NBDE Knowledge 4

Question 1

Which of the following is the primary buffer system in saliva?

Accepted Answer

Bicarbonate-carbonic acid system

Answer

The bicarbonate-carbonic acid system is the dominant salivary buffer, especially at high flow rates, neutralizing acids produced by oral bacteria.

Question 2

The cell-rich zone of Höhl in the dental pulp is located:

Accepted Answer

Immediately beneath the cell-free zone

Answer

The cell-rich zone of Höhl lies immediately beneath the acellular cell-free zone of Weil and contains fibroblasts and undifferentiated mesenchymal cells.

Question 3

Which landmark is used to locate the mental foramen during a mental nerve block?

Accepted Answer

Between the first and second mandibular premolars

Answer

The mental foramen is typically located between the apices of the first and second mandibular premolars, slightly below the apices.

Question 4

Which histologic feature is pathognomonic of ameloblastoma?

Accepted Answer

Stellate reticulum-like cells within follicles lined by palisaded columnar cells

Answer

Ameloblastoma mimics the enamel organ with peripheral palisaded columnar cells and a central stellate reticulum pattern in follicular arrangements.

Question 5

During mandibular development, Meckel's cartilage primarily:

Accepted Answer

Serves as a template that is later replaced by intramembranous ossification

Answer

Meckel's cartilage acts as a scaffold alongside which the mandible forms by intramembranous ossification; the cartilage itself mostly disappears.

NBDE - National Board Dental Examination Practice Test

NBDE - National Board Dental Examination Practice Test

NBDE Knowledge 4