MCQ Flashcards

The canine eminence is formed by the root prominence of which tooth?

Answer: Maxillary canine

The maxillary canine has the longest root in the dentition, creating a prominent bony ridge called the canine eminence on the anterior maxilla.

Which type of hypersensitivity reaction is responsible for allergic contact stomatitis from dental materials?

Answer: Type IV (cell-mediated)

Allergic contact stomatitis is a Type IV delayed hypersensitivity reaction mediated by sensitized T-lymphocytes reacting to haptens from dental materials.

During mandibular nerve block, the needle tip should be positioned adjacent to which structure?

Answer: Mandibular foramen

The inferior alveolar nerve block targets the mandibular foramen on the medial ramus where the inferior alveolar nerve enters the mandibular canal.

A white, non-removable plaque-like lesion of the oral mucosa that cannot be characterized as any other condition is called:

Answer: Leukoplakia

Leukoplakia is a clinical diagnosis of exclusion — a white patch that cannot be scraped off and cannot be identified as another specific lesion, with malignant potential.

The working length in endodontic treatment is measured to:

Answer: The minor constriction (apical constriction)

Working length is established to the apical constriction (minor foramen), typically 0.5–1 mm from the radiographic apex, to preserve the apical seal.

Which enzyme is primarily responsible for initiating caries by metabolizing sucrose to form insoluble glucans?

Answer: Glucosyltransferase

Glucosyltransferase (GTF) from Streptococcus mutans synthesizes insoluble glucans from sucrose, enabling bacterial adhesion and biofilm formation.

In a Class II cavity preparation, the gingival floor should be positioned:

Answer: Apical to the contact area by at least 0.5 mm

The gingival floor must be placed apical to the proximal contact to allow adequate separation for matrix placement and to ensure margins are accessible for finishing.