What is calculus?
mineralised bacterial plaque
Why is calculus potenitally harmful?
- it accumulates more plaque against the gingivae
- very porous and may harbour harmful toxins
What are the 2 type of plaque?
Supra and sub gingival
Where is supragingival calculus commonly found?
above the GM: - near the exit ducts of major salivary glands - lingual of lower anteriors - buccal of upper molars but can form anywhere
What does supragingival calculus look like?
creamy white but can be stained
What % of supragingival calculus is organic and inorganic?
70% inorganic
30% organic
Where does supragingival calculus derive its mineral salts?
Saliva
Where is subgingival calculus commonly found?
below GM but can be above if recession present
- interproximal spaces
- lingual surfaces > buccal
What does subgingival calculus look like?
dark in colour - picks up pigment from blood
What % of subgingival calculus is organic and inorganic?
80-90% inorganic
10-20% organic
Where does subgingival calculus derive its mineral salts?
Crevicular fluid exudate in pockets
What are the 3 methods of calculus attachment?
Acquired pellicle
Irregularities to tooth surface
Direct penetration of microorganisms to cementum
