Doctor of Dental Surgery MCQ Flashcards

Which tooth surface is most susceptible to root caries in the elderly population?

Answer: Buccal surface below the CEJ

Exposed root surfaces, especially buccal surfaces below the CEJ, are most susceptible to root caries due to gingival recession common in elderly patients.

Which tooth movement produces the greatest amount of root resorption during orthodontic treatment?

Answer: Intrusion

Intrusive tooth movement produces the greatest root resorption because it concentrates force at the root apex.

A removable partial denture major connector for a mandibular arch should be located:

Answer: At least 3–4 mm from the gingival margins

Mandibular major connectors must be placed at least 3–4 mm from the gingival margins to avoid impingement on gingival tissues.

Which periodontal fiber group is responsible for resisting intrusive forces on the tooth?

Answer: Oblique fibers

Oblique fibers, the most numerous PDL fibers, run from cementum in a coronal direction to alveolar bone and primarily resist intrusive (axial) forces.

Zinc oxide eugenol temporary cement should NOT be used under which type of restoration?

Answer: Composite resin restorations

Eugenol inhibits the polymerization of composite resin, so ZOE cements are contraindicated as bases or temporaries under composite restorations.

Which local anesthetic has the longest duration of action among those used in dentistry?

Answer: Bupivacaine

Bupivacaine (Marcaine) has the longest duration of action, providing pulpal anesthesia for up to 90 minutes and soft-tissue anesthesia for 4–9 hours.

A patient develops trismus after an inferior alveolar nerve block. The most likely cause is:

Answer: Hematoma formation in the medial pterygoid muscle

Trismus after an IAN block most commonly results from hematoma or direct trauma to the medial pterygoid muscle from the needle.