Comparative Study of Carious Lesions in Shark and Human Enamel

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Why does caries progress slowly in enamel?

Dentin is more susceptible to caries
Presence of fluoride in saliva
High supersaturation of saliva with respect to enamel mineral (correct)
Enamel is composed chiefly of hydroxyapatite

Which type of apatite crystal is more resistant to acid?

F fluoroapatite (correct)
Calcium-deficient carbonated hydroxyapatite
OH hydroxyapatite
Hydroxyapatite with high fluoride content

What is the role of fluoride in enamel resistance to caries?

Aids in the formation of enamel crystals (correct)
Increases dentin susceptibility to caries
Reduces supersaturation of saliva
Decreases enamel mineral solubility

What is the solubility product of enamel required for the formation of enamel crystals?

$5.5 \times 10^{-55}$ mol/l (C) Signup and view all the answers

Which type of enamel has a higher concentration of fluoride, human or shark enamel?

Shark enamel (A) Signup and view all the answers

Under physiological conditions, why doesn't enamel mineral dissolve in saliva?

$IAPHA > KSPenamel$ (B) Signup and view all the answers

What forms on the surface of fluorapatite when calcium and fluoride ions are released during initial dissolution?

Calcium Fluoride (CaF2) (B) Signup and view all the answers

What effect does repeated exposure to fluoride have on enamel over time?

Increased resistance to acid attack (D) Signup and view all the answers

Which compound is more acid resistant than Hydroxyapatite (HA)?

Fluorapatite (A) Signup and view all the answers

What ions replace carbonate ions in the apatite structure during increased posteruptive maturation?

Fluoride ions (B) Signup and view all the answers

What process involves the deposition of Fluoride, Calcium, Phosphate, and Hydroxyl ions?

Remineralization Process (D) Signup and view all the answers

How does Fluoridated Hydroxyapatite (FHA) protect enamel against acid attack?

By forming compact and regular crystals like Hydroxyapatite (B) Signup and view all the answers

How does the carbonate content of apatite crystals impact stability and solubility?

Apatite crystals with low carbonate contents are more stable and less soluble. (D) Signup and view all the answers

What is the role of fluoride in the remineralization process of enamel?

Fluoride enhances remineralization by facilitating the re-precipitation of calcium and phosphate ions. (D) Signup and view all the answers

How does fluoride affect the activity of oral streptococci?

Fluoride inhibits enolase and ATP-ase activity, reducing acid production by streptococci. (A) Signup and view all the answers

What effect does fluoride have on tooth morphology when administered during tooth formation?

Fluoride results in shallower fissures and more rounded cusps. (B) Signup and view all the answers

How does fluoride concentration in saliva or plaque relate to its inhibitory effects on bacteria?

Concentrations above 1 ppm are needed for fluoride to inhibit bacteria activity. (B) Signup and view all the answers

What is the impact of fluoride on reducing growth in bacteria?

10 ppm of fluoride is required for reducing growth in bacteria. (A) Signup and view all the answers