Mixed Deck — All NBDE Topics Flashcards

In a patient with poorly controlled hypertension, the maximum recommended epinephrine dose per dental appointment is:

Answer: 0.018 mg (2 cartridges of 1:100,000)

The AHA recommends limiting epinephrine to 0.04 mg (approximately two cartridges of 1:100,000) per appointment in patients with significant cardiovascular disease or uncontrolled hypertension.

What is the primary goal of scaling and root planing in the treatment of periodontitis?

Answer: Removal of calculus and bacterial biofilm to reduce inflammation

Scaling and root planing aims to remove calculus and bacterial biofilm from root surfaces to reduce periodontal inflammation and promote tissue healing.

Which of the following clinical scenarios is most indicative of a primary periodontal lesion with secondary endodontic involvement?

Answer: A vital tooth with generalized severe bone loss and a wide, conical periodontal pocket.

A primary periodontal lesion begins with marginal periodontitis. This would be characterized by generalized bone loss and wide pocketing around a tooth that initially tests vital. The infection can then progress apically to involve the pulp via lateral canals or the apical foramen, causing a secondary endodontic lesion where the pulp becomes necrotic. A deep, isolated pocket on a non-vital tooth suggests a primary endodontic lesion draining coronally.

Which local anesthetic has the LONGEST duration of action for dental nerve blocks?

Answer: Bupivacaine 0.5%

Bupivacaine has the longest duration of action among dental local anesthetics, providing 4–12 hours of pulpal anesthesia with a vasoconstrictor.

Which disease is characterized by necrosis of the marginal gingival tissue and interdental papillae?

Answer: Necrotizing periodontal disease

Necrotizing periodontal disease (NPD), including Necrotizing Ulcerative Gingivitis (NUG), is specifically characterized by the rapid onset of necrosis and ulceration of the gingival margins and interdental papillae. This leads to the classic "punched-out" appearance of the papillae, often accompanied by pain, bleeding, and a distinctive fetid odor. Other forms of periodontal disease do not primarily present with tissue necrosis as a defining feature.

In adolescents, when minor fractures occur to the permanent teeth, it is prudent to use which type of restoration?

Answer: Composite resin restorations

Composite resin restorations are the preferred choice for minor fractures in permanent teeth of adolescents due to their conservative nature and excellent aesthetics. They bond directly to the tooth structure, preserving maximum natural tooth tissue, which is crucial for young permanent teeth that may still have large pulp chambers. Other options like full crowns are more aggressive, and amalgam is less aesthetic.

When planning crown lengthening surgery to expose adequate tooth structure, what minimum biological width must be re-established between the restorative margin and the alveolar crest?

Answer: 2.0–3.0 mm

The biologic width (junctional epithelium + connective tissue attachment) averages approximately 2 mm; a restorative margin must maintain at least 2–3 mm from the bone crest to avoid violation.

Which of the following describes a G.V. Black Class II carious lesion?

Answer: Caries on the proximal surface of a posterior tooth

According to G.V. Black's classification system, a Class II lesion is defined as caries affecting the proximal (mesial or distal) surfaces of posterior teeth (premolars and molars).

A patient taking a monoamine oxidase inhibitor (MAOI) requires local anesthesia. Which vasoconstrictor is CONTRAINDICATED?

Answer: Levonordefrin

Levonordefrin (neo-cobefrin) is a sympathomimetic whose pressor effects are dangerously potentiated by MAOIs, risking hypertensive crisis.

Caries can be successfully diagnosed and treated by:

Answer: Good patient history, complete clinical evaluation, radiographic analysis, and comprehensive risk assessment

A thorough diagnosis and effective treatment plan for dental caries require a multi-faceted approach. This includes gathering a good patient history to understand risk factors, performing a complete clinical evaluation to visually and tactilely assess tooth surfaces, utilizing radiographic analysis to detect interproximal or hidden lesions, and conducting a comprehensive risk assessment to tailor preventive and restorative strategies.

A patient presents with a fractured maxillary central incisor involving enamel and dentin without pulp exposure. The FIRST step in treatment is:

Answer: Cover exposed dentin with a sedative dressing and reassess pulp vitality

Exposed dentin should be protected and pulp vitality assessed before definitive restoration, as pulpal response can change in the weeks following trauma.

Which nerve is responsible for causing elevation of the soft palate during the swallowing process?

Answer: Vagus nerve

The vagus nerve (Cranial Nerve X) is primarily responsible for the motor innervation of most muscles of the soft palate, including the levator veli palatini. This muscle's contraction elevates the soft palate, which is a critical action during swallowing to seal off the nasopharynx and prevent food or liquid from entering the nasal cavity.

Aspirin irreversibly inhibits cyclooxygenase enzymes. This type of inhibition is best classified as:

Answer: Covalent (irreversible) inhibition

Aspirin acetylates a serine residue on COX via a covalent bond, permanently inactivating the enzyme for the platelet's lifetime.

Nitrous oxide produces analgesia primarily by:

Answer: Stimulating opioid receptors in the central nervous system

Nitrous oxide activates endogenous opioid receptors in the brainstem and spinal cord, contributing to its analgesic and anxiolytic effects.

In dental practice management, the accounts receivable turnover ratio is used to evaluate:

Answer: How efficiently the practice collects payments

Accounts receivable turnover measures how quickly a dental practice collects outstanding patient and insurance balances.

During the preparation of an MOD cavity for a Class II amalgam restoration, the proximal box should be extended faciolingually until:

Answer: The margins are in a self-cleansing area just clear of the adjacent tooth

Proximal margins must extend just beyond the contact area to a self-cleansing zone where instruments can finish margins and caries risk is reduced.

The process of apposition in tooth development refers to:

Answer: Layered deposition of enamel and dentin matrices

Apposition is the stage in tooth development where enamel and dentin matrices are incrementally laid down by ameloblasts and odontoblasts.

During extraction of the maxillary first molar, oroantral communication is a recognized risk primarily because:

Answer: The apices of the roots are in close proximity to the floor of the maxillary sinus

The roots of the maxillary first molar have a close anatomical relationship with the floor of the maxillary sinus, making inadvertent sinus perforation a risk during extraction.

When a dental office uses a collection agency for unpaid bills, which statement is correct?

Answer: Only the minimum necessary information should be provided

Under HIPAA's minimum necessary standard, only the information required for the collection purpose (e.g., name, balance owed) should be disclosed to a collection agency.

A patient presents with a chief complaint of 'cracking sounds' in the jaw and difficulty opening widely. The maximum opening is 28 mm with deviation to the left. What is the most likely diagnosis?

Answer: Anterior disc displacement without reduction on the left

Limited opening with deflection (not deviation correcting at maximum opening) and absence of clicking suggests disc displacement without reduction (closed lock) on the ipsilateral side.