Cariology I

Question 1

What are the 3 main clinical reasons for losing teeth?

Answer 1

1. Non-restorable cavity
2. Loss of periodontal support
3. Trauma

Question 2

The apatite mineral is lost by these four means:

Answer 2

1. Corrosion
2. Attrition
3. Abrasion
4. Abfraction/fracture

Question 3

The progressive loss, by bacterially-generated acid dissolution, of the apatite composition of the enamel and dentin, or of the cementum and dentin. It is the disease.

Answer 3

Dental Caries

Question 4

The clinically evident result (sign) of the disease. A “hole “ in the tooth caused by the caries process.

Answer 4

Dental cavity

Question 5

These 3 factors are necessary for dental caries to occur:

Answer 5

1. Tooth structure
2. Acidogenic and aciduric bacteria.
3. Fermentable carbohydrate.

Question 6

The velocity of a reaction is proportional to the product of the masses of the reacting substances, each raised to a power equal to the number of molecules taking part.

Answer 6

Ion activity product (IAP)

Question 7

The solubility product constant identifies the equilibrium point of mineral dissolution (point of saturation of the solution) at a specific pH and temperature.

Answer 7

Solubility product constant (KSP)

Question 8

True or false: The higher (larger) the solubility product constant, the more soluble the compound.

Answer 8

True

Question 9

What is the KSP of hydroxyapatite at a pH of 6 and at 37 degrees?

Answer 9

7.41 x 10 ^ -60 mol/l

Question 10

When is a solution in equilibrium?

Answer 10

When IAP=KSP

Question 11

When will dissolution of a mineral occur (demineralization)?

Answer 11

When IAP < KSP

Question 12

When will the solution be supersaturated with respect to the mineral, and mineral formation occur (remineralization)?

Answer 12

When IAP > KSP

Question 13

Why is enamel solubility increased by acid?

Answer 13

The more H + ions, the more molecules you take away from equation. This causes other minerals to dissolve more to reach equilibrium.

Question 14

The pH at which a supersaturated solution becomes just saturated with respect to the mineral.

Answer 14

Critical pH

Question 15

What is the critical pH of hydroxypatite?

Answer 15

5.5

Question 16

The excess of one ion in solution requires less of the other ions in solution to attain the KSP.

Answer 16

Common ion effect.

Question 17

If you add Ca or PO4 to a solution, would this increase or decrease the amount of hydroxyapatite that dissolves?

Answer 17

decrease

Question 18

What are the 3 most common types of apatite crystals that compose enamel?

Answer 18

1. Carbonated hydroxyapatite (CAP)
2. Hydroxyapatite (HAP)
3. Fluorhydroxyapatite (FHAP)

Question 19

List the solubilities of apatite types from the most soluble to least.

Answer 19

CAP > HAP > FHAP

Question 20

True or false: Newly erupted teeth dissolve much easier than mature teeth.

Answer 20

True

Question 21

What is the critical pH for CAP?

Answer 21

6.5

Question 22

What is the critical pH of HAP?

Answer 22

5.5

Question 23

True or false: HAP can withstand 10x more acid than Cap.

Answer 23

True

Question 24

What is the critical pH for FAP?

Answer 24

4.8

Question 25

What prevents Excessive remineralization?

Answer 25

Proteins such as tyrosine-rich peptides, statherin coat the pellicle and prevent seeding of apatite crystals.

Question 26

Tartar = _____ cavities, _____ gum disease.

Answer 26

Fewer

More

Question 27

If you apply a fluoride product to the teeth, is there a greater fluoride uptake in plaque covered teeth or on “clean” teeth?

Answer 27

Plaque covered because of the lower pH.