Dental Calculus: Hardened Dental Plaque

Dental plaque is biofilm formed on the surfaces in the mouth and can be removed by brushing. If dental plaque is not removed, it may lead to formation of calculus. 

Dental Calculus forms when plaque becomes hard due to precipitation of mineral salts. It can form above (supragingival) and under (subgingival) the gums. The hardening of plaque starts from 1 to 14 days, sometimes within 4-8 hours. It plays an important role in initiation and progress of periodontal diseases. As it is hard, it is not readily removed by tooth brushing and professional cleaning may be required.