Calculus And Other Etiological Factors Including Food Impaction
Write short note on dental calculus.
Or
Write short answer on calculus.
Answer. Dental calculus is an adherent, calcified or calcifying mass that forms on the surfaces of teeth and dental appliances:
Dental Calculus Types
Depending upon the position of calculus in relation to marginal gingiva it is classified as:
- Supragingival calculus: It is a tightly adherent calcified deposit that forms on the clinical crown of teeth above free gingival margin. It is clinically visible.
- Subgingival calculus: It is that calcific deposit which is formed on root surfaces below free marginal gingiva. It is believed to be formed from gingival exudates and is called seruminal calculus.
Dental Calculus Structure
- Deposits of supragingival calculus are whitish yellow in color and get stained by tobacco or food pigments, while the subgingival calculus is dark brown or greenish black in color.
- The consistency is hard and clay like of supragingival plaque and in subgingival it is hard and film.
- The supragingival plaque is most abundant on lingual surfaces of lower anterior teeth, opposite Wharton’s duct, Bartholin’s duct and buccal aspect of maxillary molars opposite the stenson’s duct.
Read And Learn More: Periodontics Question And Answers
Dental Calculus Composition
Inorganic Components
Component Dry weight (in%)
Inorganic 70–90
Calcium 27–29
Phosphorus 16–18
Carbonate 2–3
Sodium 1.5–2.5
Magnesium 0.6–0.8
Fluoride 0.003–0.04
Crystal forms
Hydroxyapatite 58
Magnesium whitlockite 21
Octacalcium phosphate 12
Brushite 9
Dental Calculus Organic Components
Component Dry weight (in%)
Mixture of protein-polysaccharide 1.9-9.1
complex, desquamated epithelial cells,
leukocytes and various microorganisms
Carbohydrate (consists of glucose, galactose, rhamnose, mannose)
Proteins 5.9-8.2
Lipids 0.2
Dental Calculus Formation
- Calculus is formed by precipitation of mineral salts, which can start between 1st and 14th day of plaque formation.
- In two days plaque can be 50% mineralized and 60 to 90% get mineralized in 12 days.
- calcification starts in separate foci on the inner surface of plaque. These foci of mineralization gradually, increase in size and coalesce to form solid mass of calculus.
- Calculus formation continues until it reaches maximum level in about 10 weeks and 6 months, after where there is decline in its formation, due to mechanical wear from food and lips, cheeks and tongue. This decline is called as reversal phenomenon.
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