'junctional epithelium'?

Keratinized epithelium that forms the oral sulcular epithelium
Epithelium lining the outer surface of the gingiva
Non-keratinized epithelium that attaches the gingiva to the tooth surface (Correct answer)
Epithelium covering the alveolar mucosa

Correct answer: Non-keratinized epithelium that attaches the gingiva to the tooth surface

Junctional epithelium is a non-keratinized epithelium that forms the epithelial attachment at the base of the gingival sulcus, attaching to the tooth via hemidesmosomes.

Question 138: A patient taking monoamine oxidase inhibitors (MAOIs) requires dental care. Which drug combination poses the greatest risk?

Prilocaine with felypressin
Mepivacaine without vasoconstrictor
Articaine with epinephrine
Lidocaine with epinephrine (Correct answer)

Correct answer: Lidocaine with epinephrine

Epinephrine combined with MAOIs can cause a hypertensive crisis because MAOIs inhibit the breakdown of catecholamines, amplifying sympathomimetic effects.

Question 139: Respondeat superior is a legal doctrine that holds which party liable for an employee's negligent acts performed within the scope of employment?

The state dental board
The patient who was harmed
The employer or supervising dentist (Correct answer)
The employee who committed the negligent act

Correct answer: The employer or supervising dentist

Under respondeat superior, employers are vicariously liable for negligent acts their employees commit within the scope of their employment duties.

Question 140: Which oral manifestation is most characteristic of primary herpetic gingivostomatitis?

Painless red ulcers on hard palate
Painless white patches
Blue-black gingival discoloration
Widespread vesicles and ulcers with fever and lymphadenopathy (Correct answer)

Correct answer: Widespread vesicles and ulcers with fever and lymphadenopathy

Primary HSV-1 infection presents with multiple vesicles that rupture into ulcers, accompanied by fever, malaise, and cervical lymphadenopathy.

Question 141: The glossopharyngeal nerve (CN IX) provides taste sensation to which region of the tongue?

Lateral borders only
Posterior one-third (Correct answer)
Tip of the tongue
Anterior two-thirds

Correct answer: Posterior one-third

CN IX provides both taste and general sensation to the posterior one-third of the tongue via its lingual branches, including the circumvallate papillae.

Question 142: In Glickman's classification of furcation involvement, a Class II furcation is best described as a defect in which:

The probe enters the furcation but does not pass through to the opposite side (Correct answer)
The furcation involvement is visible clinically without instrumentation
The probe detects a slight horizontal component but cannot enter the furcation
The probe passes completely through the furcation from buccal to lingual

Correct answer: The probe enters the furcation but does not pass through to the opposite side

Class II furcation involvement means the horizontal probe penetrates into the furcation but is blocked before exiting the other side. Class I is a slight entry only; Class III is through-and-through; Class IV is through-and-through with visible recession.

Question 143: Which of the following best describes the recommended position for a patient's head during a panoramic radiograph to ensure proper positioning in the focal trough?

Frankfort plane parallel to the floor with the midsagittal plane perpendicular to the floor (Correct answer)
Chin resting on the chin rest with the head tilted forward 15 degrees
Head rotated 10 degrees to the right for right-side detail
Head tilted back 20 degrees with chin raised

Correct answer: Frankfort plane parallel to the floor with the midsagittal plane perpendicular to the floor

Proper panoramic positioning requires the Frankfort plane (ala-tragus line) to be parallel to the floor and the midsagittal plane to be perpendicular to the floor to ensure symmetrical positioning within the focal trough.

Question 144: The nasopalatine nerve exits the palate through which foramen?

Lesser palatine foramen
Incisive foramen (Correct answer)
Greater palatine foramen
Mental foramen

Correct answer: Incisive foramen

The nasopalatine nerve passes through the incisive foramen to supply the mucosa of the anterior hard palate behind the maxillary incisors.

Question 145: Which analgesic should be avoided in a patient with aspirin-exacerbated respiratory disease (AERD/Samter's triad)?

Acetaminophen (paracetamol)
Codeine
Ibuprofen and all NSAIDs (including aspirin) (Correct answer)
Tramadol

Correct answer: Ibuprofen and all NSAIDs (including aspirin)

Patients with AERD (Samter's triad: asthma, nasal polyps, aspirin sensitivity) experience bronchospasm with all NSAIDs that inhibit COX-1, including ibuprofen; acetaminophen is generally safe.

Question 146: Which metabolic pathway produces ATP most efficiently under aerobic conditions?

Oxidative phosphorylation via the electron transport chain (Correct answer)
Pentose phosphate pathway
Glycolysis alone
Beta-oxidation of fatty acids only

Correct answer: Oxidative phosphorylation via the electron transport chain

Oxidative phosphorylation in the mitochondria generates approximately 30–32 ATP per glucose molecule, far exceeding the 2 ATP from anaerobic glycolysis.

Question 147: What is the primary advantage of using polyvinyl siloxane (PVS) impression material over polysulfide?

Lower cost
Greater dimensional stability over time (Correct answer)
Faster set time only
Better compatibility with latex gloves

Correct answer: Greater dimensional stability over time

PVS impression materials are addition silicones that exhibit excellent dimensional stability and can be poured multiple times without significant distortion.

Question 148: Which radiation protection device is most critical for the dental radiographer to wear during X-ray exposures?

Thyroid collar
Dosimeter badge (Correct answer)
Lead apron
Leaded gloves

Correct answer: Dosimeter badge

A dosimetry badge (personnel monitoring device) is the most critical protective measure because it records actual radiation exposure to ensure dose limits are not exceeded.

Question 149: Erythroplakia carries a greater risk of malignant transformation compared to leukoplakia because:

It is caused by tobacco exclusively
It is always infected with Candida
It shows a higher rate of severe dysplasia or carcinoma in situ (Correct answer)
It always involves the floor of the mouth

Correct answer: It shows a higher rate of severe dysplasia or carcinoma in situ

Erythroplakia has a malignant transformation rate of up to 90%, far exceeding that of leukoplakia, due to the high prevalence of severe epithelial dysplasia.

Question 150: When a dental hygienist documents 'patient tolerated procedure well' without recording specific clinical findings, this practice:

Is considered thorough and legally protective documentation
May be legally insufficient because it lacks specific, objective clinical information (Correct answer)
Is acceptable because it saves documentation time
Fully satisfies the standard of care for clinical recordkeeping

Correct answer: May be legally insufficient because it lacks specific, objective clinical information

Vague entries without specific clinical data may be considered legally insufficient; thorough documentation requires objective, factual, and specific entries.

Question 151: The two most significant risk factors for oral squamous cell carcinoma are:

Stress and autoimmune conditions
Tobacco use and alcohol consumption (Correct answer)
Sugar intake and poor hygiene
Fluoride exposure and genetics

Correct answer: Tobacco use and alcohol consumption

Tobacco use and alcohol consumption are the primary risk factors for oral squamous cell carcinoma, and their combined effect is synergistic.

Question 152: An oral health program that provides fluoride varnish to WIC participants demonstrates which level of prevention?

Tertiary prevention
Secondary prevention
Primary prevention (Correct answer)
Quaternary prevention

Correct answer: Primary prevention

Fluoride varnish applied to healthy or at-risk children prevents caries from occurring, making it a primary prevention intervention.

Question 153: Which autoimmune disease causes bilateral, reticular white striations on the buccal mucosa known as Wickham's striae?

Mucous membrane pemphigoid
Pemphigus vulgaris
Lupus erythematosus
Lichen planus (Correct answer)

Correct answer: Lichen planus

Oral lichen planus classically presents as bilateral, interlacing white lines (Wickham's striae) on the buccal mucosa.

Question 154: A patient's porcelain-fused-to-metal crown shows repeated porcelain fracture at the incisal edge. What is the most likely cause?

Overcontouring of the gingival margin
Insufficient metal support (coping) beneath the porcelain (Correct answer)
Using feldspathic porcelain instead of leucite-reinforced
Too thick a layer of opaque porcelain

Correct answer: Insufficient metal support (coping) beneath the porcelain

Porcelain requires adequate metal support; without it, flexure of the metal coping during function creates tensile stresses in the brittle porcelain, causing fracture.

Question 155: A biopsy of an oral ulcer shows acantholysis and loss of intercellular bridges between keratinocytes. Which autoimmune condition does this suggest?

Mucous membrane pemphigoid
Pemphigus vulgaris (Correct answer)
Erythema multiforme
Lichen planus

Correct answer: Pemphigus vulgaris

Pemphigus vulgaris is caused by autoantibodies against desmoglein, resulting in acantholysis (separation of keratinocytes) and intraepithelial vesicle formation.

Question 156: Which oral hygiene aid is MOST recommended for a patient with wide interproximal spaces and exposed root furcations?

Interdental brush (Correct answer)
Dental floss
Floss threader
Toothpick

Correct answer: Interdental brush

Interdental brushes are the most effective aid for cleaning wide spaces, exposed furcations, and around orthodontic appliances.

Question 157: Extrinsic tooth staining from chlorhexidine mouthrinse occurs through which mechanism?

Chlorhexidine binds to anionic salivary proteins and reacts with dietary chromogens (tannins, polyphenols) to form insoluble brown-black pigment deposits on tooth surfaces (Correct answer)
Fluoride-chlorhexidine chemical reaction on enamel
Direct oxidation of tooth enamel by chlorhexidine
Reduction of salivary flow leading to plaque accumulation

Correct answer: Chlorhexidine binds to anionic salivary proteins and reacts with dietary chromogens (tannins, polyphenols) to form insoluble brown-black pigment deposits on tooth surfaces

Chlorhexidine (cationic) binds to salivary proteins and tooth surfaces, then reacts with dietary tannins and polyphenols (coffee, tea, red wine) through condensation reactions to form brown pigments.

Question 158: The chorda tympani nerve is a branch of which cranial nerve?

CN IX
CN VII (Correct answer)
CN V3
CN X

Correct answer: CN VII

The chorda tympani is a branch of the facial nerve (CN VII) that carries taste from the anterior two-thirds of the tongue and preganglionic parasympathetic fibers to submandibular and sublingual glands.

Question 159: A patient with G6PD deficiency is at increased risk for hemolytic anemia when taking which drug commonly used in dentistry?

Amoxicillin
Bupivacaine
Lidocaine
Prilocaine (Correct answer)

Correct answer: Prilocaine

Prilocaine's metabolite o-toluidine can cause methemoglobinemia and trigger hemolysis in G6PD-deficient patients.

Question 160: How frequently does the CDC recommend biological (spore) monitoring of dental sterilizers?

Monthly
Weekly (Correct answer)
Annually or only when problems are suspected
After every sterilization cycle

Correct answer: Weekly

The CDC recommends weekly biological monitoring of sterilizers using spore tests to verify ongoing sterilization effectiveness.

Question 161: In epidemiological terms, 'incidence' refers to:

The total number of existing cases at a given point in time
The proportion of a population that is immune to a disease
The number of new cases of a disease occurring in a defined population over a specific time period (Correct answer)
The death rate attributable to a disease

Correct answer: The number of new cases of a disease occurring in a defined population over a specific time period

Incidence measures new cases arising in a population over a defined time period, distinguishing it from prevalence, which counts all existing cases.

Question 162: The US Public Health Service currently recommends community water fluoridation at:

0.3 ppm
0.7 ppm (Correct answer)
1.2 ppm
2.0 ppm

Correct answer: 0.7 ppm

Since 2015, the USPHS recommends a single optimal fluoride level of 0.7 mg/L (ppm) in community drinking water to prevent caries while minimizing fluorosis.

Question 163: The most recognizable form of oral lichen planus presents as:

Yellow nodules
Blue-black macules
Red velvety patches
White interlacing lines (Wickham's striae) (Correct answer)

Correct answer: White interlacing lines (Wickham's striae)

The reticular form of oral lichen planus is the most common presentation, characterized by white interlacing lines called Wickham's striae on the buccal mucosa.

Question 164: Which antibiotic prophylaxis regimen is currently recommended by the AHA for a cardiac patient unable to take oral medications?

IV azithromycin 500 mg
IV or IM ampicillin 2 g
IM cefazolin 2 g or ceftriaxone 1 g (Correct answer)
IV clindamycin 600 mg

Correct answer: IM cefazolin 2 g or ceftriaxone 1 g

Current AHA guidelines recommend IM/IV cefazolin 2 g or ceftriaxone 1 g for patients who cannot take oral medications and are not allergic to penicillin.

Question 165: N95 respirators are indicated over surgical masks when performing:

Surgical extractions and implant procedures only
Routine dental examinations and prophylaxis for all patients
All dental procedures that involve contact with saliva
Aerosol-generating procedures on patients with suspected tuberculosis or airborne infections (Correct answer)

Correct answer: Aerosol-generating procedures on patients with suspected tuberculosis or airborne infections

N95 respirators, filtering 95% of airborne particles, are required during aerosol-generating procedures on patients with suspected or confirmed airborne infections such as tuberculosis.

Question 166: The paralleling technique for periapical radiographs requires the film or sensor to be placed:

Parallel to the long axis of the teeth with the central ray perpendicular (Correct answer)
As close to the teeth as possible
At a 45-degree angle to the occlusal plane
Against the lingual surface of the teeth

Correct answer: Parallel to the long axis of the teeth with the central ray perpendicular

The paralleling technique positions the receptor parallel to the tooth's long axis with the X-ray beam directed perpendicular to both.

Question 167: When calculating the sensitivity of a diagnostic test for periodontitis, which value represents the percentage of people WITH the disease who test positive?

True negative / (True negative + False negative) × 100
True negative / (True negative + False positive) × 100
True positive / (True positive + False negative) × 100 (Correct answer)
True positive / (True positive + False positive) × 100

Correct answer: True positive / (True positive + False negative) × 100

Sensitivity = TP / (TP + FN) × 100 — the proportion of diseased patients correctly identified as positive; high sensitivity minimizes false negatives.

Question 168: Injury to the hypoglossal nerve (CN XII) would cause the tongue to deviate toward which side upon protrusion?

Superiorly
Contralateral to the injury
Ipsilateral to the injury (Correct answer)
No deviation occurs

Correct answer: Ipsilateral to the injury

The tongue deviates toward the side of injury because the intact genioglossus on the opposite side pushes the tongue toward the weakened side.

Question 169: Which oral lesion is described as a white patch that cannot be wiped off and carries a risk of malignant transformation?

Candidiasis
Fibroma
Leukoplakia (Correct answer)
Aphthous ulcer

Correct answer: Leukoplakia

Leukoplakia is a white patch that cannot be scraped off and has a recognized risk of malignant transformation.

Question 170: A panoramic radiograph of a 14-year-old patient reveals a well-defined, corticated radiolucency inferior to the mandibular canal in the left posterior mandible. The patient is asymptomatic. Which of the following is the MOST likely interpretation?

A periapical cyst associated with the first molar.
Evidence of localized osteomyelitis.
A normal anatomical variation, such as a Stafne bone defect. (Correct answer)
An early-stage benign tumor.

Correct answer: A normal anatomical variation, such as a Stafne bone defect.

A Stafne bone defect (also known as a static bone cyst or lingual mandibular bone depression) is an asymptomatic, well-defined radiolucency typically located below the mandibular canal. It represents a depression on the lingual aspect of the mandible where salivary gland tissue is located and is considered a normal anatomical variation.

Question 171: When assessing a patient's blood pressure and finding 178/95 mmHg at the beginning of an appointment, the dental hygienist's BEST initial action is:

Cancel the appointment without further assessment
Proceed with treatment using only topical anesthetic to avoid any systemic effects
Measure blood pressure in the opposite arm, allow patient to rest 5 minutes, and remeasure before consulting the dentist (Correct answer)
Immediately administer nitroglycerin

Correct answer: Measure blood pressure in the opposite arm, allow patient to rest 5 minutes, and remeasure before consulting the dentist

A reading of 178/95 approaches hypertensive crisis; the appropriate initial response is to recheck with proper technique (opposite arm, rest period) to confirm accuracy before canceling treatment or referring.

Question 172: Which oral lesion is described as a dome-shaped, fluctuant blue swelling of the floor of the mouth resulting from a ruptured salivary gland duct?

Dermoid cyst
Ranula (Correct answer)
Mucocele
Lymphoepithelial cyst

Correct answer: Ranula

A ranula is a mucous retention phenomenon of the sublingual gland that presents as a translucent blue swelling on the floor of the mouth.

Question 173: Kaposi's sarcoma in the oral cavity appears most frequently on which structure?

Lateral tongue
Hard palate and gingiva (Correct answer)
Buccal mucosa
Floor of mouth

Correct answer: Hard palate and gingiva

Oral Kaposi's sarcoma, associated with HHV-8 in immunocompromised patients, most commonly presents as a red-purple lesion on the hard palate and gingiva.

Question 174: Which of the following community-based programs is the BEST example of primary prevention in oral health?

Community water fluoridation. (Correct answer)
Providing dentures for residents of a long-term care facility.
A mobile dental van providing restorative fillings.
An oral cancer screening event at a local health fair.

Correct answer: Community water fluoridation.

Primary prevention aims to prevent disease before it occurs. Community water fluoridation is a population-wide measure that prevents dental caries from developing. Screenings are secondary prevention (early detection), while providing fillings and dentures are examples of tertiary prevention (restoring function and limiting disability from existing disease).

Question 175: Which type of elastomeric impression material requires the use of a custom or stock tray with adhesive AND has the longest setting time among elastomers?

Polysulfide (mercaptan) (Correct answer)
Polyether
Addition silicone (PVS)
Condensation silicone

Correct answer: Polysulfide (mercaptan)

Polysulfide (mercaptan) impression materials have the longest setting time of all elastomers, require an adhesive for tray retention, and must be poured promptly due to poor dimensional stability.

Question 176: Sensitivity of a screening test refers to its ability to:

Measure disease severity
Correctly identify those with the disease (Correct answer)
Predict future disease risk
Correctly identify those without the disease

Correct answer: Correctly identify those with the disease

Sensitivity is the proportion of true positives correctly identified (true positive rate) among all diseased individuals.

Question 177: A patient reports severe anxiety about dental treatment and requests 'something to calm them down.' The drug diazepam (Valium) belongs to which drug class, and what is its mechanism of action?

Opioid — binds mu receptors to produce sedation
Antihistamine — blocks H1 receptors causing sedation
Benzodiazepine — positive allosteric modulator of GABA-A receptors, increasing chloride ion conductance and producing CNS depression (Correct answer)
Barbiturate — directly opens chloride channels

Correct answer: Benzodiazepine — positive allosteric modulator of GABA-A receptors, increasing chloride ion conductance and producing CNS depression

Diazepam is a benzodiazepine that enhances GABA-A receptor activity by binding at the benzodiazepine site, increasing the frequency of chloride channel opening, hyperpolarizing neurons, and producing anxiolysis and sedation.

Question 178: The latent image on conventional radiographic film is formed by:

Interaction of X-ray photons with silver halide crystals in the emulsion (Correct answer)
Ionization of the polyester film base
Direct exposure of the film emulsion to visible light
Chemical development of the gelatin base

Correct answer: Interaction of X-ray photons with silver halide crystals in the emulsion

X-ray photons interact with silver halide crystals in the film emulsion, liberating electrons that reduce silver ions and form a latent (invisible) image.

Question 179: Which dental hygienist and educator is recognized for developing the theory of 'Dental Hygienist as Primary Oral Health Care Provider'?

G.V. Black in the 1900s
Joan Otomo-Corgel and the ADHA, who published the 'Dental Hygiene Diagnosis' and 'Direct Access' positions papers advancing independent practice (Correct answer)
Esther Wilkins in her 1959 textbook only
Pierre Fauchard in his 1728 work

Correct answer: Joan Otomo-Corgel and the ADHA, who published the 'Dental Hygiene Diagnosis' and 'Direct Access' positions papers advancing independent practice

The ADHA's position papers and advocates including Otomo-Corgel advanced dental hygiene diagnosis, direct access, and independent practice — positioning DHs as primary oral health care providers.

Question 180: What is the main disadvantage of resin-modified glass ionomer cement (RMGI) compared to conventional glass ionomer when used as a base?

Inferior fluoride release over time
Lower biocompatibility near the pulp
Hygroscopic expansion that can fracture all-ceramic restorations (Correct answer)
Inability to bond chemically to tooth structure

Correct answer: Hygroscopic expansion that can fracture all-ceramic restorations

RMGI absorbs water and expands hygroscopically after setting, which can generate stresses sufficient to crack brittle all-ceramic restorations placed over them.

Question 181: The DMFT index records:

Plaque accumulation on all surfaces
Probing depth and attachment loss
Fluorosis severity on enamel
Decayed, missing, and filled permanent teeth (Correct answer)

Correct answer: Decayed, missing, and filled permanent teeth

The DMFT index is an epidemiological measure of lifetime caries experience, counting decayed, missing, and filled permanent teeth.

Question 182: Nitrous oxide-oxygen sedation (N2O/O2) used in dental hygiene is classified as which level of sedation?

General anesthesia — patient unconscious
Minimal sedation (anxiolysis) — patient fully conscious and responsive (Correct answer)
Moderate sedation (conscious sedation) — patient depressed but arousable
Deep sedation — patient barely arousable

Correct answer: Minimal sedation (anxiolysis) — patient fully conscious and responsive

At the concentrations used in dentistry (up to 50% N2O), nitrous oxide provides minimal sedation (anxiolysis) only — the patient remains fully conscious, maintains their own airway, and responds normally to verbal communication.

Question 183: During a periodontal assessment of a multi-rooted tooth, the dental hygienist can detect the furcation with a Nabers probe, but it does not pass completely through. The bone between the roots is intact, allowing only partial penetration. According to Glickman's classification, this is classified as:

Class IV Furcation
Class II Furcation (Correct answer)
Class I Furcation
Class III Furcation

Correct answer: Class II Furcation

Glickman's classification describes a Class II furcation as a lesion where the probe can enter the furcation area but cannot pass through to the other side because a portion of the alveolar bone and periodontal ligament remains intact.

Question 184: In mass fluoride supplementation, the term 'herd effect' refers to:

Community-wide dietary fluoride consumption
Individual benefit from collective exposure reduction
Livestock receiving fluoride through farm water
Protection of non-recipients due to reduced disease transmission (Correct answer)

Correct answer: Protection of non-recipients due to reduced disease transmission

While primarily used for infectious disease, in fluoridation contexts 'herd effect' broadly means non-recipients benefit from community-wide reductions in disease burden.

Question 185: What is the titanium object that appears like a tooth and is used?

Plaque
Dental implant (Correct answer)
Fling
Fluoride

Correct answer: Dental implant

A dental implant is a titanium post, shaped like a tooth root, that is surgically placed into the jawbone beneath the gum line. Titanium is biocompatible, allowing the implant to fuse with the bone in a process called osseointegration. This creates a stable and durable foundation for a replacement tooth, bridge, or denture, effectively mimicking the function and appearance of a natural tooth root.

Question 186: Which systemic condition is most strongly associated with increased susceptibility to periodontitis and impaired healing?

Iron-deficiency anemia
Hypertension
Hypothyroidism
Uncontrolled type 2 diabetes mellitus (Correct answer)

Correct answer: Uncontrolled type 2 diabetes mellitus

Uncontrolled diabetes impairs neutrophil function and wound healing, significantly increasing susceptibility to and severity of periodontitis.

Question 187: The radiopaque line that represents the floor of the maxillary sinus on a periapical radiograph is known as the:

Nasal septum
Hard palate
Cortical boundary of the maxillary sinus (Correct answer)
Zygomatic process of the maxilla

Correct answer: Cortical boundary of the maxillary sinus

The cortical boundary of the maxillary sinus floor appears as a thin radiopaque line superimposed over the maxillary molar roots.

Question 188: What is the purpose of the 'sand blasting' (air abrasion) step when bonding to metal surfaces of a PFM restoration?

To increase the metal's corrosion resistance
To apply a silane coupling agent
To reduce the surface hardness for better bonding
To remove the oxide layer and increase micromechanical retention (Correct answer)

Correct answer: To remove the oxide layer and increase micromechanical retention

Air abrasion with aluminum oxide removes surface contaminants and creates micromechanical retention by roughening the metal surface prior to bonding.

Question 189: A patient with epilepsy is taking phenytoin (Dilantin). Which oral manifestation is most commonly associated with long-term use of this medication?

Oral candidiasis
Hairy tongue
Gingival hyperplasia (Correct answer)
Angular cheilitis

Correct answer: Gingival hyperplasia

Phenytoin-induced gingival hyperplasia is a well-documented side effect, occurring in up to 50% of patients, especially with poor plaque control.

Question 190: Silver diamine fluoride (SDF) is used in caries management primarily for which purpose?

Treating dentinal hypersensitivity only
Whitening discolored dentin
Arresting active carious lesions without drilling (Correct answer)
Replacing traditional fluoride varnish in all patients

Correct answer: Arresting active carious lesions without drilling

SDF arrests active caries by killing cariogenic bacteria and hardening demineralized dentin, making it ideal for high-risk or medically complex patients.

Question 191: When selecting a shade for a ceramic restoration, at what time of day and under what light should shade matching ideally be performed?

After rubber dam placement under the dental curing light
During try-in under the patient's home lighting conditions
Late afternoon under fluorescent operatory lights
Early in the appointment under natural daylight or balanced daylight bulbs (Correct answer)

Correct answer: Early in the appointment under natural daylight or balanced daylight bulbs

Shade matching should be done early before the patient's teeth dehydrate and lighten, using natural daylight or a balanced color-corrected light source to avoid metamerism.

Question 192: An elderly patient with Alzheimer's disease presents with increased plaque accumulation and root caries. The MOST effective oral hygiene strategy involves:

Relying on chlorhexidine rinse alone
Teaching the patient complex multi-step oral hygiene techniques
Recommending dental extractions to simplify care
Training and involving the caregiver in daily oral hygiene, using fluoride varnish applications, and simplified hygiene tools (Correct answer)

Correct answer: Training and involving the caregiver in daily oral hygiene, using fluoride varnish applications, and simplified hygiene tools

As cognitive decline progresses, caregivers become essential partners; using high-fluoride applications, simplified tools (electric toothbrush), and caregiver training provides the most practical and effective oral care.

Question 193: Secondary prevention in dentistry is best illustrated by:

Nutritional counseling to reduce sugar intake
Community water fluoridation
Early detection and treatment of incipient gingivitis (Correct answer)
Application of pit and fissure sealants

Correct answer: Early detection and treatment of incipient gingivitis

Secondary prevention involves early disease detection and intervention to halt progression, such as identifying and treating early gingivitis before it advances to periodontitis.

Question 194: The long-term retention of a pit and fissure sealant is MOST dependent on which of the following steps during its application?

Meticulous isolation to maintain a dry field (Correct answer)
Applying a fluoride varnish immediately prior to etching
Using air-powder polishing to prepare the enamel surface
Curing the sealant material for a minimum of 60 seconds

Correct answer: Meticulous isolation to maintain a dry field

The success of a sealant relies on the micromechanical bond created between the resin and the etched enamel. Any contamination of the etched surface by saliva or moisture will interfere with the formation of resin tags and prevent a proper bond, leading to premature sealant failure. Therefore, maintaining a completely dry field is the single most critical factor for long-term retention.

Question 195: A patient taking warfarin requires scaling and root planing. The INR is 3.8. What is the most appropriate action?

Proceed with full-mouth debridement
Administer local anesthetic without a vasoconstrictor
Use only hand instruments to minimize bleeding
Consult the patient's physician before treatment (Correct answer)

Correct answer: Consult the patient's physician before treatment

An INR above 3.5 indicates excessive anticoagulation; physician consultation is required before invasive periodontal procedures.

Question 196: A 'herringbone' or 'tire track' pattern artifact appears on a processed dental radiograph. This artifact is MOST likely caused by:

Excessive bending of the film during placement
Placing the film in the mouth with the lead foil side facing the x-ray source (Correct answer)
Contamination of the developer with fixer solution
Overdevelopment in the developer solution

Correct answer: Placing the film in the mouth with the lead foil side facing the x-ray source

When a periapical film is placed backwards (lead foil side toward the tube), the x-ray beam passes through the foil before reaching the emulsion, creating a faint herringbone or tire-track pattern from the embossed lead foil backing. This also results in a significantly underexposed, lighter-than-normal image.

Question 197: A dental hygienist who performs a procedure that they are not legally authorized to perform in their state may be charged with:

Practicing dentistry without a license (unauthorized practice of dentistry) (Correct answer)
No violation if the dentist asked them to perform it
Battery only if the patient was injured
Only civil negligence

Correct answer: Practicing dentistry without a license (unauthorized practice of dentistry)

Performing procedures beyond the dental hygienist's legal scope of practice — regardless of dentist authorization — constitutes unauthorized practice of dentistry, which is a criminal offense in all states.

Question 198: A dental hygienist receives a subpoena for a patient's dental records in connection with a personal injury lawsuit. The hygienist should:

Provide the records as required by law after notifying the patient if permitted (Correct answer)
Release only a summary of the records rather than the originals
Refuse to release records because HIPAA prohibits any disclosure without patient consent
Destroy the records to protect the patient's privacy

Correct answer: Provide the records as required by law after notifying the patient if permitted

A valid subpoena is a court order that constitutes a legal basis for disclosure under HIPAA. The hygienist should comply with the subpoena, notify the patient when feasible, and provide complete, unaltered records as requested.

Question 199: Which organism is the primary causative agent of acute necrotizing ulcerative gingivitis (ANUG)?

Fusobacterium nucleatum and Treponema species (Correct answer)
Porphyromonas gingivalis only
Actinomyces israelii
Streptococcus mutans and Lactobacillus

Correct answer: Fusobacterium nucleatum and Treponema species

ANUG is associated with a fusospirochetal complex, primarily Fusobacterium nucleatum and Treponema species, in a setting of stress and immune compromise.

Question 200: A patient reports taking St. John's Wort as an herbal supplement. Which drug interaction is most clinically relevant in dental hygiene care?

It increases the anticoagulant effect of warfarin
It reduces the efficacy of oral contraceptives and many prescription medications via CYP450 induction (Correct answer)
It potentiates the effects of local anesthetics
It causes gingival hyperplasia similar to cyclosporine

Correct answer: It reduces the efficacy of oral contraceptives and many prescription medications via CYP450 induction

St. John's Wort is a potent CYP450 inducer that accelerates metabolism of many drugs including oral contraceptives, antiretrovirals, and warfarin, reducing their effectiveness.

Question 201: The role of the dental hygienist during a medical emergency in the dental office is to:

Administer all emergency medications without dentist guidance
Step aside and let only the dentist manage all emergencies
Provide basic life support (BLS), assist the dentist, call emergency services (911), and manage the emergency within their training until EMS arrives (Correct answer)
Only record what happened and call the patient's physician

Correct answer: Provide basic life support (BLS), assist the dentist, call emergency services (911), and manage the emergency within their training until EMS arrives

All dental team members must be trained in BLS/CPR; the DH activates EMS, assists with emergency medications, performs CPR, uses the AED, and supports the dentist throughout the emergency.

Question 202: Which dental alloy classification contains at least 25% gold and is used for crowns requiring high strength?

Type IV (Correct answer)
Type I
Type III
Type II

Correct answer: Type IV

Type IV gold alloy has the highest hardness and strength due to its composition, making it suitable for thin restorations like inlays, partial denture frameworks, and clasps.

Question 203: Pemphigus vulgaris is an autoimmune condition characterized by a positive Nikolsky sign and:

Subepithelial blisters
Granulomatous inflammation
White Wickham's striae
Intraepithelial flaccid bullae that rupture easily (Correct answer)

Correct answer: Intraepithelial flaccid bullae that rupture easily

Pemphigus vulgaris involves IgG autoantibodies against desmoglein proteins, causing intraepithelial acantholysis and flaccid bullae that rupture to form painful erosions.

Question 204: A dental hygienist is evaluating a set of bitewing radiographs. The images show significant overlapping of the interproximal contacts, making caries detection impossible. This error is caused by incorrect:

Exposure time
Horizontal angulation (Correct answer)
Film placement
Vertical angulation

Correct answer: Horizontal angulation

Overlapping of the interproximal contacts on a bitewing radiograph is a classic sign of incorrect horizontal angulation. The central ray of the x-ray beam was not directed perpendicularly through the contact points of the teeth.

Question 205: A patient with autism spectrum disorder (ASD) is scheduled for a dental appointment. Which desensitization technique is most effective for reducing anxiety?

Administering nitrous oxide immediately
Using a tell-show-do approach with repeated pre-visit exposures (Correct answer)
Scheduling longer single appointments to complete all treatment
Providing written instructions only

Correct answer: Using a tell-show-do approach with repeated pre-visit exposures

Tell-show-do combined with repeated pre-visit exposures (desensitization visits) is the most effective behavioral approach for patients with ASD.

Question 206: All of the above methods, with the exception of ____________, are frequently used to introduce fluoride.

Mouthwash
Drinking water
Toothpaste
Injection (Correct answer)

Correct answer: Injection

Fluoride is commonly introduced to prevent dental caries through various methods, including topical applications like toothpaste and mouthwash, and systemic ingestion via fluoridated drinking water or dietary supplements. However, fluoride is not administered by injection for the purpose of preventing dental caries. Injection is not a standard or effective method for delivering fluoride to the tooth surface for caries prevention.

Question 207: A research study concludes that a new mouthrinse leads to a statistically significant reduction in plaque scores (p < 0.05). However, the average reduction was only 0.1 on a 5-point plaque index scale. This finding is BEST described as having:

Neither clinical nor statistical significance.
Low clinical significance despite being statistically significant. (Correct answer)
High clinical significance but low statistical significance.
High clinical significance and high statistical significance.

Correct answer: Low clinical significance despite being statistically significant.

Statistical significance (indicated by a low p-value) means the result is unlikely due to chance. Clinical significance refers to whether the result has a meaningful, practical impact on patient health. A very small reduction in plaque, even if statistically significant, may not be clinically meaningful for improving the patient's oral health.

Question 208: The maximum permissible dose (MPD) of ionizing radiation for an occupationally exposed dental worker per year in the U.S. is:

5 mSv (0.5 rem) per year
20 mSv (2 rem) per year
100 mSv (10 rem) per year
50 mSv (5 rem) per year (Correct answer)

Correct answer: 50 mSv (5 rem) per year

The National Council on Radiation Protection sets the MPD for occupationally exposed persons at 50 mSv (5 rem) per year, with a cumulative lifetime limit of 10 mSv × age.

Question 209: Under HIPAA, which of the following represents a permitted disclosure of protected health information without patient authorization?

Releasing information to the patient's family members without the patient's consent
Disclosing information to public health authorities for disease surveillance (Correct answer)
Providing records to the patient's insurance company for marketing purposes
Sharing records with a patient's employer upon request

Correct answer: Disclosing information to public health authorities for disease surveillance

HIPAA permits disclosure to public health authorities for activities such as disease surveillance, reporting, and control without patient authorization.

Question 210: The CAMBRA (Caries Management by Risk Assessment) model categorizes patients into risk levels to guide treatment. A patient with active white spots, high S. mutans, and low salivary flow is placed in which category?

Low risk
Moderate risk
High risk
Extreme risk (Correct answer)

Correct answer: Extreme risk

In CAMBRA, a patient with multiple risk indicators—active lesions, high bacterial load, and salivary dysfunction—is classified as extreme risk.

Question 211: What is the purpose of the smear layer in restorative dentistry, and how does acid etching affect it?

It strengthens dentin; acid etching hardens it further
It has no clinical significance; acid etching has no effect
It plugs dentinal tubules; acid etching removes it and opens tubules (Correct answer)
It prevents bacterial invasion; acid etching reinforces it

Correct answer: It plugs dentinal tubules; acid etching removes it and opens tubules

The smear layer is a thin film of debris on prepared dentin that plugs tubule openings; acid etching dissolves it and opens dentinal tubules, enabling resin tag formation.

Question 212: The standard gravity displacement autoclave operates at which temperature and duration for wrapped instruments?

320°F (160°C) for 60 minutes
212°F (100°C) for 20 minutes
250°F (121°C) for 15-30 minutes (Correct answer)
270°F (132°C) for 3-4 minutes

Correct answer: 250°F (121°C) for 15-30 minutes

Gravity displacement autoclaves operate at 121°C (250°F) at 15 psi for 15-30 minutes to achieve sterilization of wrapped instruments.

Question 213: The Bass toothbrushing technique is most effective for removing plaque from which area?

Gingival sulcus and cervical third (Correct answer)
Occlusal surfaces
Posterior lingual surfaces
Interproximal contacts

Correct answer: Gingival sulcus and cervical third

The Bass technique uses a 45-degree angulation toward the gingival sulcus with short vibratory strokes to clean the sulcular area.

Question 214: The superior orbital fissure transmits which cranial nerves?

CN II, V1, VI
CN III, IV, V1, VI (Correct answer)
CN II, III, IV
CN V1, V2, VI

Correct answer: CN III, IV, V1, VI

The superior orbital fissure transmits CN III (oculomotor), CN IV (trochlear), CN V1 (ophthalmic division), and CN VI (abducens), along with sympathetic fibers and ophthalmic veins.

Question 215: A patient with a history of substance use disorder is in recovery and taking methadone maintenance therapy. Which dental concern is most significant?

Methadone's high sugar content and xerogenic effects causing rampant caries (Correct answer)
Increased susceptibility to periodontal disease only
Increased calculus formation from salivary pH changes
Gingival overgrowth from methadone metabolism

Correct answer: Methadone's high sugar content and xerogenic effects causing rampant caries

Methadone syrup has high sugar content and causes xerostomia, creating conditions for rapidly progressing 'meth mouth' type carious lesions.

Question 216: A dental hygienist completes a prophylaxis on an adult patient. Without discussing it first, the hygienist applies a fluoride varnish, assuming the patient would want it. The patient later expresses they did not want the treatment. This action could be legally classified as which of the following?

Defamation
Negligence
Battery (Correct answer)
Abandonment

Correct answer: Battery

Battery is the intentional, unconsented touching of another person. Applying a treatment without consent, even if it is not harmful, constitutes battery because it violates the patient's right to autonomy over their own body. Negligence involves a breach of the standard of care resulting in harm, which is different from unconsented contact.

Question 217: A patient presents with white-spot lesions on smooth surfaces. What is the MOST appropriate preventive intervention?

Immediate composite restoration
Increased fluoride application and dietary counseling (Correct answer)
Fissure sealant placement
Extraction and implant planning

Correct answer: Increased fluoride application and dietary counseling

White-spot lesions are early demineralized enamel that can remineralize with fluoride therapy and dietary modification without operative intervention.

Question 218: A patient taking bisphosphonate medication for osteoporosis is considered at risk for which dental-specific complication?

Burning mouth syndrome
Medication-related osteonecrosis of the jaw (MRONJ) after invasive dental procedures (Correct answer)
Gingival hyperplasia
Rampant cervical caries

Correct answer: Medication-related osteonecrosis of the jaw (MRONJ) after invasive dental procedures

Bisphosphonates accumulate in bone and inhibit osteoclast activity; invasive dental procedures (extractions, implants) in such patients can trigger medication-related osteonecrosis of the jaw (MRONJ).

Question 219: Which of the following structures passes through the foramen ovale of the sphenoid bone?

Ophthalmic division of the trigeminal nerve (V1)
Middle meningeal artery
Mandibular division of the trigeminal nerve (V3) (Correct answer)
Maxillary division of the trigeminal nerve (V2)

Correct answer: Mandibular division of the trigeminal nerve (V3)

The mandibular division of the trigeminal nerve (V3) exits the skull through the foramen ovale. The maxillary division (V2) passes through the foramen rotundum, the ophthalmic division (V1) passes through the superior orbital fissure, and the middle meningeal artery passes through the foramen spinosum.

Question 220: A patient with Type 1 diabetes presents for a dental hygiene appointment. Which oral manifestation is MOST associated with poorly controlled diabetes?

Rampant cervical caries only
Xerostomia without periodontal involvement
White candidiasis unrelated to blood glucose levels
Severe generalized periodontitis with poor healing (Correct answer)

Correct answer: Severe generalized periodontitis with poor healing

Poorly controlled diabetes is bidirectionally linked with severe periodontitis; hyperglycemia impairs neutrophil function and healing, worsening periodontal disease, which in turn worsens glycemic control.

Question 221: Which of the following is the primary goal of root planing compared to scaling?

Remove the junctional epithelium
Establish a new connective tissue attachment
Smooth the root surface by removing cementum containing endotoxins (Correct answer)
Remove supragingival calculus deposits

Correct answer: Smooth the root surface by removing cementum containing endotoxins

Root planing removes the outermost layer of cementum embedded with calculus and bacterial endotoxins, creating a smooth, biologically compatible surface.

Question 222: A dental hygienist is counseling a pregnant patient about oral health. Which statement is MOST accurate?

Periodontal disease in pregnancy is associated with adverse birth outcomes (Correct answer)
Pregnancy itself causes tooth loss and cannot be prevented
Fluoride is contraindicated during pregnancy
Routine cleanings should be avoided in the first trimester

Correct answer: Periodontal disease in pregnancy is associated with adverse birth outcomes

Research has linked maternal periodontal disease to preterm birth and low birth weight, making prenatal periodontal care clinically important.

Question 223: Nicotinic stomatitis presents with white papules containing red centers primarily on the:

Hard palate (Correct answer)
Lateral tongue
Floor of the mouth
Buccal mucosa

Correct answer: Hard palate

Nicotinic stomatitis develops on the hard palate of pipe smokers, with red centers representing inflamed minor salivary gland duct openings.

Question 224: During patient assessment, a probing depth of 4–6 mm with bleeding on probing and radiographic bone loss is classified as:

Periodontitis (Correct answer)
Necrotizing periodontal disease
Gingivitis
Healthy periodontium

Correct answer: Periodontitis

Periodontitis is characterized by probing depths exceeding 3 mm accompanied by clinical attachment loss, radiographic bone loss, and bleeding on probing. Gingivitis involves inflammation without attachment or bone loss, while a healthy periodontium shows neither inflammation nor bone loss.

Question 225: Cone-beam computed tomography (CBCT) is preferred over conventional radiography for which specific clinical application in dental hygiene practice?

Assessment of alveolar bone morphology and furcation defects in complex periodontal cases (Correct answer)
Routine caries detection in bitewing surveys
Screening for osteoporosis
Evaluating enamel integrity in Class V lesions

Correct answer: Assessment of alveolar bone morphology and furcation defects in complex periodontal cases

CBCT provides three-dimensional visualization of alveolar bone, enabling precise assessment of bone defect morphology, furcation involvement, and root proximity that conventional 2D radiography cannot fully depict.

Question 226: Which instrument is best suited for removing calculus from the furcation area of a mandibular first molar?

Columbia 13/14 curette
Gracey 11/12 curette
Langer 1/2 curette (Correct answer)
Nabers probe

Correct answer: Langer 1/2 curette

The Langer 1/2 curette is specifically designed for furcation debridement on posterior teeth and adapts well to furcation areas.

Question 227: During periodontal re-evaluation 4–6 weeks after scaling and root planing, a site shows a pocket reduction from 6 mm to 4 mm with no bleeding on probing. What does this indicate?

The area should be re-scaled immediately
Surgical intervention is immediately required
Successful response to therapy; continue with supportive periodontal therapy (Correct answer)
Active disease is still present

Correct answer: Successful response to therapy; continue with supportive periodontal therapy

A pocket reduction to 4 mm with no bleeding on probing indicates successful healing and transition to supportive periodontal therapy is appropriate.

Question 228: Which film speed classification requires the LEAST exposure time (lowest radiation dose) to produce a diagnostically acceptable periapical radiograph?

F-speed (Insight) (Correct answer)
E-speed (Ektaspeed)
C-speed
D-speed (Ultraspeed)

Correct answer: F-speed (Insight)

F-speed film (e.g., Kodak Insight) is the fastest conventional film available and requires approximately 20% less exposure than E-speed and 60% less than D-speed. Faster film requires fewer x-ray photons to produce an image, directly reducing patient dose. The trade-off is a very slight increase in grain, though F-speed images remain diagnostically acceptable.

Question 229: During active periodontal debridement with a hand curette, the correct working angulation of the blade face against the tooth surface is:

45 to 90 degrees (Correct answer)
20 to 40 degrees
0 to 20 degrees
90 to 110 degrees

Correct answer: 45 to 90 degrees

A working angulation of 45–90 degrees (optimally 60–80 degrees) allows the curette blade to engage calculus with sufficient lateral pressure for effective removal; angles below 45 degrees cause the blade to slide over deposits, while angles above 90 degrees dig into the cementum.

Question 230: Dental sealants are an example of which type of preventive measure?

Disability limitation
Health promotion
Early diagnosis
Specific protection (Correct answer)

Correct answer: Specific protection

Sealants are a specific protection measure—they physically block the occlusal pits and fissures to prevent caries initiation.

Question 231: What field of expertise does an orthodontist have?

Your Gums
Your Bite And Smile (Correct answer)
Children's Teeth
Root Canals

Correct answer: Your Bite And Smile

An orthodontist specializes in the diagnosis, prevention, and treatment of dental and facial irregularities, primarily focusing on malocclusions (misaligned teeth and jaws). Their expertise lies in correcting bite problems and improving the alignment of teeth to enhance both oral function and the aesthetic appearance of a patient's smile. This often involves the use of braces, aligners, and other corrective appliances.

Question 232: A patient taking lisinopril for hypertension requires a recommendation for an over-the-counter analgesic following a scaling and root planing procedure. Which of the following is the MOST appropriate recommendation?

Aspirin
Naproxen
Ibuprofen
Acetaminophen (Correct answer)

Correct answer: Acetaminophen

Acetaminophen is the most appropriate choice because it does not significantly interfere with the antihypertensive effects of ACE inhibitors like lisinopril. NSAIDs, such as ibuprofen, naproxen, and aspirin, can reduce the effectiveness of ACE inhibitors and increase the risk of acute kidney injury when used concurrently. [1, 7, 12, 15, 23]

Question 233: One of the main causes of a root canal is which of the following?

The pulp can't be fixed (Correct answer)
A cavity is present
Tooth is cracked
Gums are bleeding

Correct answer: The pulp can't be fixed

A root canal is performed when the dental pulp, the soft tissue inside the tooth containing nerves and blood vessels, becomes irreversibly inflamed or infected. If the pulp is severely damaged and cannot heal on its own, it must be removed to prevent further infection and save the tooth. While issues like a cracked tooth or deep cavity can lead to pulp damage, the ultimate reason for a root canal is the irreversible and irreparable state of the pulp.

Question 234: Which bone forms the posterior portion of the hard palate?

Maxilla
Palatine bone (Correct answer)
Sphenoid bone
Vomer

Correct answer: Palatine bone

The horizontal plates of the palatine bones form the posterior one-third of the hard palate, while the palatine processes of the maxillae form the anterior two-thirds.

Question 235: A patient reports sensitivity after placement of a resin composite in a Class II preparation. Which procedural step most likely prevented adequate hybrid layer formation?

Applying too many coats of the bonding agent
Over-drying the etched dentin, causing dentin collapse (Correct answer)
Using a self-cure activator with a light-cure adhesive
Extending the acid etch time on enamel beyond 30 seconds

Correct answer: Over-drying the etched dentin, causing dentin collapse

Over-drying etched dentin collapses the collagen fibril network, preventing resin monomer penetration and resulting in an incomplete hybrid layer with residual sensitivity.

Question 236: Which instrument design feature makes a curette different from a sickle scaler?

Curettes have two cutting edges; sickle scalers have one
Curettes have a 90-degree face angle; sickles have a 70-degree angle
Curettes have a rounded back and toe; sickle scalers have a pointed back and toe (Correct answer)
Curettes are used only supragingivally; sickles are used subgingivally

Correct answer: Curettes have a rounded back and toe; sickle scalers have a pointed back and toe

Curettes have a rounded back and rounded toe, making them safe for subgingival use, whereas sickle scalers have a pointed toe and triangular cross-section.

Question 237: A patient who has been injured by a dental hygienist's negligent scaling procedure has how long to bring a civil lawsuit, under most state laws?

Within the statute of limitations, typically 2–3 years from the date of injury or discovery (Correct answer)
There is no time limit for dental malpractice
Within 10 years, consistent across all states
Within 90 days of the injury

Correct answer: Within the statute of limitations, typically 2–3 years from the date of injury or discovery

Most states set the statute of limitations for dental malpractice at 2–3 years from the date the injury occurred or was discovered (the 'discovery rule'), though variation exists across jurisdictions.

Question 238: Fordyce spots found on the buccal mucosa and lips are:

Ectopic sebaceous glands (Correct answer)
Lymphoid aggregates
Minor salivary glands seen through mucosa
Viral papules

Correct answer: Ectopic sebaceous glands

Fordyce spots are ectopic sebaceous glands that appear as small yellow-white papules and are a normal anatomic variant requiring no treatment.

Question 239: A positive predictive value (PPV) is most affected by:

The skill of the examiner
The test's sensitivity
The test's specificity
The prevalence of disease in the population tested (Correct answer)

Correct answer: The prevalence of disease in the population tested

PPV rises when disease prevalence is higher; even a highly sensitive test has low PPV in low-prevalence populations.

Question 240: Which cell type is primarily responsible for alveolar bone resorption in periodontitis?

Neutrophil directly
Osteoblast
Fibroblast
Osteoclast, formed from mononuclear precursors via RANKL-RANK signaling (Correct answer)

Correct answer: Osteoclast, formed from mononuclear precursors via RANKL-RANK signaling

Osteoclasts are the multinucleated bone-resorbing cells; their formation from monocyte/macrophage precursors is driven by RANKL-RANK signaling, which is upregulated by inflammatory cytokines in periodontitis.

Question 241: What is the primary rationale for performing a frenectomy as part of periodontal treatment?

Increase keratinized gingiva width
Correct a gummy smile
Eliminate a frenum pull that impedes oral hygiene or causes gingival recession (Correct answer)
Reduce pocket depth in anterior regions

Correct answer: Eliminate a frenum pull that impedes oral hygiene or causes gingival recession

A frenectomy is indicated when frenum attachment causes tissue pull that compromises oral hygiene access or contributes to gingival recession.

Question 242: A radiolucent lesion associated with the crown of an unerupted tooth is most likely a:

Primordial cyst
Residual cyst
Dentigerous cyst (Correct answer)
Radicular cyst

Correct answer: Dentigerous cyst

Dentigerous (follicular) cysts form by expansion of the follicular space around the crown of an unerupted tooth.

Question 243: A patient on bisphosphonate therapy (oral, 5 years) requires oral hygiene instruction. Which complication should the clinician be most concerned with when treating this patient?

Increased risk of periodontal abscess
Medication-related osteonecrosis of the jaw (MRONJ) (Correct answer)
Dry socket following extractions only
Excessive bleeding during probing

Correct answer: Medication-related osteonecrosis of the jaw (MRONJ)

MRONJ is a serious complication associated with bisphosphonate therapy, particularly with invasive procedures or poorly healing oral tissues.

Question 244: Smoking affects periodontal disease primarily by causing which of the following?

Increased salivary flow reducing bacterial colonization
Vasoconstriction masking clinical signs and impairing neutrophil function (Correct answer)
Increased gingival bleeding and inflammation
Accelerated bone regeneration after treatment

Correct answer: Vasoconstriction masking clinical signs and impairing neutrophil function

Nicotine causes vasoconstriction that masks bleeding on probing, while also impairing neutrophil chemotaxis and phagocytosis, reducing the host's ability to fight infection.

Question 245: Which bony landmark of the skull is the attachment site for the masseter muscle?

Temporal fossa and coronoid process only
Zygomatic arch and lateral surface of the ramus and coronoid process of the mandible (Correct answer)
Pterygoid fossa and medial surface of the ramus
Mastoid process and hyoid bone

Correct answer: Zygomatic arch and lateral surface of the ramus and coronoid process of the mandible

The masseter originates from the zygomatic arch and inserts on the lateral surface of the ramus and angle of the mandible, with some fibers extending to the coronoid process.

Question 246: Which ethical principle obligates dental hygienists to provide care that is beneficial to the patient and promotes their well-being?

Nonmaleficence
Beneficence (Correct answer)
Autonomy
Justice

Correct answer: Beneficence

Beneficence is the ethical principle that requires practitioners to act in the best interest of the patient and promote their welfare.

Question 247: Which property of amalgam restorations is responsible for the initial poor marginal seal shortly after placement?

Excessive plasticity
Immediate galvanic corrosion
Dimensional change — initial contraction before expansion (Correct answer)
High coefficient of thermal expansion

Correct answer: Dimensional change — initial contraction before expansion

Fresh amalgam undergoes slight contraction immediately after setting, before its later characteristic expansion, creating initial marginal gaps that may allow microleakage.

Question 248: What is the most common oral malignancy?

Squamous cell carcinoma (Correct answer)
Melanoma
Basal cell carcinoma
Adenocarcinoma

Correct answer: Squamous cell carcinoma

Squamous cell carcinoma accounts for approximately 90% of all oral cancers.

Question 249: Which muscle is responsible for elevating the soft palate during swallowing?

Tensor veli palatini
Palatoglossus
Levator veli palatini (Correct answer)
Musculus uvulae

Correct answer: Levator veli palatini

The levator veli palatini elevates the soft palate to close off the nasopharynx during swallowing, preventing nasal regurgitation.

Question 250: Which mechanism explains corticosteroid-induced osteoporosis relevant to dental implant planning?

Stimulation of parathyroid hormone secretion only
Direct inhibition of osteoclasts
Decreased intestinal calcium absorption and increased osteoclast activity (Correct answer)
Increased osteoblast activity and bone deposition

Correct answer: Decreased intestinal calcium absorption and increased osteoclast activity

Corticosteroids reduce intestinal calcium absorption, increase renal calcium excretion, and enhance osteoclast activity while suppressing osteoblasts, leading to bone loss.

Question 251: Which of the following local drug delivery agents is placed subgingivally to reduce pocket depth as an adjunct to SRP?

Doxycycline hyclate systemic tablets
Stannous fluoride gel
Minocycline microspheres (Arestin) (Correct answer)
Chlorhexidine gluconate 0.12% rinse

Correct answer: Minocycline microspheres (Arestin)

Minocycline microspheres (Arestin) are a subgingival local drug delivery system placed directly into periodontal pockets as an adjunct to scaling and root planing.

Question 252: A patient requires a temporary crown on a tooth that is sensitive and diagnosed with reversible pulpitis. The dentist needs a luting cement that will have a palliative, or soothing, effect on the pulp. Which cement is the BEST choice?

Glass ionomer cement
Zinc phosphate cement
Zinc Oxide Eugenol (ZOE) cement (Correct answer)
Resin-modified glass ionomer cement

Correct answer: Zinc Oxide Eugenol (ZOE) cement

Zinc Oxide Eugenol (ZOE) cement contains eugenol (oil of cloves), which is known for its sedative or palliative effect on the dental pulp. This property makes it an excellent choice for temporary cementation on teeth that are sensitive or have reversible pulpitis. The other cements listed do not possess this soothing quality.

Question 253: Which cranial nerve provides sensory innervation to the anterior two-thirds of the tongue?

Hypoglossal nerve (CN XII)
Lingual nerve (branch of V3 — trigeminal) (Correct answer)
Chorda tympani (branch of VII — facial)
Glossopharyngeal nerve (CN IX)

Correct answer: Lingual nerve (branch of V3 — trigeminal)

The lingual nerve (branch of the mandibular division of the trigeminal — V3) provides general somatic sensation (touch, pain, temperature) to the anterior two-thirds of the tongue.

Question 254: Which of the following describes the dental management principle of 'least restrictive environment' when treating patients with intellectual disabilities?

Requiring a legal guardian to make all decisions without patient input
Restricting treatment to emergency care only
Using the least invasive behavioral and clinical techniques that allow safe, effective treatment (Correct answer)
Always using general anesthesia for predictability

Correct answer: Using the least invasive behavioral and clinical techniques that allow safe, effective treatment

Least restrictive environment means attempting basic behavior guidance, desensitization, and protective stabilization before escalating to sedation or general anesthesia.

Question 255: Which organization is responsible for developing and administering the National Board Dental Hygiene Examination (NBDHE)?

National Institute of Dental Research (NIDR)
American Dental Hygienists' Association (ADHA)
American Dental Association (ADA)
Joint Commission on National Dental Examinations (JCNDE) (Correct answer)

Correct answer: Joint Commission on National Dental Examinations (JCNDE)

The Joint Commission on National Dental Examinations (JCNDE), an independent body sponsored by the ADA, constructs and administers the NBDHE as a standardized credentialing examination.

Question 256: A patient has xerostomia and reduced salivary flow. Which buffer system in saliva is most important for neutralizing plaque acids?

Phosphate buffer system
Bicarbonate buffer system (Correct answer)
Protein buffer system
Citrate buffer system

Correct answer: Bicarbonate buffer system

The bicarbonate buffer system is the dominant buffer in stimulated saliva, neutralizing plaque acids generated by cariogenic bacteria.

Question 257: A new salivary biomarker test for early caries detection yields 80 true negatives and 20 false positives among 100 disease-free individuals. What is the specificity of this test?

40%
60%
20%
80% (Correct answer)

Correct answer: 80%

Specificity = TN / (TN + FP) = 80 / (80 + 20) = 80%. Specificity measures how accurately a test identifies those WITHOUT disease (the true negative rate), thereby minimizing false positives and avoiding unnecessary treatment.

Question 258: Which instrument characteristic distinguishes a Gracey curette from a universal curette?

Gracey curettes are area-specific with one working cutting edge per blade, angled at 60–70° to the terminal shank; universal curettes have two cutting edges angled at 90° (Correct answer)
Gracey curettes are used only supragingivally; universal curettes are only subgingival
There is no functional difference between them
Gracey curettes have two cutting edges and are used on all surfaces; universal curettes are area-specific

Correct answer: Gracey curettes are area-specific with one working cutting edge per blade, angled at 60–70° to the terminal shank; universal curettes have two cutting edges angled at 90°

Gracey curettes are area-specific, with one functional cutting edge per working end (the lower/outer edge), designed so the face is at 60–70° to the terminal shank for proper blade adaptation subgingivally.

Question 259: The modified Stillman toothbrushing technique is specifically recommended for patients with:

Fixed orthodontic appliances
Gingival recession and exposed root surfaces (Correct answer)
Implant-supported restorations
Deep periodontal pockets

Correct answer: Gingival recession and exposed root surfaces

The modified Stillman technique combines vibratory strokes at the gingival margin with coronal sweeping strokes, making it suitable for patients with gingival recession.

Question 260: Which cranial nerve provides general somatic afferent innervation to the anterior two-thirds of the tongue?

CN V3 (Correct answer)
CN IX
CN XII
CN VII

Correct answer: CN V3

The lingual nerve, a branch of the mandibular nerve (CN V3), provides general somatic afferent (touch, pain, temperature) sensation to the anterior two-thirds of the tongue.

Question 261: A patient's prescription for an antimicrobial rinse has the instruction "Sig: 15 mL swish and spit q.i.d. p.c.". What does "q.i.d." indicate for the patient?

As needed for pain
Every 4 hours
Twice a day
Four times a day (Correct answer)

Correct answer: Four times a day

In pharmacology and prescription writing, the Latin abbreviation "q.i.d." stands for "quater in die," which translates to "four times a day." Other common abbreviations include b.i.d. (twice a day), t.i.d. (three times a day), and p.r.n. (as needed). [4, 22]

Question 262: The infraorbital foramen is located on which bone and transmits which nerve?

Frontal bone; supraorbital nerve (CN V1)
Mandible; mental nerve (CN V3)
Zygomatic bone; zygomaticofacial nerve (CN V2)
Maxilla; infraorbital nerve (CN V2) (Correct answer)

Correct answer: Maxilla; infraorbital nerve (CN V2)

The infraorbital foramen is located on the anterior surface of the maxilla, approximately 1 cm below the inferior orbital rim. It transmits the infraorbital nerve (a terminal branch of the maxillary division, CN V2) along with the infraorbital artery and vein.

Question 263: For a patient who has completed active periodontal therapy and has a confirmed history of Stage II generalized periodontitis, what is the standard recommended interval for periodontal maintenance appointments?

Every 12 months once clinical stability is achieved
Every 3–4 months throughout the patient's lifetime (Correct answer)
Every 2 months for the first year, then annually thereafter
Every 6 months, consistent with a routine recall schedule

Correct answer: Every 3–4 months throughout the patient's lifetime

Evidence-based guidelines recommend periodontal maintenance every 3–4 months for patients with a history of periodontitis, as the subgingival microbiome can re-establish pathogenic levels within approximately 9–11 weeks after professional debridement. Annual or 6-month intervals are insufficient to maintain stability in this population.

Question 264: The DMFT index counts which teeth in adults?

All 32 permanent teeth including third molars
Only posterior permanent teeth
Primary and permanent teeth combined
28 permanent teeth excluding third molars (Correct answer)

Correct answer: 28 permanent teeth excluding third molars

The standard DMFT index examines 28 permanent teeth, excluding third molars, to measure caries experience.

Question 265: The primary clinical feature that definitively distinguishes periodontitis from plaque-induced gingivitis is:

Increased probing depths greater than 3 mm
Clinical attachment loss (CAL) (Correct answer)
Radiographic evidence of calculus deposits
Presence of bleeding on probing

Correct answer: Clinical attachment loss (CAL)

Gingivitis involves gingival inflammation without attachment loss — the junctional epithelium remains at the CEJ. Periodontitis is defined by irreversible loss of clinical attachment and supporting alveolar bone. BOP and increased probing depths can occur in both conditions.

Question 266: The posterior superior alveolar nerve is a branch of which nerve?

Inferior alveolar nerve
Maxillary nerve (V2) (Correct answer)
Mandibular nerve (V3)
Greater palatine nerve

Correct answer: Maxillary nerve (V2)

The posterior superior alveolar nerve branches from the maxillary nerve (V2) before it enters the infraorbital canal, supplying maxillary molars.

Question 267: When performing periodontal probing, which technique is recommended to ensure the entire sulcus is assessed?

Taking a single measurement at the center of each facial and lingual surface
Using a 'walking' stroke in 1 mm increments (Correct answer)
Applying firm pressure to feel the bony crest
Angling the probe 45 degrees into the contact area

Correct answer: Using a 'walking' stroke in 1 mm increments

The 'walking' stroke, which involves moving the probe up and down in 1 mm increments along the entire circumference of the sulcus, is the standard technique. This method ensures that the deepest point of the pocket is detected, as the junctional epithelium is not uniform around the tooth.

Question 268: Prostaglandin E2 (PGE2) plays what role in the pathogenesis of periodontal disease?

It is a potent mediator of bone resorption, stimulating osteoclast activity and contributing to alveolar bone loss (Correct answer)
It inhibits metalloproteinases in periodontal tissues
It promotes bone formation and periodontal healing
It primarily causes the increased GCF flow seen in health

Correct answer: It is a potent mediator of bone resorption, stimulating osteoclast activity and contributing to alveolar bone loss

PGE2, produced by macrophages and fibroblasts in response to bacterial LPS and cytokines, stimulates osteoclast differentiation and activity via RANKL upregulation, driving alveolar bone destruction in periodontitis.

Question 269: The sulcular toothbrushing method, which directs bristles at a 45-degree angle into the gingival sulcus, is named after which researcher?

Clayton Gracey
Paul Keyes
Charles C. Bass (Correct answer)
Alfred Fones

Correct answer: Charles C. Bass

Dr. Charles C. Bass, a physician and parasitologist, developed the Bass technique emphasizing removal of plaque at and below the gingival margin, making it a cornerstone of oral hygiene instruction.

Question 270: While taking a panoramic radiograph, the dental hygienist instructs the patient to place their tongue against the roof of their mouth and swallow. If the patient fails to do this, what error is MOST likely to appear on the final image?

An exaggerated 'smile line' with foreshortened mandibular incisors.
Blurring and narrowing of the anterior teeth.
A radiopaque artifact resembling a 'ghost image' of the spine.
A large, dark shadow over the apices of the maxillary teeth. (Correct answer)

Correct answer: A large, dark shadow over the apices of the maxillary teeth.

If the patient's tongue is not in contact with the hard palate during a panoramic exposure, a large, radiolucent shadow (palatoglossal air space) will be superimposed over the apices of the maxillary teeth, potentially obscuring diagnostic information.

Question 271: The ALARA principle in radiography stands for:

As Low As Reasonably Achievable (Correct answer)
As Large As Radiographically Apparent
Accurate Lateral Angular Radiographic Assessment
Adjusted Low Angle Radiographic Alignment

Correct answer: As Low As Reasonably Achievable

ALARA means 'As Low As Reasonably Achievable' and guides practitioners to minimize patient radiation exposure while obtaining diagnostic quality images.

Question 272: Which structure forms the posterior wall of the submandibular triangle?

Digastric posterior belly (Correct answer)
Mylohyoid muscle
Stylohyoid muscle
Hyoglossus muscle

Correct answer: Digastric posterior belly

The posterior belly of the digastric muscle forms the posterior boundary of the submandibular triangle.

Question 273: What class of dental product includes Listerine and Scope?

Toothpaste
Floss
Toothbrush
Mouthwash (Correct answer)

Correct answer: Mouthwash

Listerine and Scope are widely recognized brands of mouthwash. Mouthwash is a liquid oral hygiene product used to rinse the mouth, typically to reduce bacteria, freshen breath, and sometimes to deliver therapeutic agents like fluoride. It is a distinct category of dental product separate from toothpaste, toothbrushes, and floss.

Question 274: A patient reports taking sildenafil for pulmonary hypertension. Which drug used in dental emergencies is absolutely contraindicated?

Nitroglycerin (Correct answer)
Epinephrine
Atropine
Diphenhydramine

Correct answer: Nitroglycerin

Nitroglycerin combined with sildenafil (a PDE-5 inhibitor) causes profound, potentially fatal hypotension.

Question 275: Fluorosis is caused by excessive fluoride intake during:

Tooth function
Tooth root formation only
Tooth exfoliation
Tooth eruption (Correct answer)

Correct answer: Tooth eruption

Dental fluorosis results from excessive fluoride exposure during tooth development and mineralization, before eruption.

Question 276: A smooth, red, painful area on the dorsal tongue caused by atrophy of filiform papillae is characteristic of which condition?

Geographic tongue
Median rhomboid glossitis (Correct answer)
Glossitis
Black hairy tongue

Correct answer: Median rhomboid glossitis

Median rhomboid glossitis presents as a smooth, erythematous, rhomboid area in the midline of the posterior dorsal tongue due to papillary atrophy.

Question 277: What is the function of eugenol in zinc oxide eugenol (ZOE) impression paste and temporary cements?

It releases fluoride for caries prevention
It acts as the liquid component that reacts with zinc oxide to form a chelate, providing obtundent (sedative) effects (Correct answer)
It provides rigidity after setting
It acts as the plasticizer to improve flexibility

Correct answer: It acts as the liquid component that reacts with zinc oxide to form a chelate, providing obtundent (sedative) effects

Eugenol reacts with zinc oxide to form zinc eugenolate (a chelate), and it also has obtundent (pulp-sedating) and antibacterial properties beneficial for temporary restorations.

Question 278: Which bacterium is the primary etiologic agent of early childhood caries?

Actinomyces viscosus
Streptococcus mutans (Correct answer)
Porphyromonas gingivalis
Lactobacillus acidophilus

Correct answer: Streptococcus mutans

Streptococcus mutans is the principal pathogen in early childhood caries due to its acidogenicity and ability to colonize smooth surfaces.

Question 279: Which systemic condition is most strongly associated with necrotizing periodontal diseases (NPD)?

Cardiovascular disease
Type 2 diabetes mellitus
HIV infection/immunosuppression and malnutrition/stress (Correct answer)
Osteoporosis

Correct answer: HIV infection/immunosuppression and malnutrition/stress

Necrotizing periodontal diseases (NUG, NUP, necrotizing stomatitis) are strongly associated with HIV infection and other immunosuppressive states, as well as severe malnutrition and stress.

Question 280: Which ethical principle requires the dental hygienist to tell the truth and provide accurate information to patients?

Justice
Autonomy
Beneficence
Veracity (Correct answer)

Correct answer: Veracity

Veracity is the ethical principle of truthfulness — dental hygienists have a duty to provide accurate, complete, and honest information to patients regarding diagnosis, prognosis, and treatment options.

Question 281: What distinguishes a Type IV gypsum product (die stone) from a Type III gypsum (dental stone) in laboratory use?

Type IV has a higher water-to-powder ratio, making it easier to mix
Type IV contains calcium sulfate hemihydrate instead of dihydrate
Type IV sets faster but with less dimensional accuracy
Type IV has lower expansion and greater compressive strength, making it suitable for dies (Correct answer)

Correct answer: Type IV has lower expansion and greater compressive strength, making it suitable for dies

Type IV die stone has reduced setting expansion and higher compressive strength compared to Type III stone. These properties are critical for accurate dies used in fabricating cast restorations, where even minor dimensional changes would result in ill-fitting prostheses.

Question 282: The Silness and Löe plaque index scores plaque based on:

Percentage of tooth surface covered by plaque
Number of surfaces with visible plaque
Thickness of plaque at the gingival margin (Correct answer)
Color and maturity of plaque

Correct answer: Thickness of plaque at the gingival margin

The Silness and Löe plaque index uses a 0–3 scale based on the thickness of plaque at the gingival margin, detected by running a probe along the tooth surface.

Question 283: The primary purpose of the lead apron with thyroid collar in dental radiography is to:

Prevent secondary radiation from the film/sensor
Reduce primary beam exposure at the source
Minimize patient movement during exposure
Protect radiosensitive tissues — gonads and thyroid — from scatter radiation (Correct answer)

Correct answer: Protect radiosensitive tissues — gonads and thyroid — from scatter radiation

The lead apron shields the gonads and body from scattered radiation, while the thyroid collar specifically protects the thyroid gland, which is radiosensitive, especially in children and young adults.

Question 284: Tetracycline and its derivatives are contraindicated in children under age 8 primarily because they cause:

Gingival hyperplasia and delayed eruption
Increased susceptibility to early childhood caries
Permanent intrinsic discoloration of developing teeth (Correct answer)
Enamel hypoplasia limited to primary dentition

Correct answer: Permanent intrinsic discoloration of developing teeth

Tetracyclines chelate calcium ions and are incorporated into mineralizing tooth structure, producing permanent yellow-gray-brown intrinsic staining in teeth that are still developing (up to approximately age 8). This affects both primary and permanent dentition depending on the child's age.

Question 285: What is 'biologic width' and why is it clinically significant in restorative dentistry?

The distance from the CEJ to the mucogingival junction
The minimum amount of keratinized gingiva needed for implant stability
The combined dimension of junctional epithelium and connective tissue attachment, which must not be violated by restorative margins (Correct answer)
The distance between the contact point and the alveolar crest, important for papilla preservation

Correct answer: The combined dimension of junctional epithelium and connective tissue attachment, which must not be violated by restorative margins

Biologic width (~2 mm) is the combined height of junctional epithelium (~1 mm) and supracrestal connective tissue (~1 mm); placing restorative margins within it causes chronic inflammation and bone loss.

Question 286: On a periapical radiograph, a radiolucent halo around the apex of a non-vital tooth most likely represents:

External root resorption
Periapical abscess or granuloma (Correct answer)
Periapical cemento-osseous dysplasia
Condensing osteitis

Correct answer: Periapical abscess or granuloma

A periapical radiolucency around a non-vital tooth typically indicates a periapical abscess, granuloma, or cyst.

Question 287: Mouthwashes only provide short-term relief, and frequent usage can harm oral tissue.

False
True (Correct answer)

Correct answer: True

While mouthwashes can provide temporary relief from certain oral symptoms, frequent or prolonged use of some formulations can have adverse effects. Certain ingredients, such as high alcohol content or strong antimicrobials, can irritate oral tissues, disrupt the natural oral microbiome, or mask underlying oral health issues without providing a long-term solution. Therefore, it is true that mouthwashes only offer short-term relief and frequent usage can potentially harm oral tissue.

Question 288: Oral Kaposi's sarcoma most commonly presents on the palate and is strongly associated with:

Heavy tobacco use
Epstein-Barr virus alone
HIV/AIDS (Correct answer)
Candida infection

Correct answer: HIV/AIDS

Oral Kaposi's sarcoma is an AIDS-defining malignancy appearing as red, purple, or brown macules or nodules most often on the hard palate of HIV-positive patients.

Question 289: According to the 2017 World Workshop on the Classification of Periodontal and Peri-Implant Diseases, Stage III periodontitis is characterized by:

Bone loss limited to the coronal third with no furcation involvement
Generalized attachment loss with severe systemic complications
Tooth loss due to periodontitis, bone loss to the middle or apical third of the root, or furcation class II or III involvement (Correct answer)
Mild bone loss with probing depths ≤4 mm

Correct answer: Tooth loss due to periodontitis, bone loss to the middle or apical third of the root, or furcation class II or III involvement

Stage III periodontitis is characterized by tooth loss attributable to periodontitis, bone loss extending to the middle or apical third of the root, and/or furcation class II or III defects, distinguishing it from less severe stages.

Question 290: The Snyder colorimetric test assesses oral health by measuring:

Buffering capacity of saliva
Cariogenic bacterial acid production potential (Correct answer)
Fluoride levels in saliva
Periodontal pocket depth

Correct answer: Cariogenic bacterial acid production potential

The Snyder test detects acid production by oral bacteria (primarily Lactobacillus) in a culture medium, reflecting cariogenic potential.

Question 291: Which locally delivered controlled-release antibiotic device is FDA-approved for adjunctive use in periodontal pockets ≥5 mm?

Systemic doxycycline only
Tetracycline fibers (removed from market)
Doxycycline hyclate 10% polymer gel (Atridox) and minocycline microspheres (Arestin) (Correct answer)
Chlorhexidine chip (Perio Chip) alone

Correct answer: Doxycycline hyclate 10% polymer gel (Atridox) and minocycline microspheres (Arestin)

Atridox (doxycycline 10% polymer gel) and Arestin (minocycline microspheres 1 mg) are the primary FDA-approved locally delivered antibiotic systems for adjunctive subgingival use in periodontal pockets.

Question 292: Which of the following best describes the American Heart Association's current recommendation regarding antibiotic prophylaxis before dental procedures for patients with prosthetic heart valves?

Prophylaxis is only required for pediatric patients with congenital heart disease
Prophylaxis is recommended before all dental procedures that involve manipulation of gingival tissue or the periapical region of teeth, or perforation of the oral mucosa (Correct answer)
Prophylaxis is no longer recommended for any cardiac condition
Prophylaxis is required for all patients with any type of heart murmur

Correct answer: Prophylaxis is recommended before all dental procedures that involve manipulation of gingival tissue or the periapical region of teeth, or perforation of the oral mucosa

The 2007 AHA guidelines recommend antibiotic prophylaxis for high-risk cardiac conditions (prosthetic valves, previous endocarditis, congenital heart defects, cardiac transplant with valvulopathy) before gingival/periapical manipulation or mucosal perforation.

Question 293: Which local anesthetic has the longest duration of action and is most appropriate for post-operative pain management after oral surgery?

Bupivacaine 0.5% (Correct answer)
Articaine 4%
Mepivacaine 3%
Lidocaine 2%

Correct answer: Bupivacaine 0.5%

Bupivacaine 0.5% provides the longest duration of action (4–9 hours pulpal, 12+ hours soft tissue) among dental local anesthetics.

Question 294: Which fluoride concentration is found in most prescription-strength fluoride toothpastes recommended for high-caries-risk patients?

1,000 ppm
2,500 ppm
1,100 ppm
5,000 ppm (Correct answer)

Correct answer: 5,000 ppm

Prescription fluoride toothpastes typically contain 5,000 ppm fluoride (1.1% sodium fluoride) for high-risk patients.

Question 295: Which of the following is considered a modifiable risk factor for periodontal disease?

Male sex
Cigarette smoking (Correct answer)
Genetic predisposition
Age

Correct answer: Cigarette smoking

Cigarette smoking is the strongest modifiable risk factor for periodontal disease; smokers have 2–7× higher risk and worse treatment outcomes than non-smokers, but cessation improves periodontal prognosis.

Question 296: A dental hygienist develops erythema and vesicles on her hands 48 hours after contact with latex gloves. This reaction is BEST classified as which type of hypersensitivity?

Type IV — T-cell–mediated delayed hypersensitivity (Correct answer)
Type II — cytotoxic antibody-mediated hypersensitivity
Type III — immune complex–mediated hypersensitivity
Type I — IgE-mediated immediate hypersensitivity

Correct answer: Type IV — T-cell–mediated delayed hypersensitivity

The 48-hour delay and contact dermatitis presentation are hallmarks of Type IV (delayed-type) hypersensitivity, mediated by sensitized CD4+ T lymphocytes rather than antibodies. Contact dermatitis to latex chemical additives follows this timeline, in contrast to Type I reactions (urticaria, anaphylaxis) triggered by latex proteins within minutes.

Question 297: When evaluating literature to support a clinical guideline on subgingival scaling frequency, which study design provides the HIGHEST level of evidence?

A cross-sectional survey of periodontists' current treatment preferences
A well-conducted cohort study following 500 patients over 5 years
A single randomized controlled trial with blinded outcome assessment
A systematic review with meta-analysis of multiple randomized controlled trials (Correct answer)

Correct answer: A systematic review with meta-analysis of multiple randomized controlled trials

The evidence hierarchy places systematic reviews with meta-analysis of RCTs at the apex because they synthesize findings across multiple high-quality trials, reducing random error, increasing statistical power, and improving generalizability. A single RCT, while strong, ranks below this pooled synthesis of the best available individual studies.

Question 298: A patient undergoing periodontal maintenance returns every 3 months. Which of the following best describes the goal of this interval?

Allow gingival tissue to fully heal between appointments
Disrupt subgingival biofilm before it matures to a pathogenic state (Correct answer)
Allow complete recolonization of subgingival flora before disruption
Prevent the need for further active periodontal therapy

Correct answer: Disrupt subgingival biofilm before it matures to a pathogenic state

The 3-month interval disrupts subgingival biofilm before it can mature and reorganize into a pathogenic community capable of causing disease recurrence.

Question 299: Which legislation mandates that states report oral health data to the CDC through the Behavioral Risk Factor Surveillance System (BRFSS)?

The Public Health Service Act
The Social Security Act
There is no federal mandate; states participate voluntarily (Correct answer)
The Patient Protection and Affordable Care Act

Correct answer: There is no federal mandate; states participate voluntarily

BRFSS is a voluntary state-based surveillance system; states choose to participate and submit oral health module data to the CDC.

Question 300: Which radiation safety device is MOST appropriate for a dental hygienist to use to monitor cumulative occupational radiation exposure?

Lead apron only
Geiger-Müller counter
Thermoluminescent dosimeter (TLD) or digital optically stimulated luminescence (OSL) badge (Correct answer)
Ionization chamber in the operatory

Correct answer: Thermoluminescent dosimeter (TLD) or digital optically stimulated luminescence (OSL) badge

TLD or OSL personnel monitoring badges worn on the torso measure cumulative radiation dose over time and are the standard method for monitoring occupational radiation exposure for dental workers.

Question 301: A community water fluoridation program is considered which level of prevention?

Primordial prevention
Primary prevention (Correct answer)
Tertiary prevention
Secondary prevention

Correct answer: Primary prevention

Water fluoridation is primary prevention because it prevents disease before it occurs in the population.

Question 302: Which type of instrument requires sterilization according to the Spaulding classification for 'critical' items?

Items that touch only intact skin
Instruments that contact mucous membranes only
Environmental surfaces in the operatory
Instruments that penetrate soft tissue or bone (Correct answer)

Correct answer: Instruments that penetrate soft tissue or bone

Critical items penetrate soft tissue or bone and must be sterile to prevent transmission of any microorganism.

Question 303: Diagnostic techniques or dental hygiene

Describe actual or potential health problems that dental hygienists are educated and licensed to treat
Classify diagnostic statements according to disease process
All of the above (Correct answer)
Address health functioning and behaviors

Correct answer: All of the above

Dental hygiene diagnostic statements are comprehensive tools that serve multiple functions in patient care. They classify health problems based on underlying disease processes, address how these problems impact a patient's overall health functioning and behaviors, and specifically describe conditions that dental hygienists are educated and licensed to treat. This holistic approach ensures that the diagnosis effectively guides appropriate and individualized dental hygiene interventions.

Question 304: Which topical anesthetic agent is available in the highest concentration for dental use and must be used cautiously to avoid systemic toxicity?

Lidocaine 5%
Tetracaine 0.5%
Prilocaine 4%
Benzocaine 20% (Correct answer)

Correct answer: Benzocaine 20%

Benzocaine is available in concentrations up to 20% for dental topical use; excessive application can cause methemoglobinemia, particularly in children and patients with G6PD deficiency.

Question 305: A patient with chronic obstructive pulmonary disease (COPD) requires dental hygiene treatment. Which modification is most important?

Positioning the patient semi-upright and minimizing use of water spray near the airway (Correct answer)
Using high-volume oxygen during the entire appointment
Scheduling only morning appointments
Avoiding use of ultrasonic scalers entirely

Correct answer: Positioning the patient semi-upright and minimizing use of water spray near the airway

Semi-upright positioning eases breathing in COPD patients, and minimizing aerosol/water spray reduces aspiration risk.

Question 306: Which type of cyst is the most common odontogenic cyst of the jaws?

Dentigerous cyst
Calcifying odontogenic cyst
Lateral periodontal cyst
Radicular cyst (Correct answer)

Correct answer: Radicular cyst

Radicular (periapical) cysts are the most common odontogenic cysts, forming from epithelial cell rests at the apex of a non-vital tooth.

Question 307: What do you bite onto to leave your bite impression, which reveals the alignment of your teeth?

Wax (Correct answer)
Plastic
Rubber
Steel

Correct answer: Wax

Dental wax is commonly used to take bite impressions, also known as occlusal registrations. The patient bites into the softened wax, which records the precise relationship between the upper and lower teeth when the jaws are closed. This impression is crucial for dentists and lab technicians to accurately assess the patient's bite alignment and jaw relationship when fabricating restorations or orthodontic appliances.

Question 308: Foreshortening of tooth images on a periapical radiograph taken with the bisecting angle technique is caused by:

Insufficient vertical angulation (too flat/shallow)
Failure to center the central ray on the film
Incorrect horizontal angulation
Excessive vertical angulation (too steep) (Correct answer)

Correct answer: Excessive vertical angulation (too steep)

In the bisecting angle technique, the central ray should be directed perpendicular to the imaginary bisector of the angle formed by the film and the long axis of the tooth. If the vertical angulation is excessive (too steep), the recorded image of the tooth is shorter than actual length — foreshortening. Insufficient vertical angulation produces the opposite error: elongation.

Question 309: Aspirin irreversibly inhibits cyclooxygenase in platelets. How long does it take for platelet function to fully recover after aspirin discontinuation?

14–21 days
7–10 days (Correct answer)
24–48 hours
3–4 days

Correct answer: 7–10 days

Since platelets are anucleate and cannot synthesize new COX, platelet function recovers only as new platelets are produced over 7–10 days (the platelet lifespan).

Question 310: Under which circumstance is a dental hygienist LEGALLY required to breach patient confidentiality?

When another dentist in the same office asks about the patient
When an insurance company requests records for claim processing
When reporting confirmed or suspected child abuse or neglect as required by mandatory reporting laws (Correct answer)
When a patient's spouse asks about the patient's treatment

Correct answer: When reporting confirmed or suspected child abuse or neglect as required by mandatory reporting laws

All 50 states have mandatory reporting laws requiring dental hygienists to report suspected or confirmed child abuse and neglect — this legal duty overrides normal confidentiality obligations.

Question 311: A dental hygienist prepares an alginate impression for a study model. Upon inspection, the final impression has a grainy, rough surface and lacks fine detail. Which of the following is the MOST likely cause of this error?

Using water that was too cold
Leaving the impression in the patient's mouth for too long
Over-spatulation of the material
Inadequate spatulation of the powder and liquid (Correct answer)

Correct answer: Inadequate spatulation of the powder and liquid

Inadequate spatulation, or undermixing, fails to properly dissolve the alginate powder into the water. This results in unreacted particles remaining in the mix, leading to a grainy texture and a weaker impression that cannot accurately capture surface details.

Question 312: Immediate-use steam sterilization (formerly called 'flash sterilization') should be used:

Routinely to save time when patient turnover is high
For implantable devices requiring fast turnaround
As a last resort for instruments dropped and needed immediately (Correct answer)
For heat-sensitive instruments requiring rapid processing

Correct answer: As a last resort for instruments dropped and needed immediately

Immediate-use steam sterilization should only be used as a last resort for dropped instruments that are urgently needed, not for routine instrument reprocessing.

Question 313: Warfarin inhibits which vitamin-dependent clotting factors?

Factors II, VII, IX, X (Correct answer)
Factors VIII, IX, XI, XII
Factors I, V, VIII, XI
Factors V, VIII, XI, XIII

Correct answer: Factors II, VII, IX, X

Warfarin blocks vitamin K epoxide reductase, impairing carboxylation of factors II, VII, IX, and X.

Question 314: A patient with a spinal cord injury at the C5 level presents for dental hygiene treatment. Which complication is a life-threatening emergency unique to this population?

Autonomic dysreflexia (Correct answer)
Muscle spasticity
Orthostatic hypotension
Phantom pain

Correct answer: Autonomic dysreflexia

Autonomic dysreflexia is a potentially fatal hypertensive emergency triggered by stimuli below the injury level, such as a full bladder or dental pain.

Question 315: Which radiographic technique minimizes the overlap of proximal surfaces on a bitewing radiograph?

Placing the receptor closer to the tongue
Increasing vertical angulation
Directing the central ray through the contact points using correct horizontal angulation (Correct answer)
Using a longer exposure time

Correct answer: Directing the central ray through the contact points using correct horizontal angulation

Correct horizontal angulation directs the X-ray beam through the interproximal contacts, preventing overlapping of adjacent tooth surfaces.

Question 316: The principle of selective polishing differs from routine polishing primarily because it:

Requires an ultrasonic handpiece instead of a rubber cup
Uses a coarser prophy paste to save time
Is performed before scaling rather than after
Targets only teeth with clinically visible extrinsic stain, preserving fluoride-rich enamel (Correct answer)

Correct answer: Targets only teeth with clinically visible extrinsic stain, preserving fluoride-rich enamel

Selective polishing avoids unnecessary abrasion by restricting rubber cup polishing to surfaces with extrinsic stain, thereby protecting the fluoride-rich outer enamel that would otherwise be abraded on clean surfaces.

Question 317: An infection originating from a mandibular first molar would MOST likely cause initial tenderness and enlargement in which group of lymph nodes?

Submandibular nodes (Correct answer)
Parotid nodes
Submental nodes
Deep cervical nodes

Correct answer: Submandibular nodes

The submandibular lymph nodes are the primary drainage site for all mandibular posterior teeth, including the first molar. The submental nodes drain the mandibular incisors and the tip of the tongue. The deep cervical nodes receive drainage from the submandibular nodes later, and the parotid nodes drain the scalp, ear, and parotid gland.

Question 318: Hepatitis B virus (HBV) is MOST notable for which environmental characteristic?

It survives on dry surfaces for only 2-3 hours
It survives only in moist blood-soaked materials
It can remain viable on dry environmental surfaces for at least 7 days (Correct answer)
It cannot survive outside a living host

Correct answer: It can remain viable on dry environmental surfaces for at least 7 days

HBV can remain viable on dry environmental surfaces for at least 7 days, demonstrating exceptional environmental stability compared to other bloodborne pathogens.

Question 319: Which mineral is primarily responsible for the calcification of calculus, and from which oral fluid is it primarily derived?

Calcium phosphate (as hydroxyapatite, brushite, and whitlockite), primarily derived from saliva for supragingival calculus and from GCF for subgingival calculus (Correct answer)
Fluorapatite from fluoride treatments only
Calcium carbonate from dietary sources
Magnesium phosphate from plaque bacteria

Correct answer: Calcium phosphate (as hydroxyapatite, brushite, and whitlockite), primarily derived from saliva for supragingival calculus and from GCF for subgingival calculus

Calculus is primarily calcium phosphate (mostly hydroxyapatite, octacalcium phosphate, brushite); supragingival calculus mineralizes from salivary calcium/phosphate, while subgingival calculus mineralizes from GCF.

Question 320: A patient discloses a history of HIV infection during their health history. The dental hygienist's legal obligation is to:

Inform all office staff so they can take extra precautions
Document HIV status in a location visible to all staff for safety purposes
Refuse to treat the patient due to infection risk
Maintain confidentiality and follow standard precautions for all patients (Correct answer)

Correct answer: Maintain confidentiality and follow standard precautions for all patients

HIV status is protected health information; the hygienist must maintain confidentiality and apply standard precautions universally, regardless of known status.

Question 321: A patient with a history of a myocardial infarction 3 months ago requires a restorative procedure. Which of the following is the primary concern when selecting a local anesthetic?

The concentration of the topical anesthetic
The gauge of the needle used for injection
Limiting the dose of the vasoconstrictor (Correct answer)
Using an amide versus an ester type anesthetic

Correct answer: Limiting the dose of the vasoconstrictor

For patients with a recent history of myocardial infarction (typically within 3-6 months), the primary concern is cardiovascular stability. Vasoconstrictors like epinephrine can increase heart rate and blood pressure. Therefore, the dose should be limited to the minimum effective amount, often the cardiac dose (0.04 mg epinephrine). [3, 9, 11, 30]

Question 322: A patient using a fentanyl transdermal patch for chronic pain presents for a routine cleaning. The dental hygienist should be most alert for which adverse effect?

Respiratory depression if additional opioids are given (Correct answer)
Xerostomia and caries risk only
Gingival hyperplasia
Tachycardia and hypertension

Correct answer: Respiratory depression if additional opioids are given

Opioid analgesics given on top of existing fentanyl therapy can cause additive respiratory depression, which is life-threatening.

Question 323: Which method is the GOLD STANDARD for assessing a patient's oral hygiene status at home?

X-ray interpretation
Disclosing agents with plaque index (Correct answer)
Patient self-report
Gingival inflammation scoring

Correct answer: Disclosing agents with plaque index

Disclosing agents stain plaque to make it visible, enabling accurate quantification using a plaque index during patient instruction.

Question 324: A nursing mother requires antibiotic therapy for a dental infection. Which drug is considered safest with minimal transfer to breast milk?

Metronidazole
Amoxicillin (Correct answer)
Tetracycline
Ciprofloxacin

Correct answer: Amoxicillin

Amoxicillin has low transfer to breast milk and is generally considered safe for nursing mothers, unlike tetracycline or fluoroquinolones which are contraindicated.

Question 325: Which immunoglobulin is the predominant antibody found in saliva and provides mucosal immunity?

IgA (Correct answer)
IgM
IgG
IgE

Correct answer: IgA

Secretory IgA is the dominant immunoglobulin in saliva and other mucous secretions, providing first-line mucosal defense.

Question 326: The CDC's recommended approach to managing dental unit waterlines (DUWLs) includes:

Installing UV filters as the single recommended intervention
A combination of flushing, antimicrobial treatment, and periodic water quality monitoring (Correct answer)
Using only sterile water in unit reservoirs and replacing weekly
Flushing waterlines for 2 minutes at the start of each day as the sole intervention

Correct answer: A combination of flushing, antimicrobial treatment, and periodic water quality monitoring

The CDC recommends a multifaceted approach to DUWL management combining waterline flushing, antimicrobial treatments, and periodic water quality monitoring.

Question 327: Which type of impression material is classified as an irreversible hydrocolloid?

Polyvinyl siloxane
Alginate (Correct answer)
Agar
Zinc oxide eugenol

Correct answer: Alginate

Alginate is an irreversible hydrocolloid because its gelation is a chemical reaction that cannot be reversed; it cannot be re-liquefied and reused.

Question 328: A patient asks how long they should brush their teeth. The evidence-based recommendation for toothbrushing time is:

2 minutes (Correct answer)
1 minute
5 minutes
30 seconds

Correct answer: 2 minutes

Two minutes is the evidence-based recommended brushing time endorsed by the American Dental Association. Studies show most people brush for less than one minute, which is insufficient for thorough plaque removal from all tooth surfaces.

Question 329: A torus palatinus is best defined as:

A malignant growth on the palate
An inflammatory cyst
A salivary gland tumor
A benign bony exostosis on the midline of the hard palate (Correct answer)

Correct answer: A benign bony exostosis on the midline of the hard palate

Torus palatinus is a benign bony exostosis located at the midline of the hard palate and is a common normal anatomic variant requiring no treatment unless it interferes with a prosthesis.

Question 330: Galvanic shock between two dissimilar metals in the mouth occurs due to which electrochemical process?

Corrosion of the nobler metal at the cathode
Oxidation of the nobler metal
Current flow from the less noble to the nobler metal through the electrolyte (Correct answer)
Reduction of the less noble metal

Correct answer: Current flow from the less noble to the nobler metal through the electrolyte

When two dissimilar metals contact in saliva (an electrolyte), current flows from the less noble (anode) to the nobler metal (cathode), causing the patient to feel a galvanic shock.

Question 331: A periapical radiograph shows a radiolucent lesion at the apex of a mandibular first molar with intact lamina dura. Vitality testing is positive. The most likely diagnosis is:

Incisive canal cyst
Normal anatomic variant such as the mental foramen (Correct answer)
Periapical cyst
Periapical granuloma

Correct answer: Normal anatomic variant such as the mental foramen

A radiolucency near the apex of a vital tooth with intact lamina dura most likely represents superimposition of the mental foramen, a normal anatomic structure.

Question 332: Fluoride works to prevent dental caries through which primary mechanism at the tooth surface?

Blocking plaque adhesion to enamel through surface coating
Directly killing all cariogenic bacteria in the oral cavity
Increasing salivary flow to dilute acids
Incorporation into hydroxyapatite to form fluorapatite, which is more acid-resistant, and promotion of remineralization during pH cycling (Correct answer)

Correct answer: Incorporation into hydroxyapatite to form fluorapatite, which is more acid-resistant, and promotion of remineralization during pH cycling

Fluoride's primary anticaries mechanism is ionic substitution in hydroxyapatite crystals to form fluorapatite (FAP), which has a higher critical pH, making enamel less susceptible to acid dissolution and facilitating remineralization.

Question 333: The 'red complex' periodontal pathogens identified by Socransky et al. include which three organisms?

Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola (Correct answer)
Campylobacter rectus, Eubacterium nodatum, and Peptostreptococcus micros
Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, and Prevotella intermedia
Streptococcus mutans, Actinomyces naeslundii, and Veillonella

Correct answer: Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola

The red complex (Socransky 1998) — P. gingivalis, T. forsythia (formerly B. forsythus), and T. denticola — shows the strongest association with clinical parameters of periodontitis severity and active disease.

Question 334: When applying fluoride varnish in a clinical setting, the clinician should instruct the patient to:

Avoid eating hard foods, hot beverages, and brushing for at least 4–6 hours after application (Correct answer)
Apply fluoride at home the same evening for enhanced effect
Rinse vigorously with water immediately after application
Refrain from all eating and drinking for 24 hours

Correct answer: Avoid eating hard foods, hot beverages, and brushing for at least 4–6 hours after application

After fluoride varnish application, patients should avoid hard/crunchy foods, hot drinks, and brushing for 4–6 hours to maximize fluoride uptake into enamel while the varnish remains on tooth surfaces.

Question 335: A patient is asked to protrude their mandible forward. Which muscle is the PRIMARY agonist for this action?

Temporalis muscle
Medial pterygoid muscle
Lateral pterygoid muscle (Correct answer)
Masseter muscle

Correct answer: Lateral pterygoid muscle

The lateral pterygoid muscle, particularly when both sides contract together, is the primary muscle responsible for protruding the mandible. The temporalis muscle primarily elevates and retracts the mandible, the masseter is a powerful elevator, and the medial pterygoid assists with elevation and side-to-side movements.

Question 336: A patient with xerostomia secondary to Sjögren's syndrome should receive which dental hygiene intervention to prevent root caries?

Increased sugar-free candy consumption to stimulate saliva
Regular fluoride rinsing with OTC fluoride only
Prescription-strength 1.1% sodium fluoride (5,000 ppm) toothpaste applied daily and fluoride varnish every 3 months (Correct answer)
Only nutritional counseling without topical fluoride

Correct answer: Prescription-strength 1.1% sodium fluoride (5,000 ppm) toothpaste applied daily and fluoride varnish every 3 months

Sjögren's syndrome causes severe xerostomia with dramatically elevated caries risk; prescription 5,000 ppm fluoride toothpaste (daily) combined with quarterly in-office fluoride varnish provides maximum caries protection.

Question 337: The dental hygiene plan for periodontal therapy's main goal is to:

Control dental caries
Reduce risk factors for periodontitis
Reduce bleeding on probing
Restore and maintain health of the periodontal tissues (Correct answer)

Correct answer: Restore and maintain health of the periodontal tissues

The primary goal of periodontal therapy is to restore and maintain the health of the periodontal tissues, which include the gums, alveolar bone, and periodontal ligaments. This involves eliminating inflammation, stopping disease progression, and promoting tissue regeneration to ensure the long-term stability and function of the teeth. Reducing bleeding, controlling caries, and reducing risk factors are all important steps that contribute to this overarching goal.

Question 338: Which component of the periodontal ligament (PDL) inserts into cementum on the tooth side and alveolar bone on the other?

Resting cells
Oxytalan fibers
Sharpey's fibers (Correct answer)
Intermediate plexus cells

Correct answer: Sharpey's fibers

Sharpey's fibers are the embedded portions of principal PDL fiber bundles that insert into both cementum and alveolar bone, anchoring the tooth in the socket.

Question 339: Informed consent in dental hygiene practice requires all of the following EXCEPT:

The patient must be guaranteed a specific treatment outcome (Correct answer)
Explanation of the proposed treatment and its purpose
Disclosure of reasonable alternatives
Discussion of potential risks and benefits

Correct answer: The patient must be guaranteed a specific treatment outcome

Informed consent requires disclosure of diagnosis, proposed treatment, risks/benefits, alternatives, and consequences of no treatment — but cannot guarantee specific outcomes, as individual variation exists.

Question 340: Which condition is characterized by a painful, recurrent ulceration on the oral mucosa with a yellow-gray pseudomembrane and an erythematous halo?

Traumatic ulcer
Aphthous ulcer (Correct answer)
Herpes labialis
Nicotinic stomatitis

Correct answer: Aphthous ulcer

Aphthous ulcers (canker sores) present as painful, recurrent mucosal ulcers surrounded by a red halo.

Question 341: The submandibular ganglion is associated with which cranial nerve for its preganglionic parasympathetic input?

CN VII via chorda tympani (Correct answer)
CN X
CN V3 directly
CN IX

Correct answer: CN VII via chorda tympani

Preganglionic parasympathetic fibers from the facial nerve (CN VII) travel via the chorda tympani to the lingual nerve, then synapse in the submandibular ganglion to supply the submandibular and sublingual glands.

Question 342: When applying fluoride varnish to an adult patient, what is the maximum recommended concentration of sodium fluoride?

2.26% (Correct answer)
5%
0.5%
1.1%

Correct answer: 2.26%

The standard professional fluoride varnish contains 5% NaF, which equals 2.26% fluoride ion by weight.

Question 343: Which composite resin curing shrinkage direction is most clinically significant when bonding to cavity walls?

Shrinkage away from the light source only
Shrinkage toward the bonded tooth structure, creating stress at the restoration interface (Correct answer)
Shrinkage toward the light source, pulling away from cavity walls
Uniform isotropic shrinkage with no preferred direction

Correct answer: Shrinkage toward the bonded tooth structure, creating stress at the restoration interface

Composite resins shrink toward bonded surfaces during polymerization. When the resin is bonded to cavity walls, the contraction stress pulls toward those walls, potentially breaking the adhesive bond or creating marginal gaps on unbonded surfaces — a phenomenon described by the C-factor (configuration factor).

Question 344: A dental hygienist who exceeds the scope of practice defined by their state's Dental Practice Act may face which of the following consequences?

Consequences borne solely by the supervising dentist, not the hygienist
Only a written warning for a first offense with no impact on licensure
A civil lawsuit only, because scope of practice violations are not criminal matters
License suspension or revocation, civil liability, and potentially criminal charges (Correct answer)

Correct answer: License suspension or revocation, civil liability, and potentially criminal charges

Practicing outside the legally defined scope of practice can result in disciplinary action by the state dental board (including license suspension or revocation), civil liability for patient harm, and in some cases criminal prosecution for unauthorized practice of dentistry.

Question 345: Oral candidiasis presenting as removable white plaques on an erythematous base is classified as which type?

Pseudomembranous candidiasis (Correct answer)
Hyperplastic candidiasis
Angular cheilitis
Erythematous candidiasis

Correct answer: Pseudomembranous candidiasis

Pseudomembranous candidiasis (thrush) presents as white, curd-like plaques that can be wiped away to reveal an erythematous base.

Question 346: During a periodontal chart, the dental hygienist records a probing depth of 4 mm at the midbuccal of tooth #19 with 2 mm of recession. The clinical attachment level (CAL) is:

8 mm
4 mm
2 mm
6 mm (Correct answer)

Correct answer: 6 mm

CAL = probing depth + recession (when the gingival margin is apical to the CEJ): 4 mm + 2 mm = 6 mm clinical attachment loss.

Question 347: A dental hygienist is performing coronal polishing on a patient with generalized enamel and a few composite restorations. To minimize abrasion and preserve the integrity of these surfaces, the polishing agent selected should have which characteristics?

A coarse grit and a dry application technique
Low hardness and small, round particle size (Correct answer)
Low speed of application and high pressure
High hardness and large, irregularly shaped particles

Correct answer: Low hardness and small, round particle size

The rate of abrasion is determined by the characteristics of the abrasive particles and the application technique. To be least abrasive, a polishing agent should have low hardness (softer than the surface being polished), small particle size, and regular, rounded particle shapes. This combination, applied with light pressure, will clean and polish with minimal removal of surface material.

Question 348: The Gram stain differentiates bacteria based on cell wall composition. Which characteristic is the basis of the Gram-positive reaction (purple/violet staining)?

Spore formation within the cell
A thick peptidoglycan cell wall that retains the crystal violet-iodine complex during decolorization (Correct answer)
Presence of an outer membrane lipopolysaccharide layer
High lipid content in the cell membrane

Correct answer: A thick peptidoglycan cell wall that retains the crystal violet-iodine complex during decolorization

Gram-positive bacteria have a thick, multilayered peptidoglycan cell wall that traps the crystal violet-iodine mordant complex during the alcohol decolorization step, resulting in a purple/violet color.

Question 349: A ghost image on a panoramic radiograph is characterized by:

Appearing on the opposite side of the object, higher and blurred (Correct answer)
Appearing below the object at the same horizontal level
Appearing on the same side as the object, higher and blurred
Appearing on the same side, sharper than the real image

Correct answer: Appearing on the opposite side of the object, higher and blurred

Ghost images on panoramic radiographs appear on the opposite side of the object, positioned higher and more blurred than the real image.

Question 350: Composite resin restorations undergo polymerization shrinkage. Which technique BEST reduces the clinical consequences of this shrinkage?

Incremental placement technique with each increment ≤2 mm (Correct answer)
Placing composite without bonding agent
Bulk placement in a single increment
Using a high-intensity curing light for the full bulk at once

Correct answer: Incremental placement technique with each increment ≤2 mm

Placing composite in increments of 2 mm or less and curing each layer independently reduces the volume contracting at any one time, minimizing stress at the tooth-restoration interface.

NBDHE Exam

The National Board Dental Hygiene Examination (NBDHE) assesses the ability of dental hygiene candidates to understand biomedical, dental, and dental hygiene sciences and to apply this knowledge in a problem-solving context.

350

Questions

540 min

Time Limit

75%

To Pass

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