ORE Part 1 Dental Exam — Questions and Answers

Question 1: What is 'Hutchinson's triad' and what condition does it indicate?

Signs of ectodermal dysplasia
Features of cretinism
Hutchinson's incisors (notched), interstitial keratitis, and nerve deafness — signs of congenital syphilis (Correct answer)
A triad of TMJ symptoms

Correct answer: Hutchinson's incisors (notched), interstitial keratitis, and nerve deafness — signs of congenital syphilis

Hutchinson's triad is pathognomonic of congenital syphilis: Hutchinson's incisors (barrel-shaped, notched), interstitial keratitis (corneal inflammation), and 8th nerve deafness (hearing loss).

Question 2: What is 'reactive oxygen species' involvement in periodontal disease?

Excessive ROS production by neutrophils during bacterial challenge damages host tissues (collagen, lipids, DNA), contributing to periodontal tissue destruction (Correct answer)
ROS are produced by periodontal bacteria to destroy host defences
ROS are beneficial antioxidants produced by the host
ROS only cause systemic disease, not periodontal destruction

Correct answer: Excessive ROS production by neutrophils during bacterial challenge damages host tissues (collagen, lipids, DNA), contributing to periodontal tissue destruction

In periodontal disease, sustained neutrophil activation produces excessive ROS beyond what is needed for bacterial killing. This oxidative stress damages host collagen, lipids, and DNA, contributing to bone and soft tissue destruction.

Question 3: What is the role of benzocaine topical anaesthetic in dental practice?

Used as a topical surface anaesthetic applied to mucosa before injection to reduce needle discomfort — works by superficial mucosal penetration only (Correct answer)
A type of vasoconstrictor added to LA cartridges
Used for systemic analgesia
Provides dental pulp anaesthesia without injection

Correct answer: Used as a topical surface anaesthetic applied to mucosa before injection to reduce needle discomfort — works by superficial mucosal penetration only

Benzocaine (and lidocaine) gels/sprays are applied topically to dry oral mucosa before injection to anaesthetise the superficial nerve endings, reducing the discomfort of needle insertion.

Question 4: What is the role of the silane coupling agent in composite resin?

Prevents discolouration of the restoration over time
Initiates the polymerisation reaction when light-activated
Reduces volumetric polymerisation shrinkage
Forms a chemical bond between the organic resin matrix and inorganic filler particles (Correct answer)

Correct answer: Forms a chemical bond between the organic resin matrix and inorganic filler particles

Silane coupling agents create a chemical (covalent) bond between the organic resin matrix and the inorganic filler particle surface, which is critical for load transfer and durability.

Question 5: What is a 'dentigerous cyst' and what does it arise from?

A cyst arising from the rest of Malassez
A developmental odontogenic cyst forming around the crown of an unerupted tooth by accumulation of fluid between the crown and the reduced enamel epithelium (Correct answer)
An inflammatory cyst at the apex of a non-vital tooth
A traumatic cyst with no epithelial lining

Correct answer: A developmental odontogenic cyst forming around the crown of an unerupted tooth by accumulation of fluid between the crown and the reduced enamel epithelium

The dentigerous cyst is the most common developmental odontogenic cyst. It develops from fluid accumulation between the crown and the reduced enamel epithelium of an unerupted (often impacted) tooth.

Question 6: Which drug is used as a reversal agent for benzodiazepine sedation in dentistry?

Atropine
Naloxone
Neostigmine
Flumazenil (Correct answer)

Correct answer: Flumazenil

Flumazenil is a competitive antagonist at the benzodiazepine binding site on the GABA-A receptor. It is used to reverse benzodiazepine sedation (midazolam) in emergency situations. However, its duration of action is shorter than midazolam, so re-sedation can occur and the patient must be monitored.

Question 7: Rectangular collimation of the X-ray beam reduces patient radiation dose by approximately what percentage compared to round collimation?

50–60% (Correct answer)
10–20%
80–90%
30–40%

Correct answer: 50–60%

Rectangular collimation reduces the irradiated tissue volume by approximately 50–60% compared to a standard round cone, significantly reducing patient dose. It restricts the beam to match the size of the receptor (film or sensor), eliminating unnecessary exposure of surrounding tissues.

Question 8: What is the evidence base for using low-level laser therapy (LLLT) in orofacial pain management?

Emerging evidence for benefit in TMD myofascial pain, oral mucositis, and dentine hypersensitivity — but evidence quality is currently insufficient to make strong recommendations in most guidelines (Correct answer)
LLLT is contraindicated in dental settings
LLLT is first-line for all orofacial pain per NICE
LLLT has no evidence base in dentistry

Correct answer: Emerging evidence for benefit in TMD myofascial pain, oral mucositis, and dentine hypersensitivity — but evidence quality is currently insufficient to make strong recommendations in most guidelines

LLLT uses low-power lasers to modulate tissue healing and pain. There is emerging evidence for benefit in TMD myofascial pain, post-irradiation mucositis, and dentine hypersensitivity, but the evidence base is still developing and guidelines do not yet recommend it as a mainstream standard of care.

Question 9: Which tooth is most commonly congenitally absent (excluding third molars)?

Lower central incisor
Upper lateral incisor
Lower second premolar (Correct answer)
Upper first premolar

Correct answer: Lower second premolar

The lower second premolar is the most commonly congenitally absent permanent tooth after the third molars. The upper lateral incisor is the second most commonly absent. Congenital absence (hypodontia) affects approximately 3–8% of the population for non-third-molar teeth.

Question 10: Which cranial nerve is responsible for the motor supply to the muscles of mastication?

Facial nerve (VII)
Trigeminal nerve (V) — mandibular division (Correct answer)
Glossopharyngeal nerve (IX)
Hypoglossal nerve (XII)

Correct answer: Trigeminal nerve (V) — mandibular division

The mandibular division (V3) of the trigeminal nerve provides motor innervation to the muscles of mastication (masseter, temporalis, medial and lateral pterygoids) as well as mylohyoid, anterior belly of digastric, tensor veli palatini, and tensor tympani.

Question 11: In the primary dentition, which tooth does NOT have a permanent successor?

Primary first molar
Primary second molar (replaced by a permanent premolar) (Correct answer)
Primary canine
All primary teeth have permanent successors

Correct answer: Primary second molar (replaced by a permanent premolar)

All primary teeth are replaced by permanent successors: primary incisors and canines by permanent incisors and canines; primary molars are replaced by premolars (not permanent molars).

Question 12: What is the management of an acute dentoalveolar abscess with facial swelling, raised temperature, and trismus?

Extraction only without drainage
Wait and see approach for 2 weeks
Urgent incision and drainage (I&D) of fluctuant swelling; extraction or pulp extirpation to remove source; antibiotics (amoxicillin) if systemic features; hospital referral if airway concern (Correct answer)
Antibiotics alone without drainage

Correct answer: Urgent incision and drainage (I&D) of fluctuant swelling; extraction or pulp extirpation to remove source; antibiotics (amoxicillin) if systemic features; hospital referral if airway concern

Acute abscess with systemic features requires surgical drainage (I&D if fluctuant swelling) as the primary treatment, removal of the source (extraction or RCT), and antibiotics for spreading infection with systemic features. Airway compromise (trismus, floor of mouth swelling) requires immediate hospital referral.

Question 13: What is 'mutually protected occlusion'?

An occlusion requiring no restorative intervention
An occlusion where all teeth share equal occlusal loading
An occlusal scheme where posterior teeth protect anterior teeth in maximum intercuspation, and anterior teeth protect posterior teeth during excursive movements (Correct answer)
An occlusal scheme used only for complete dentures

Correct answer: An occlusal scheme where posterior teeth protect anterior teeth in maximum intercuspation, and anterior teeth protect posterior teeth during excursive movements

In mutually protected (organically) occlusion: the posterior teeth protect anterior teeth from heavy vertical loading in MIP; the anterior teeth (canine guidance or group function) disocclude the posterior teeth during excursive movements.

Question 14: What is the recommended first-line analgesic regimen following dental extraction in an adult with no contraindications?

Diclofenac 50mg three times daily alone
Ibuprofen 400mg and paracetamol 1g taken together (Correct answer)
Codeine 60mg four times daily
Aspirin 600mg four times daily

Correct answer: Ibuprofen 400mg and paracetamol 1g taken together

The combination of ibuprofen 400mg and paracetamol 1g provides superior analgesia to either drug alone through synergistic action on different pain pathways. This combination is now recommended as first-line post-extraction analgesia in UK dental practice guidelines, avoiding the side effects of opioid-based alternatives.

Question 15: During surgical extraction of a lower third molar, the lingual nerve is most at risk at which anatomical location?

At the lingula of the mandible
At the mental foramen
At the level of the sigmoid notch
At the lingual plate of the third molar region, just below the alveolar crest (Correct answer)

Correct answer: At the lingual plate of the third molar region, just below the alveolar crest

The lingual nerve runs in close proximity to the lingual plate in the third molar region, often lying at or just below the level of the alveolar crest. Studies have shown it is directly on the bone surface in approximately 15% of cases, making it vulnerable during flap elevation and bone removal.

Question 16: A patient is taking a non-selective MAOI antidepressant. What dental anaesthetic concern arises?

Adrenaline should be used with extreme caution or avoided — MAOIs potentiate catecholamine effects, risking severe hypertension (Correct answer)
MAOIs increase the risk of LA allergy
MAOIs cause LA to be ineffective
No concern — MAOIs have no effect on dental anaesthetics

Correct answer: Adrenaline should be used with extreme caution or avoided — MAOIs potentiate catecholamine effects, risking severe hypertension

Non-selective MAOIs (e.g., phenelzine) prevent breakdown of catecholamines. Adding adrenaline may cause exaggerated and prolonged sympathomimetic effects including severe hypertensive crisis.

Question 17: What is the most common complication following extraction of maxillary molars?

Oroantral communication (Correct answer)
Mandibular fracture
Ludwig's angina
Inferior alveolar nerve damage

Correct answer: Oroantral communication

Oroantral communication (OAC) is the most common complication of upper molar extractions due to the close relationship between the molar roots and the maxillary sinus floor. If the OAC is less than 2mm, it may close spontaneously; larger communications require surgical closure with a buccal advancement flap.

Question 18: What is 'scalloped' basement membrane in the gingival epithelium?

The attachment of junctional epithelium to enamel
The undulating interface between the epithelium and underlying connective tissue, formed by rete ridges and connective tissue papillae (Correct answer)
The scalloped gingival margin shape
The CEJ morphology

Correct answer: The undulating interface between the epithelium and underlying connective tissue, formed by rete ridges and connective tissue papillae

The gingival epithelium has a scalloped (rete ridge) interface with the lamina propria. Rete ridges interdigitate with connective tissue papillae, increasing surface area and enhancing mechanical attachment.

Question 19: A patient with uncontrolled hyperthyroidism is at risk of which dental emergency?

Adrenal crisis
Hypoglycaemic episode
Myxoedema coma
Thyroid crisis (thyroid storm) (Correct answer)

Correct answer: Thyroid crisis (thyroid storm)

Thyroid crisis (thyroid storm) is a life-threatening exacerbation of hyperthyroidism that can be precipitated by stress, infection, or surgery. Signs include extreme tachycardia, hyperthermia, agitation, and cardiovascular collapse. Dental treatment should be deferred until the patient's thyroid function is controlled.

Question 20: What is 'peripheral sensitisation' in dental pulp pain?

Central sensitisation in the trigeminal nucleus
Sensitisation caused by local anaesthetic failure
Increased excitability of peripheral nociceptors due to inflammatory mediators (bradykinin, prostaglandins, substance P), lowering their activation threshold and producing pain hypersensitivity at the site of inflammation (Correct answer)
A process occurring only in neuropathic pain

Correct answer: Increased excitability of peripheral nociceptors due to inflammatory mediators (bradykinin, prostaglandins, substance P), lowering their activation threshold and producing pain hypersensitivity at the site of inflammation

Peripheral sensitisation occurs when inflammatory mediators released during pulpitis activate and sensitise nociceptors in the pulp. Lowered thresholds explain the disproportionate pain responses (hyperalgesia, allodynia) seen in irreversible pulpitis.

Question 21: Which type of composite resin contains the smallest filler particle size?

Macrofilled composite (10–50 μm)
Microfilled composite (0.04–0.4 μm) (Correct answer)
Hybrid composite (0.4–5 μm)
Packable composite (0.7–3.5 μm)

Correct answer: Microfilled composite (0.04–0.4 μm)

Microfilled composites contain colloidal silica particles of 0.04–0.4 μm, giving them outstanding polish retention and smooth surface finish, though at the cost of lower mechanical strength.

Question 22: What is the 'Angle Class I molar relationship'?

No specific cusp relationship — based on incisor position only
Mesiobuccal cusp of upper molar occludes distal to the lower molar buccal groove
Lower first molar is positioned mesial to upper first molar
Mesiobuccal cusp of upper first molar occludes in the buccal groove of the lower first molar (Correct answer)

Correct answer: Mesiobuccal cusp of upper first molar occludes in the buccal groove of the lower first molar

Angle Class I: the mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar. This is considered the ideal molar relationship.

Question 23: A 12-year-old child falls and avulses a permanent upper central incisor. The tooth has been dry for 45 minutes. What is the recommended reimplantation protocol?

Do not reimplant as the prognosis is poor
Reimplant immediately without any preparation
Soak in Hank's balanced salt solution for 30 minutes then reimplant
Soak in sodium fluoride solution, remove necrotic PDL, then reimplant and accept need for later root canal treatment (Correct answer)

Correct answer: Soak in sodium fluoride solution, remove necrotic PDL, then reimplant and accept need for later root canal treatment

When extra-alveolar dry time exceeds 60 minutes (or the PDL is clearly non-viable), the International Association of Dental Traumatology guidelines recommend removing the necrotic PDL, treating the root surface with fluoride, and reimplanting. Root canal treatment will be needed as revascularisation will not occur, but reimplantation preserves alveolar bone for later definitive treatment.

Question 24: A patient presents with multiple oral ulcers, genital ulcers and ocular inflammation. Which condition should be suspected?

Systemic lupus erythematosus
Pemphigus vulgaris
Behçet's disease (Correct answer)
Crohn's disease

Correct answer: Behçet's disease

The triad of recurrent oral ulcers, genital ulcers and uveitis (ocular inflammation) is the classic presentation of Behçet's disease. It is a systemic vasculitis more common in populations along the ancient Silk Road and requires multidisciplinary management.

Question 25: Which coagulation pathway is assessed by the prothrombin time (PT) and INR?

Intrinsic pathway
Common pathway only
Fibrinolytic pathway
Extrinsic pathway (Correct answer)

Correct answer: Extrinsic pathway

The PT/INR assesses the extrinsic and common coagulation pathways (factors VII, X, V, II, and fibrinogen). It is the standard monitoring test for warfarin therapy. The APTT, by contrast, assesses the intrinsic pathway and is used to monitor heparin therapy.

Question 26: What is the histological difference between an epithelial lined and non-epithelial-lined jaw cyst?

Odontogenic cysts (e.g., radicular, dentigerous) are lined by epithelium derived from tooth-forming tissues; traumatic (simple bone) cysts have no epithelial lining (Correct answer)
The difference is only relevant for malignant transformation risk
All jaw cysts are epithelial-lined by definition
Non-epithelial cysts cannot occur in the jaws

Correct answer: Odontogenic cysts (e.g., radicular, dentigerous) are lined by epithelium derived from tooth-forming tissues; traumatic (simple bone) cysts have no epithelial lining

True jaw cysts (radicular, dentigerous, OKC) are lined by epithelium. The simple (traumatic) bone cyst is a pseudocyst — an empty cavity within bone with no epithelial lining, probably representing an intraosseous haematoma.

Question 27: What is the role of tricyclic antidepressants (TCAs) in managing neuropathic orofacial pain?

TCAs are contraindicated in all orofacial pain management
TCAs (e.g., amitriptyline, nortriptyline) reduce central sensitisation and modulate descending pain inhibition — effective in low doses (10–75 mg) for neuropathic pain independently of antidepressant effect (Correct answer)
TCAs only work for pain in depressed patients
TCAs act by stimulating endogenous opioids only

Correct answer: TCAs (e.g., amitriptyline, nortriptyline) reduce central sensitisation and modulate descending pain inhibition — effective in low doses (10–75 mg) for neuropathic pain independently of antidepressant effect

Low-dose TCAs (amitriptyline 10–25 mg nightly) are first or second-line for neuropathic pain (PDAP, burning mouth, post-herpetic neuralgia). They modulate descending pain inhibitory pathways and reduce central sensitisation.

Question 28: What is 'pericoronitis' and which tooth is most commonly affected?

An abscess within the dental pulp
Inflammation of the soft tissue operculum overlying an incompletely erupted tooth — most commonly the mandibular third molar (wisdom tooth) (Correct answer)
Inflammation around the apex of any tooth
Gingival inflammation around all erupting teeth

Correct answer: Inflammation of the soft tissue operculum overlying an incompletely erupted tooth — most commonly the mandibular third molar (wisdom tooth)

Pericoronitis is acute or chronic inflammation of the pericoronal flap (operculum) covering an incompletely erupted tooth. It is most commonly associated with the lower third molar, often complicated by bacterial colonisation under the flap.

Question 29: What are A-delta and C fibres in the context of dental pain?

C fibres only carry proprioception from the PDL
A-delta fibres carry light touch only
A-delta and C are both types of motor nerve fibres
A-delta fibres: myelinated, fast-conducting (sharp, well-localised pain); C fibres: unmyelinated, slow-conducting (dull, burning, poorly localised, thermal pain) — both transmit nociceptive signals in dental pulp (Correct answer)

Correct answer: A-delta fibres: myelinated, fast-conducting (sharp, well-localised pain); C fibres: unmyelinated, slow-conducting (dull, burning, poorly localised, thermal pain) — both transmit nociceptive signals in dental pulp

Both nerve types carry nociceptive signals from dental pulp and periodontium. A-delta fibres produce the sharp, well-localised 'first pain' response. C fibres produce the dull, burning, poorly localised 'second pain' response.

Question 30: Which type of dentine is formed as a physiological response throughout life?

Tertiary (reparative) dentine
Secondary dentine (Correct answer)
Mantle dentine
Primary dentine

Correct answer: Secondary dentine

Secondary dentine is deposited slowly and continuously by odontoblasts throughout the life of a vital tooth, after root formation is complete. This gradually reduces the size of the pulp chamber. Tertiary dentine, by contrast, is formed as a pathological response to stimuli such as caries or attrition.

Question 31: Which movement of the TMJ is described as the 'hinge movement'?

Translation of the condyle down the articular eminence
Pure rotation of the condyle around a transverse axis in the lower joint compartment (inferior joint space) (Correct answer)
Lateral pterygoid protrusion
Combined Bennett and rotation movement

Correct answer: Pure rotation of the condyle around a transverse axis in the lower joint compartment (inferior joint space)

The hinge (rotational) movement of the mandible occurs in the inferior compartment of the TMJ, with the condyle rotating around a transverse axis. Pure rotation allows approximately 20–25 mm of mouth opening.

Question 32: What is a 'periapical index' (PAI) and how is it used?

A scoring system for caries severity on radiographs
A measurement of root length on radiographs
A standardised radiographic scoring system (1–5) for assessing periapical pathology severity on radiographs — used in research and clinical outcome assessment of endodontic treatment (Correct answer)
A clinical index for assessing gingival inflammation

Correct answer: A standardised radiographic scoring system (1–5) for assessing periapical pathology severity on radiographs — used in research and clinical outcome assessment of endodontic treatment

The Periapical Index (Ørstavik 1986) scores the periapical appearance on a 1–5 scale: 1 = normal bone structure; 5 = severe periodontitis with features of systemic spread. Used to assess endodontic treatment success.

Question 33: A patient with a known cardiac murmur is scheduled for dental extraction. According to current NICE guidelines, what is the recommended antibiotic prophylaxis regimen?

Amoxicillin 3g orally one hour before
Azithromycin 500mg orally one hour before
No routine antibiotic prophylaxis is recommended (Correct answer)
Clindamycin 600mg orally one hour before

Correct answer: No routine antibiotic prophylaxis is recommended

NICE Clinical Guideline CG64 (updated) states that antibiotic prophylaxis against infective endocarditis is NOT routinely recommended for dental procedures in the UK, regardless of the cardiac condition. This differs from American Heart Association guidelines and is a key point for the ORE examination.

Question 34: What is the pathogenesis of periapical abscess formation?

Bacterial products from pulp necrosis spread beyond the apex, triggering acute inflammation with neutrophil accumulation and pus formation in the periapical tissues (Correct answer)
An allergic reaction to pulp bacteria
Viral infection of the periapical tissues
Direct bacterial spread from the gingival pocket

Correct answer: Bacterial products from pulp necrosis spread beyond the apex, triggering acute inflammation with neutrophil accumulation and pus formation in the periapical tissues

Pulp necrosis from caries/trauma allows bacteria to colonise the root canal. Bacteria and their products exit the apex, stimulating acute inflammatory infiltrate (mainly neutrophils), resulting in pus accumulation (abscess) in periapical bone or soft tissue.

Question 35: What radiation detector is worn by dental radiographers for personal dose monitoring?

Thermoluminescent dosimeter (TLD) badge or electronic personal dosimeter (EPD) (Correct answer)
Photographic film in a lead apron pocket
A Geiger counter
No monitoring device is required for dental staff

Correct answer: Thermoluminescent dosimeter (TLD) badge or electronic personal dosimeter (EPD)

Classified workers (those whose annual dose may exceed 3/10 of dose limits) wear TLD badges or EPDs for personal dose monitoring. These track cumulative exposure and must be reviewed regularly.

Question 36: What is the significance of 'lamina dura' in periapical radiographs?

A normal finding only in children
A calcified ligament visible only on bitewing radiographs
The border of a cystic lesion
A white line on the radiograph representing the dense cortical bone lining the tooth socket — loss of lamina dura indicates periapical pathology or periodontitis (Correct answer)

Correct answer: A white line on the radiograph representing the dense cortical bone lining the tooth socket — loss of lamina dura indicates periapical pathology or periodontitis

The lamina dura (radiographic white line) represents the dense cortical bone (alveolar bone proper) lining the tooth socket. Its loss in the periapical region indicates periapical pathology; loss in the crestal region suggests periodontitis.

Question 37: What is the angle formed between the occlusal plane and the condylar guidance path called?

The Frankfort angle
The Fischer angle (or Bennett angle — actually these differ; the angle between condylar path and occlusal plane is the Balkwill angle) (Correct answer)
The Monson angle
The Bennett angle

Correct answer: The Fischer angle (or Bennett angle — actually these differ; the angle between condylar path and occlusal plane is the Balkwill angle)

The Balkwill angle (approximately 26°) is formed between the occlusal plane and the path of the condyle. The Bennett angle is the angle formed by the working side condyle moving laterally.

Question 38: What is the relationship between Streptococcus mutans and dental caries initiation?

S. mutans causes periodontal disease
S. mutans is a harmless commensal in the oral cavity
S. mutans produces lactic acid from fermentable sugars, acid-tolerant, produces glucan biofilm matrix, and initiates enamel demineralisation — it is the primary initiator of coronal caries (Correct answer)
S. mutans is only involved in root caries

Correct answer: S. mutans produces lactic acid from fermentable sugars, acid-tolerant, produces glucan biofilm matrix, and initiates enamel demineralisation — it is the primary initiator of coronal caries

S. mutans is the primary pathogen in the initiation of coronal dental caries. It metabolises sucrose to lactic acid, produces extracellular glucans enabling biofilm adherence, and is highly aciduric and acidogenic.

Question 39: Which permanent tooth has the longest root?

Maxillary canine (Correct answer)
Maxillary central incisor
Mandibular central incisor
Mandibular first molar

Correct answer: Maxillary canine

The maxillary canine has the longest root of all permanent teeth, making it very stable in the arch and explaining why it is typically the last anterior tooth extracted when arch preservation is needed.

Question 40: Why is adrenaline (epinephrine) added to dental local anaesthetic cartridges?

To reduce the pH of the solution
To increase the speed of anaesthetic onset
To cause vasoconstriction, reducing systemic absorption, prolonging duration of anaesthesia, and providing a bloodless operative field (Correct answer)
To reduce the risk of allergic reaction

Correct answer: To cause vasoconstriction, reducing systemic absorption, prolonging duration of anaesthesia, and providing a bloodless operative field

Adrenaline (1:80,000 or 1:100,000) causes local vasoconstriction, reducing blood flow at the injection site. This slows systemic absorption, prolongs anaesthetic effect, and reduces bleeding in the surgical field.

Question 41: Addison's disease is characterised by insufficiency of which endocrine gland?

Thyroid gland
Pituitary gland
Parathyroid gland
Adrenal cortex (Correct answer)

Correct answer: Adrenal cortex

Addison's disease (primary adrenal insufficiency) results from destruction of the adrenal cortex, leading to deficiency of cortisol and aldosterone. Dental relevance includes risk of adrenal crisis during stress and characteristic oral hyperpigmentation. Steroid supplementation may be needed before invasive dental procedures.

Question 42: A patient on warfarin with an INR of 3.2 presents for extraction of a single-rooted tooth. According to SDCEP guidance, what is the recommended approach?

Convert to heparin bridging therapy
Proceed with extraction using local haemostatic measures (Correct answer)
Postpone until INR is below 2.0
Stop warfarin 3 days before extraction

Correct answer: Proceed with extraction using local haemostatic measures

SDCEP guidance recommends that patients with a stable INR of 4.0 or below can have up to 3 simple extractions in general practice with local haemostatic measures (oxidised cellulose, sutures, tranexamic acid mouthwash). Warfarin should NOT be stopped as the thromboembolic risk outweighs the bleeding risk.

Question 43: Which suture material is most commonly used for intraoral wound closure following surgical extraction?

Nylon (non-resorbable)
Polyglycolic acid (resorbable) (Correct answer)
Silk (non-resorbable)
Stainless steel wire

Correct answer: Polyglycolic acid (resorbable)

Resorbable sutures such as polyglycolic acid (Vicryl) are most commonly used for intraoral closure as they do not require a separate removal appointment and are broken down by hydrolysis. Silk, while still used, harbours bacteria and is non-resorbable, requiring removal at review.

Question 44: Which nerve provides sensory innervation to the buccal gingivae of the mandibular molars?

Mylohyoid nerve
Long buccal nerve (Correct answer)
Inferior alveolar nerve
Mental nerve

Correct answer: Long buccal nerve

The long buccal nerve (buccal branch of the mandibular division of the trigeminal nerve) provides sensory innervation to the buccal gingivae of the mandibular molars. This is why a separate long buccal nerve block is required in addition to an inferior alveolar nerve block when extracting lower molars.

Question 45: What is 'amelogenesis imperfecta'?

Enamel dissolution caused by acid erosion
A hereditary condition affecting enamel formation causing hypoplasia, hypomineralisation, or hypomaturation — teeth affected throughout the dentition in both dentitions (Correct answer)
A form of dentine dysplasia
A condition caused by fluoride excess only

Correct answer: A hereditary condition affecting enamel formation causing hypoplasia, hypomineralisation, or hypomaturation — teeth affected throughout the dentition in both dentitions

Amelogenesis imperfecta (AI) is a group of hereditary conditions affecting enamel formation genes (AMELX, ENAM, MMP20 etc.). It causes enamel defects ranging from hypoplasia (thin) to hypomineralisation (soft/discoloured) affecting all teeth.

Question 46: What is the specific indication for using IV paracetamol (Perfalgan) in dental/oral surgical settings?

When oral route is unavailable or rapid onset analgesia is needed peri- or post-operatively under general anaesthesia — achieves therapeutic levels in 15 minutes (Correct answer)
For routine dental procedures in conscious patients
As a loading dose before oral paracetamol is started at home
Only for patients allergic to ibuprofen

Correct answer: When oral route is unavailable or rapid onset analgesia is needed peri- or post-operatively under general anaesthesia — achieves therapeutic levels in 15 minutes

IV paracetamol (Perfalgan) is used in hospital oral surgical settings when patients cannot take oral medication (post-GA) or rapid onset is needed. IV route achieves peak concentrations faster than oral, providing prompt perioperative analgesia.

Question 47: During elevation of a lower third molar root, the root tip is displaced lingually. What is the immediate best course of action?

Take a radiograph, note the location, and refer to a specialist oral surgeon (Correct answer)
Leave it and inform the patient
Raise a lingual flap and retrieve under direct vision
Attempt retrieval with a Mitchell's trimmer through the socket

Correct answer: Take a radiograph, note the location, and refer to a specialist oral surgeon

A displaced root fragment in the lingual tissues should not be pursued through the socket or by raising a lingual flap in a general practice setting, as this risks lingual nerve damage and displacement into deeper tissue spaces. The correct approach is to document the event radiographically and refer to a specialist.

Question 48: What role do endorphins and endogenous opioids play in dental pain?

Endorphins increase pain sensitivity
Endorphins only affect emotional responses to pain
Endorphins have no role in dental pain
Endorphins (beta-endorphin) and enkephalins bind to opioid receptors in the brain and spinal cord, activating descending inhibitory pathways that reduce nociceptive transmission — the basis of placebo analgesia and acupuncture effects (Correct answer)

Correct answer: Endorphins (beta-endorphin) and enkephalins bind to opioid receptors in the brain and spinal cord, activating descending inhibitory pathways that reduce nociceptive transmission — the basis of placebo analgesia and acupuncture effects

The endogenous opioid system (beta-endorphins, enkephalins, dynorphins) activates mu, delta, and kappa receptors, inhibiting pain transmission in the dorsal horn and activating descending pain inhibitory pathways. This system underpins placebo analgesia and contributes to anxiety-pain links.

Question 49: How should a pregnant dental worker's radiation exposure be managed?

Once pregnancy is declared, dose to the abdomen/foetus must not exceed 1 mSv for the remainder of pregnancy; reassign to limit exposure if workplace assessment indicates significant risk (Correct answer)
No special precautions are needed during pregnancy for dental radiography
Pregnant workers must wear double lead aprons
Pregnant workers must stop all radiography work immediately

Correct answer: Once pregnancy is declared, dose to the abdomen/foetus must not exceed 1 mSv for the remainder of pregnancy; reassign to limit exposure if workplace assessment indicates significant risk

IRR17 requires that once pregnancy is declared, the employer must ensure the dose to the foetus does not exceed 1 mSv for the remainder of pregnancy. Given typical dental X-ray scatter levels, this is rarely an issue, but a risk assessment must be carried out.

Question 50: What is the 'Frankfort plane' and what is it used for in orthodontic assessment?

The mandibular plane
A horizontal reference plane from the inferior margin of the orbit (orbitale) to the tragus/superior margin of the external auditory meatus — used as a standard reference in cephalometric analysis (Correct answer)
The occlusal plane
The palatal plane

Correct answer: A horizontal reference plane from the inferior margin of the orbit (orbitale) to the tragus/superior margin of the external auditory meatus — used as a standard reference in cephalometric analysis

The Frankfort Horizontal plane is defined by the infraorbital rim and porion (external auditory meatus). It represents the natural head position and is a key reference plane in lateral cephalometric radiograph analysis.

Question 51: What is the oral surgical management of trigeminal neuralgia when pharmacological treatment fails?

Microvascular decompression (MVD), Gamma Knife radiosurgery, percutaneous rhizotomy (glycerol/balloon/radiofrequency) — specialist neurosurgical referral required (Correct answer)
Dental splint therapy
Coronectomy of lower third molars
Tooth extraction of all teeth in the affected distribution

Correct answer: Microvascular decompression (MVD), Gamma Knife radiosurgery, percutaneous rhizotomy (glycerol/balloon/radiofrequency) — specialist neurosurgical referral required

When carbamazepine/pharmacotherapy fails, surgical options for TN include: MVD (decompresses the trigeminal root from a vascular loop — most durable), Gamma Knife stereotactic radiosurgery (non-invasive), and percutaneous rhizotomy procedures. All require specialist neurosurgical referral.

Question 52: What is the normal resting blood pressure range for a healthy adult according to NICE hypertension guidelines?

Below 140/90 mmHg (Correct answer)
Below 130/85 mmHg
Below 150/90 mmHg
Below 120/80 mmHg

Correct answer: Below 140/90 mmHg

NICE guidelines define hypertension as a clinic blood pressure persistently at or above 140/90 mmHg (with ambulatory or home monitoring confirmation at 135/85 mmHg). Below 140/90 is considered the normal range in clinical practice, though lower targets may apply for certain patient groups.

Question 53: What is the most common benign salivary gland tumour?

Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Warthin's tumour
Pleomorphic adenoma (Correct answer)

Correct answer: Pleomorphic adenoma

Pleomorphic adenoma accounts for approximately 60–70% of all salivary gland tumours and is the most common benign tumour. It most frequently occurs in the parotid gland and presents as a slow-growing, painless, firm swelling. Treatment is surgical excision with adequate margin.

Question 54: Which fascial space infection carries the highest risk of airway compromise?

Canine space
Infraorbital space
Buccal space
Ludwig's angina (bilateral submandibular space) (Correct answer)

Correct answer: Ludwig's angina (bilateral submandibular space)

Ludwig's angina involves bilateral infection of the submandibular, sublingual, and submental spaces, causing rapid swelling of the floor of the mouth and tongue elevation. This can lead to fatal airway obstruction and is a surgical emergency requiring immediate hospital admission, IV antibiotics, and potentially surgical decompression or tracheostomy.

Question 55: What is the mechanism of action of articaine, the most widely used local anaesthetic in UK dental practice?

Blocks calcium channels to reduce neurotransmitter release
Stimulates GABA receptors to inhibit pain transmission
Blocks voltage-gated sodium channels in the neuronal membrane, preventing action potential propagation and nerve conduction (Correct answer)
Acts centrally on the thalamus to reduce pain perception

Correct answer: Blocks voltage-gated sodium channels in the neuronal membrane, preventing action potential propagation and nerve conduction

Articaine (like all local anaesthetics) blocks voltage-gated Na+ channels in the axon membrane, preventing depolarisation and action potential propagation, achieving reversible nerve conduction blockade.

Question 56: What is the typical eruption sequence of the mandibular permanent teeth?

Central incisor, lateral incisor, first molar, canine, first premolar, second premolar, second molar
First molar, canine, incisors, premolars, second molar
First molar, central incisor, lateral incisor, canine, first premolar, second premolar, second molar, third molar (Correct answer)
Incisors first in mandible, molars first in maxilla

Correct answer: First molar, central incisor, lateral incisor, canine, first premolar, second premolar, second molar, third molar

The mandibular permanent eruption sequence is typically: 1st molar (6yrs), central incisor (6–7), lateral incisor (7–8), canine (9–10), 1st premolar (10–11), 2nd premolar (11–12), 2nd molar (11–13), 3rd molar (17–21).

Question 57: According to UK IRMER regulations, which professional is responsible for justifying a dental radiograph?

The radiographer
The dental nurse
The referrer or practitioner (usually the dentist) (Correct answer)
The patient

Correct answer: The referrer or practitioner (usually the dentist)

Under the Ionising Radiation (Medical Exposure) Regulations 2017 (IR(ME)R), the practitioner is responsible for justifying each radiographic exposure. In dentistry, this is typically the dentist who must ensure that each radiograph provides a net benefit to the patient and cannot be replaced by a non-ionising alternative.

Question 58: What is the effective dose from a full mouth periapical series of radiographs (approximately)?

Equal to 1 chest X-ray (0.1 mSv)
Less than 1 µSv total
Equivalent to a CT head scan
Approximately 30–100 µSv (microsieverts) depending on technique and equipment (Correct answer)

Correct answer: Approximately 30–100 µSv (microsieverts) depending on technique and equipment

A full periapical series delivers approximately 30–100 µSv effective dose, roughly equivalent to a few days of natural background radiation. Individual periapicals are approximately 1–8 µSv each.

Question 59: What is the maximum recommended dose of lidocaine with 1:80,000 adrenaline for a 70kg adult?

4.4mg/kg (308mg) (Correct answer)
2.0mg/kg (140mg)
3.0mg/kg (210mg)
7.0mg/kg (490mg)

Correct answer: 4.4mg/kg (308mg)

The maximum recommended dose of lidocaine with adrenaline (epinephrine) is 4.4mg/kg (or 7.0mg/kg in some older references, though 4.4mg/kg is the widely accepted GDC standard), up to an absolute maximum of 500mg. Each 2.2ml cartridge of 2% lidocaine contains 44mg, so a 70kg adult can receive approximately 7 cartridges.

Question 60: A diabetic patient becomes sweaty, confused, and tremulous during a dental appointment. What is the most appropriate immediate management?

Place patient supine and wait
Administer sublingual GTN
Give oral glucose gel or a sugary drink if conscious (Correct answer)
Administer intramuscular adrenaline

Correct answer: Give oral glucose gel or a sugary drink if conscious

These are signs of hypoglycaemia. If the patient is conscious and can swallow, the immediate treatment is oral glucose (glucose gel, tablets, or a sugary drink such as orange juice). If unconscious, intramuscular glucagon 1mg should be administered. This is a core medical emergency scenario for the GDC.

Question 61: A patient is prescribed metronidazole 400 mg TDS for a periodontal condition. What is the recommended duration?

Until symptoms resolve without a defined end date
14 days for all dental infections
28 days
7 days (or up to 7 days maximum for acute infections) (Correct answer)

Correct answer: 7 days (or up to 7 days maximum for acute infections)

Metronidazole for acute dental/periodontal infections is prescribed for 7 days (400 mg TDS in adults). Shorter courses (3–5 days) may be used for specific indications. Prolonged courses are not recommended due to resistance risk.

Question 62: What is the primary setting reaction of addition silicone (PVS) impression material?

Platinum-catalysed hydrosilylation of Si-H groups across vinyl groups (Correct answer)
Acid-base neutralisation between base and catalyst pastes
Radical chain-growth polymerisation initiated by benzoyl peroxide
Polycondensation releasing ethanol as a volatile by-product

Correct answer: Platinum-catalysed hydrosilylation of Si-H groups across vinyl groups

Addition silicones set via a platinum-catalysed hydrosilylation reaction in which Si-H groups add across vinyl (Si-CH=CH2) groups with no by-product released, giving excellent accuracy and dimensional stability.

Question 63: What is the radiographic appearance of a radicular (periapical) cyst?

Well-defined radiolucency at the root apex with a corticated (white) margin, continuous with the lamina dura, associated with a non-vital tooth (Correct answer)
Diffuse ill-defined radiolucency at the tooth apex
A multilocular radiolucency above an erupted tooth
A radiopaque lesion at the apex

Correct answer: Well-defined radiolucency at the root apex with a corticated (white) margin, continuous with the lamina dura, associated with a non-vital tooth

The periapical (radicular) cyst typically appears as a well-defined, round/oval radiolucency at the root apex with a corticated border (continuous with the lamina dura), associated with a non-vital tooth. It is indistinguishable radiographically from a periapical granuloma.

Question 64: A patient collapses in the dental chair and is unresponsive with no pulse. What is the correct compression-to-ventilation ratio for adult CPR?

30:1
15:1
15:2
30:2 (Correct answer)

Correct answer: 30:2

The Resuscitation Council (UK) guidelines recommend a compression-to-ventilation ratio of 30:2 for adult basic life support. Compressions should be performed at a rate of 100–120 per minute, at a depth of 5–6 cm, with minimal interruptions. An AED should be applied as soon as available.

Question 65: Which cells are responsible for forming cementum?

Ameloblasts
Fibroblasts
Cementoblasts (Correct answer)
Osteoblasts

Correct answer: Cementoblasts

Cementoblasts are the specialised cells responsible for forming cementum. They originate from the dental follicle (ectomesenchyme) and deposit cementum matrix on the root surface. Some cementoblasts become entrapped within the cementum they produce, becoming cementocytes.

Question 66: What is the dental significance of long-term steroid therapy?

Steroids only affect healing, not emergency risk
Adrenal suppression may cause an 'adrenal crisis' under surgical stress — doubling of steroid dose ('steroid cover') or consultation with medical team required before invasive procedures (Correct answer)
Only relevant if steroids are given intravenously
No dental significance

Correct answer: Adrenal suppression may cause an 'adrenal crisis' under surgical stress — doubling of steroid dose ('steroid cover') or consultation with medical team required before invasive procedures

Long-term systemic steroids suppress the HPA axis (adrenal suppression). Surgical stress cannot trigger the normal cortisol surge, risking Addisonian crisis (hypotension, collapse). Historically, 'steroid cover' was applied; current guidance is more nuanced and patient-specific.

Question 67: What does the ALARP principle stand for in dental radiography?

As Long As Reasonably Practicable
As Low As Reasonably Practicable (Correct answer)
Assessed Levels Are Routinely Plotted
Always Limit All Radiation Procedures

Correct answer: As Low As Reasonably Practicable

ALARP stands for As Low As Reasonably Practicable. It is the UK regulatory principle requiring that radiation doses be kept as low as is reasonably practicable while still obtaining diagnostically adequate images. This includes using rectangular collimation, correct exposure settings, and digital sensors where possible.

Question 68: Which phase in conventional dental amalgam is most susceptible to corrosion?

Gamma phase (Ag3Sn)
Beta phase (Ag2Hg)
Gamma-2 phase (Sn8Hg) (Correct answer)
Gamma-1 phase (Ag2Hg3)

Correct answer: Gamma-2 phase (Sn8Hg)

The gamma-2 phase (Sn8Hg) is the weakest and most corrosion-susceptible phase in conventional amalgam, which is why high-copper amalgams were developed to eliminate it.

Question 69: What oral manifestation is characteristic of Addison's disease?

Painful ulcers on the lip
Diffuse melanotic (brown) pigmentation of the oral mucosa, particularly the buccal mucosa (Correct answer)
White patches on the tongue
Petechiae on the palate

Correct answer: Diffuse melanotic (brown) pigmentation of the oral mucosa, particularly the buccal mucosa

Addison's disease (primary adrenal insufficiency) causes excess ACTH secretion which stimulates melanocytes, producing diffuse mucosal hyperpigmentation, characteristically on the buccal mucosa, gingivae, and lips.

Question 70: Which hepatitis virus is most commonly transmitted through needlestick injuries in the dental setting?

Hepatitis B (Correct answer)
Hepatitis A
Hepatitis D
Hepatitis C

Correct answer: Hepatitis B

Hepatitis B has the highest transmission rate via needlestick injury (approximately 30% from an infected source), compared to hepatitis C (approximately 3%) and HIV (approximately 0.3%). This is why hepatitis B vaccination is mandatory for all dental healthcare workers in the UK.

Question 71: What is the dental formula for the permanent human dentition?

I 1/1, C 1/1, P 2/2, M 3/3 = 30 teeth
I 2/2, C 1/1, P 2/2, M 3/3 = 32 teeth total (Correct answer)
I 2/2, C 2/2, P 2/2, M 3/3 = 36 teeth
I 2/2, C 1/1, P 2/2, M 2/2 = 28 teeth

Correct answer: I 2/2, C 1/1, P 2/2, M 3/3 = 32 teeth total

The permanent human dental formula is: 2 incisors, 1 canine, 2 premolars, 3 molars per quadrant, totalling 32 teeth (including third molars/wisdom teeth).

Question 72: What is the primary clinical advantage of resin-modified glass ionomer cement (RMGIC) over conventional GIC?

Greater compressive strength
Reduced sensitivity to moisture during initial setting (Correct answer)
Better translucency and aesthetics
Significantly higher fluoride release

Correct answer: Reduced sensitivity to moisture during initial setting

RMGIC incorporates a resin component that provides an immediate light-cure set, greatly reducing the moisture sensitivity that is the chief clinical weakness of conventional GIC during early setting.

Question 73: What is the correct dose of intramuscular adrenaline for an adult experiencing anaphylaxis in a dental surgery?

0.5ml of 1:1000 (0.5mg) (Correct answer)
1ml of 1:1000 (1mg)
1ml of 1:10,000 (0.1mg)
0.1ml of 1:1000 (0.1mg)

Correct answer: 0.5ml of 1:1000 (0.5mg)

The Resuscitation Council (UK) guidelines recommend 0.5ml of 1:1000 adrenaline (500 micrograms) given intramuscularly into the anterolateral thigh for adult anaphylaxis. This can be repeated every 5 minutes if there is no improvement. Intravenous adrenaline should only be given by experienced specialists.

Question 74: What is centric relation (CR) in prosthodontic terms?

The rest position of the mandible
The position of maximum tooth contact
The maxillomandibular relationship when the condyles are in their most superior and anterior position in the glenoid fossae, regardless of tooth contact (Correct answer)
The relationship determined by muscle activity alone

Correct answer: The maxillomandibular relationship when the condyles are in their most superior and anterior position in the glenoid fossae, regardless of tooth contact

Centric relation (updated definition) is the position when the mandibular condyles are in their most superoanterior position against the posterior slope of the articular eminence, providing a reproducible reference for prosthodontic construction.

Question 75: How many root canals does a mandibular first molar typically have?

Four
Three (Correct answer)
Two
Five

Correct answer: Three

The mandibular first molar typically has two roots (mesial and distal) with three root canals — two in the mesial root (mesiobuccal and mesiolingual) and one in the distal root. However, a second distal canal is found in approximately 30% of cases, making four canals common.

Question 76: What is the typical overjet and overbite in an ideal Class I occlusion?

Overjet 4 mm; overbite 0 mm (edge-to-edge)
Overjet 0 mm; overbite 0 mm
Overjet 5–10 mm; overbite 6 mm
Overjet 2–4 mm; overbite 2–4 mm (covering approximately one-third of lower incisor) (Correct answer)

Correct answer: Overjet 2–4 mm; overbite 2–4 mm (covering approximately one-third of lower incisor)

In an ideal Class I occlusion, the overjet (horizontal overlap) is 2–4 mm and the overbite (vertical overlap) is 2–4 mm, covering approximately one-third of the lower incisor crown height.

Question 77: What is the mode of inheritance of dentinogenesis imperfecta?

Autosomal dominant — caused by mutations in DSPP (dentin sialophosphoprotein) gene (Correct answer)
X-linked recessive
Autosomal recessive
Multifactorial with no single gene

Correct answer: Autosomal dominant — caused by mutations in DSPP (dentin sialophosphoprotein) gene

Dentinogenesis imperfecta (DI types II and III) is inherited as autosomal dominant. It is caused by mutations in the DSPP gene. Affected teeth appear grey-blue/amber with bulbous crowns and obliterated pulp chambers.

Question 78: Which cells are responsible for dentine formation?

Ameloblasts
Osteoblasts
Odontoblasts (Correct answer)
Cementoblasts

Correct answer: Odontoblasts

Odontoblasts are the dentine-forming cells derived from neural crest cells. They line the pulp chamber and extend processes into dentinal tubules (Tomes' fibres), producing predentine which mineralises to become dentine.

Question 79: The cementoenamel junction (CEJ) shows three possible relationships. Which is the most common arrangement?

Enamel overlaps cementum
Cementum and enamel meet edge to edge
A gap exists between cementum and enamel exposing dentine
Cementum overlaps enamel (Correct answer)

Correct answer: Cementum overlaps enamel

In approximately 60% of teeth, cementum overlaps the enamel at the CEJ. In about 30%, they meet edge to edge, and in approximately 10%, there is a gap exposing the underlying dentine, which can contribute to cervical sensitivity.

Question 80: What is the mechanism of action of fluoride in preventing dental caries?

Fluoride kills all oral bacteria
Fluoride incorporates into hydroxyapatite to form fluorapatite (more acid-resistant); enhances remineralisation; inhibits bacterial enzymes (Correct answer)
Fluoride dissolves calculus deposits
Fluoride strengthens enamel by increasing its thickness

Correct answer: Fluoride incorporates into hydroxyapatite to form fluorapatite (more acid-resistant); enhances remineralisation; inhibits bacterial enzymes

Fluoride's anti-caries effect is multi-factorial: (1) substitution into hydroxyapatite forming fluorapatite (acid-resistant), (2) enhancing remineralisation post-acid attack, and (3) inhibiting bacterial enolase enzymes reducing acid production.

Question 81: What is the aetiology of dental caries according to the Keyes Circle?

Interaction of three factors: susceptible host (tooth), cariogenic microorganisms (Streptococcus mutans, Lactobacilli), and fermentable substrate (sugars) — all three must be present (Correct answer)
Genetic susceptibility alone
Fluoride deficiency alone
Single bacterial infection without diet involvement

Correct answer: Interaction of three factors: susceptible host (tooth), cariogenic microorganisms (Streptococcus mutans, Lactobacilli), and fermentable substrate (sugars) — all three must be present

The Keyes model (later expanded to include time) describes caries as arising from the interaction of susceptible tooth surfaces, cariogenic bacteria, and dietary fermentable carbohydrates over time.

Question 82: What anatomical structure separates the anterior and posterior cranial fossae?

The cribriform plate of the ethmoid
The lesser wing of the sphenoid and the petrous part of the temporal bone (forming the floor boundaries) (Correct answer)
The occipital bone
The frontal ridge

Correct answer: The lesser wing of the sphenoid and the petrous part of the temporal bone (forming the floor boundaries)

The boundary between the anterior and middle cranial fossae is formed by the lesser wing of the sphenoid and the anterior clinoid processes. This is relevant in dental anatomy when understanding skull base relationships.

Question 83: What is 'burning mouth syndrome' (BMS) and how is it managed?

A sign of oral cancer requiring biopsy
Chronic burning oral pain without identifiable organic cause — predominantly in post-menopausal women; managed with cognitive-behavioural therapy, clonazepam, alpha-lipoic acid, and amitriptyline (Correct answer)
Treated exclusively with antifungal therapy
Caused by denture pressure and managed by denture adjustment

Correct answer: Chronic burning oral pain without identifiable organic cause — predominantly in post-menopausal women; managed with cognitive-behavioural therapy, clonazepam, alpha-lipoic acid, and amitriptyline

BMS is a chronic neuropathic pain condition with no identifiable cause, affecting tongue/lips/palate. Management includes reassurance, CBT, low-dose clonazepam topically, alpha-lipoic acid, and tricyclic antidepressants. Ruling out organic causes (candida, nutritional deficiency, diabetes) is essential.

Question 84: Which type of hypersensitivity reaction is most commonly associated with local anaesthetic allergy in dentistry?

Type III (immune complex)
Type II (cytotoxic)
Type IV (delayed/contact) (Correct answer)
Type I (immediate/anaphylaxis)

Correct answer: Type IV (delayed/contact)

True allergy to local anaesthetics is extremely rare, but when it occurs with amide-type agents, it is most commonly a Type IV delayed hypersensitivity reaction (contact dermatitis). Type I anaphylactic reactions are more associated with ester-type local anaesthetics and preservatives.

Question 85: A patient presents 3 days post-extraction with severe throbbing pain, a foul taste, and an empty socket with exposed bone. What is the diagnosis?

Osteomyelitis
Residual root fracture
Alveolar osteitis (dry socket) (Correct answer)
Normal post-extraction healing

Correct answer: Alveolar osteitis (dry socket)

Alveolar osteitis (dry socket) typically presents 2–5 days after extraction with severe pain, halitosis, and an empty socket where the blood clot has been lost or lysed. Risk factors include smoking, oral contraceptive use, and traumatic extraction. Management involves irrigation and placement of an obtundent dressing.

Question 86: A patient taking metronidazole for a dental infection should be warned about interaction with which substance?

Grapefruit juice
Alcohol (Correct answer)
Caffeine
Dairy products

Correct answer: Alcohol

Metronidazole inhibits aldehyde dehydrogenase, causing a disulfiram-like reaction when alcohol is consumed. Patients experience nausea, vomiting, flushing, and tachycardia. Patients should be advised to avoid alcohol during treatment and for 48 hours after completing the course.

Question 87: Which antibiotic is the first-line choice for acute dental infection in a penicillin-allergic patient in the UK?

Erythromycin
Clindamycin
Ciprofloxacin
Metronidazole (Correct answer)

Correct answer: Metronidazole

According to the BNF and FGDP guidelines, metronidazole 400mg three times daily for 5 days is the first-line alternative for acute dental infections when amoxicillin cannot be used due to penicillin allergy. It is effective against the predominantly anaerobic flora of dental abscesses.

Question 88: What is the definition of 'nociceptive pain' versus 'neuropathic pain'?

Neuropathic pain only affects the trigeminal nerve
Nociceptive: pain arising from tissue damage activating nociceptors (normal protective function); Neuropathic: pain arising from damage or dysfunction of the somatosensory nervous system itself (Correct answer)
Nociceptive pain is always acute; neuropathic pain is always chronic
They are synonymous — both describe tooth pain

Correct answer: Nociceptive: pain arising from tissue damage activating nociceptors (normal protective function); Neuropathic: pain arising from damage or dysfunction of the somatosensory nervous system itself

Nociceptive pain (e.g., from dental pulpitis, infection) results from activation of specialised pain receptors responding to tissue damage. Neuropathic pain (e.g., trigeminal neuralgia, PDAP) arises from abnormal processing in the pain pathway itself.

Question 89: What is the recommended minimum distance the operator should stand from the X-ray tube head during exposure?

Distance only matters for panoramic equipment
No minimum distance if wearing a lead apron
0.5 metres is sufficient
At least 1.5–2 metres away, outside the primary beam, ideally behind a lead screen or wall (Correct answer)

Correct answer: At least 1.5–2 metres away, outside the primary beam, ideally behind a lead screen or wall

Operators should stand at least 1.5–2 metres from the tube head, outside the primary beam (not at 90° to it), and ideally behind a structural barrier during dental X-ray exposures.

Question 90: What is the rationale for prescribing dexamethasone before lower third molar surgery?

To prevent dry socket
To reduce anaesthetic requirements
To treat infection preoperatively
Prophylactic corticosteroid reduces post-operative trismus, swelling, and pain by suppressing inflammatory mediators before surgical trauma occurs (Correct answer)

Correct answer: Prophylactic corticosteroid reduces post-operative trismus, swelling, and pain by suppressing inflammatory mediators before surgical trauma occurs

Pre-operative dexamethasone (4–8 mg IM or IV) reduces post-surgical trismus, facial swelling, and pain by pre-emptively suppressing the inflammatory cascade. It is used in third molar surgery and other oral surgical procedures.

Question 91: What is the pharmacological management of post-herpetic neuralgia (PHN) affecting the trigeminal nerve?

Amitriptyline (TCA), gabapentin/pregabalin (calcium channel modulators), lidocaine patches, or capsaicin cream — NICE-recommended neuropathic pain treatments (Correct answer)
NSAIDs as first-line
Surgical decompression as first-line
Penicillin antibiotic therapy

Correct answer: Amitriptyline (TCA), gabapentin/pregabalin (calcium channel modulators), lidocaine patches, or capsaicin cream — NICE-recommended neuropathic pain treatments

PHN (persisting pain after herpes zoster/shingles) affecting the trigeminal distribution is managed with NICE-recommended neuropathic pain agents: amitriptyline, gabapentin or pregabalin, topical lidocaine, or capsaicin 8% patch.

Question 92: A patient taking a selective serotonin reuptake inhibitor (SSRI) attends for dental treatment. Which drug interaction is most relevant in dentistry?

Reduced efficacy of local anaesthetic
Increased bleeding risk due to impaired platelet function (Correct answer)
Increased risk of cardiac arrhythmia
Hypertensive crisis with adrenaline-containing LA

Correct answer: Increased bleeding risk due to impaired platelet function

SSRIs inhibit serotonin reuptake into platelets, impairing platelet aggregation and increasing bleeding risk, particularly when combined with other antiplatelet agents or NSAIDs. Dentists should be aware of prolonged bleeding times and exercise caution during surgical procedures.

Question 93: What is the primary mineral component of dental enamel?

Calcium carbonate
Fluorapatite
Hydroxyapatite (Correct answer)
Tricalcium phosphate

Correct answer: Hydroxyapatite

Dental enamel is composed of approximately 96% inorganic material by weight, primarily in the form of hydroxyapatite crystals (Ca10(PO4)6(OH)2). These crystals are organised into enamel rods, making enamel the hardest biological tissue in the human body.

Question 94: What radiation dose does a lateral cephalometric radiograph deliver compared to a periapical?

Same as a chest X-ray (0.1 mSv)
Less than 0.1 µSv — negligible
Cephalometric radiograph delivers approximately 2–5 µSv — similar to or slightly higher than a single periapical (1–8 µSv) (Correct answer)
10 times more than a full mouth periapical series

Correct answer: Cephalometric radiograph delivers approximately 2–5 µSv — similar to or slightly higher than a single periapical (1–8 µSv)

A lateral skull cephalometric radiograph delivers approximately 2–5 µSv effective dose, comparable to a small number of intraoral periapical radiographs. This relatively low dose supports its use in orthodontic treatment planning.

Question 95: What assessment tool is used to screen for depression and anxiety in patients with chronic orofacial pain?

DVLA driving fitness assessment
PHQ-9 (Patient Health Questionnaire) for depression; GAD-7 for anxiety — recommended in chronic pain assessment (Correct answer)
OHIP-14 (Oral Health Impact Profile)
Visual Analogue Scale for pain only

Correct answer: PHQ-9 (Patient Health Questionnaire) for depression; GAD-7 for anxiety — recommended in chronic pain assessment

Validated psychiatric screening tools (PHQ-9 for depression, GAD-7 for anxiety) are recommended in chronic orofacial pain management because psychological comorbidity significantly impacts pain experience and treatment outcomes.

Question 96: Which type of white blood cell is most increased in a bacterial infection?

Neutrophils (Correct answer)
Lymphocytes
Eosinophils
Basophils

Correct answer: Neutrophils

Neutrophils are the primary phagocytic cells of the innate immune system and are the first responders to bacterial infection. A raised neutrophil count (neutrophilia) on a full blood count is a hallmark of acute bacterial infection. Lymphocytosis, in contrast, is more associated with viral infections.

Question 97: What is the recommended interval for routine bitewing radiographs in a high-caries-risk adult patient?

Every 6 months (Correct answer)
Every 12 months
Only when clinically indicated
Every 24 months

Correct answer: Every 6 months

FGDP(UK) Selection Criteria for Dental Radiography recommends posterior bitewing radiographs at 6-monthly intervals for high-caries-risk adults. For moderate risk, the interval is 12–18 months, and for low risk, 24 months. This is based on the expected rate of caries progression.

Question 98: What is the purpose of the 'curve of Spee'?

A measure of curve in the condylar path
A classification of malocclusion severity
A naturally occurring anteroposterior curve of the occlusal plane facilitating efficient chewing and distributing occlusal forces (Correct answer)
A measurement of overjet

Correct answer: A naturally occurring anteroposterior curve of the occlusal plane facilitating efficient chewing and distributing occlusal forces

The Curve of Spee is the anteroposterior curvature of the dental occlusal plane (when viewed from the side). It reduces shear forces during function and is important in prosthodontic planning.

Question 99: At the molecular level, polymerisation shrinkage in composite resins occurs because:

Van der Waals intermolecular distances are replaced by shorter covalent bond lengths as monomers link (Correct answer)
Heat generated during curing causes thermal contraction of the polymer
Water sorption into the matrix displaces residual monomer causing collapse
Inorganic filler particles contract under high-intensity light exposure

Correct answer: Van der Waals intermolecular distances are replaced by shorter covalent bond lengths as monomers link

As free monomers (separated by Van der Waals gaps of ~3.5 Å) polymerise into a chain, covalent C-C bonds (~1.54 Å) replace the larger intermolecular distances, causing 1–5% volumetric shrinkage.

Question 100: How many cusps does a maxillary first molar typically have?

4 cusps (with a 5th Cusp of Carabelli occasionally) (Correct answer)
5 cusps always
6 cusps
3 cusps

Correct answer: 4 cusps (with a 5th Cusp of Carabelli occasionally)

The maxillary first molar has 4 main cusps: mesiobuccal, distobuccal, mesiopalatal (largest), and distopalatal. The Cusp of Carabelli is an accessory cusp on the mesiopalatal cusp, present in about 60% of individuals.

ORE Part 1 Dental Exam

The GDC Overseas Registration Exam Part 1 tests overseas-qualified dentists on clinically applied dental science, human disease, and clinical dentistry subjects required to practise in the UK.

100

Questions

180 min

Time Limit

50%

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