NBDHE Test Dental Hygiene MCQ 1

Question 1

Which type of tooth deposit is considered the primary etiologic factor in periodontal disease?

Accepted Answer

Dental plaque biofilm

Answer

Dental plaque biofilm is the primary etiologic factor in periodontal disease because it harbors the pathogenic bacteria that trigger the host inflammatory response leading to tissue destruction. Calculus is a secondary factor that retains plaque but is not itself the initiating agent.

Question 2

When exposing a periapical radiograph using the paralleling technique, the image receptor should be placed:

Accepted Answer

Parallel to the long axis of the tooth with a beam directed perpendicular to both

Answer

The paralleling technique requires the image receptor to be parallel to the long axis of the tooth, with the central ray directed perpendicular to both the tooth and the receptor. This minimizes geometric distortion and produces the most dimensionally accurate image.

Question 3

A patient asks how long they should brush their teeth. The evidence-based recommendation for toothbrushing time is:

Accepted Answer

2 minutes

Answer

Two minutes is the evidence-based recommended brushing time endorsed by the American Dental Association. Studies show most people brush for less than one minute, which is insufficient for thorough plaque removal from all tooth surfaces.

Question 4

Which instrument is specifically designed for root planing and is characterized by a rounded back and toe?

Accepted Answer

Area-specific curette

Answer

Area-specific curettes (Gracey curettes) are designed specifically for root planing with a rounded back and toe that allow safe adaptation to root surfaces without trauma to soft tissue. Their offset blade angle makes them ideal for subgingival instrumentation at specific tooth surfaces.

Question 5

Fluoride works primarily to prevent dental caries by:

Accepted Answer

Incorporating into the hydroxyapatite crystal structure to form fluorapatite, which is more acid resistant

Answer

Fluoride prevents caries mainly by incorporating into tooth enamel during remineralization, forming fluorapatite, which is significantly more resistant to acid dissolution than the original hydroxyapatite. It also has some antibacterial properties and can enhance remineralization, but structural incorporation is its primary mechanism.

NBDHE Test Practice Test

NBDHE Test Practice Test

NBDHE Test Dental Hygiene MCQ 1