09/06 - Dental Calculus

Question 1

What is the definition of dental calculus?

Answer 1

mineralized plaque that forms on the surfaces of natural teeth and dental prostheses

Question 2

What are the 2 types of dental calculus? What is the difference between the two?

Answer 2

SUPRAGINGIVAL:
- coronal to gingival margin
- white or white/yellow
- clay-like consistency
- easily detached from tooth surface
- commonly found opposite salivary ducts
SUBGINGIVAL:
- below the gingival margin
- hard, dense
- dark-colored
- extends to the base of pocket but does not reach JE

• with gingival recession, subgingival can become supragingival

Question 3

What are the 4 ways to detect dental calculus?

Answer 3

• tactile exploration
• dental radiographs (not always) (detection of spurs)
• a blast of air to open gingival margins
• color of the overlying gingiva

Question 4

True or false: Calculus is the primary cause of periodontitis.

Answer 4

FALSE. Calculus represents a secondary product of infection and is NOT a primary cause of periodontitis.

Question 5

Clinically, subgingival calculus is the most frequently diagnosed using which one of the following methods:

a. a 5-second blast of air
b. a periapical x-ray
c. an MRI
d. tactile exploration
e. disclosing with erythrosine solution

Answer 5

d. tactile exploration

Question 6

What are the 2 ways calculus attaches to the tooth?

Answer 6

• UNDERLYING PELLICLE: pelllicle calcifies and attaches to cementum, enamel, or dentin
• PENETRATION OF SURFACE IRREGULARITIES: caries, exposed root cementum, previous insertion of Sharpey’s fibers, and root resorption

Question 7

The mineralization of calculus begins in ___.

Answer 7

the bacterial colonies or ECM

Question 8

What are the 4 forms of calcium phosphate?

Answer 8

• CaH(PO4) x 2H2O = brushite (B)
• Ca4H(PO4)3 x 2H2O = octa calcium phosphate (OCP)
• Ca5(PO4)3 x OH = hydroxyapatite (HA)
• beta-Ca3(PO4)2 = whitlockite (W)

Question 9

Which form of calcium phosphate is the basis for supragingival calculus formation and seen in recent (<2 weeks old) calculus?

Answer 9

CaH(PO4) x 2H2O = brushite (B)

Question 10

Which form of calcium phosphate is predominant in exterior layers and forms platelet like crystals?

Answer 10

Ca4H(PO4)3 x 2H2O = octa calcium phosphate (OCP)

Question 11

Which form of calcium phosphate is predominant in inner layers of old calculus and forms rod or sand-grain-like crystals?

Answer 11

Ca5(PO4)3 x OH = hydroxyapatite (HA)

Question 12

Which form of calcium phosphate is most common form in subgingival calculus and has hexagonal crystals?

Answer 12

beta-Ca3(PO4)2 = whitlockite (W)

Question 13

True or false: Calculus is covered by a layer of viable plaque.

Answer 13

true

Question 14

True or false: The roughness of calculus initiates gingivitis.

Answer 14

FALSE. The roughness of calculus does NOT initiate gingivitis.

Question 15

True or false: Calculs impedes oral hygiene measures.

Answer 15

true

Question 16

True or false: Calculus keeps plaque in close proximity to tissues.

Answer 16

true

Question 17

True or false: Calculus is removed due to its plaque retentive nature.

Answer 17

true