NBDE Trivia 4

Question 1

Which periodontal fiber group runs from the alveolar crest obliquely to the cementum in an apical direction?

Accepted Answer

Oblique fibers

Answer

Oblique fibers are the most numerous PDL fibers, running from alveolar bone coronally to insert into cementum, resisting axial forces.

Question 2

Which radiographic technique provides the most accurate image of the true mesiodistal width of interproximal bone loss?

Accepted Answer

Bitewing radiograph

Answer

Bitewing radiographs show the crestal bone of both arches with minimal distortion, making them optimal for assessing interproximal bone levels.

Question 3

In operative dentistry, a beveled cavosurface margin is indicated for which restorative material?

Accepted Answer

Cast gold

Answer

Beveled cavosurface margins increase the surface area of the gold-tooth interface and improve marginal seal for cast gold restorations.

Question 4

Which immunoglobulin class is predominant in saliva and provides the first line of mucosal defense?

Accepted Answer

IgA (secretory)

Answer

Secretory IgA (sIgA) is the predominant antibody in saliva, resisting proteolysis and neutralizing pathogens on mucosal surfaces.

Question 5

The Koplik spots seen in measles are pathognomonic lesions found on which oral surface?

Accepted Answer

Buccal mucosa opposite the lower molars

Answer

Koplik spots appear as small white papules on the buccal mucosa near the lower molars and precede the skin rash of measles.

NBDE - National Board Dental Examination Practice Test