Chapter 07: Preventive and Desensitizing Materials

Chapter 07: Preventive and Desensitizing Materials

Complete Chapter Questions With Answers

Sample Questions Are Posted Below

MULTIPLE CHOICE

1. The accepted optimal level of fluoride in the drinking water is in the range of ____ mg/L or parts per million.

ANS:  D

The accepted optimal level of fluoride in the drinking water is in the range of 0.7 to 1.2 mg/L or parts per million. Consumption of excess fluoride during formation of the teeth may lead to a condition known as fluorosis. Severe fluorosis can cause brown staining and pitting of the enamel surface.

REF:   p. 97               TOP:   Fluoride

2. Where is fluoride’s greatest anticaries benefit gained?

ANS:  C

Fluoride’s greatest anticaries benefit is gained from topical fluoride exposure after the teeth have erupted. Fluoride in the saliva surrounding the tooth is incorporated into the surface of enamel crystals during remineralization to form a surface veneer containing fluorapatite that has much lower solubility than the original tooth mineral.

REF:   p. 98               TOP:   Fluoride (Topical and Systemic Effects)

3. Which of the following are true concerning fluoride and bacterial inhibition?
4. The fluoride ion freely crosses the bacterial cell wall.
5. Some of the fluoride present in plaque fluid combines with the hydrogen ion of the acid to become hydrofluoric acid.
6. Hydrofluoric acid diffuses into the cell.
7. Once in the acid cytoplasm of the cell, the hydrofluoric acid separates into the fluoride ion and the hydrogen ion.

ANS:  C

Some of the fluoride present in plaque fluid combines with the hydrogen ion of the acid to become hydrofluoric acid, and hydrofluoric acid diffuses into the cell. The fluoride ion, however, has been shown not to cross the bacterial cell wall, and once in the alkaline rather than acid cytoplasm of the cell, the hydrofluoric acid separates into the fluoride ion and the hydrogen ion again. These ions disrupt the enzyme activities essential to the functioning of bacteria and cause their death.

REF:   p. 98               TOP:   Fluoride (Bacterial Inhibition)

4. Which of the following is the most commonly noted side effect of the use of chlorhexidine gluconate as an antibacterial mouth rinse?

ANS:  B

Brown stain may form on the teeth and tongue; on glass ionomer, compomer, and composite restorations; and on artificial teeth. Chlorhexidine gluconate has a bitter taste and may affect the taste of some foods. Staining seems to be more rapid in some individuals. Diet and brushing habits are thought to play an important role in how rapidly staining occurs.

REF:   p. 98

TOP:   Fluoride (Fluoride and Antibacterial Rinses for the Control of Dental Caries)

5. Which of the following is true concerning in-office fluoride application?

ANS:  D

When used one to two times a year, topical fluoride treatments have been shown to produce 20% to 26% caries reduction. The most commonly used fluorides come in the form of topical gels or foams that are applied for 4 minutes in disposable trays. A 1-minute application is not recommended by the ADA. The 1-minute application delivers approximately 85% of the fluoride that a 4-minute application delivers.

REF:   p. 100             TOP:   Fluoride (In-Office Fluoride Applications [Topical])