[Tartar and periodontal disease--a cofactor in etiopathogenesis].

Calculus may be considered as an aggregate of calcified deposits or deposits that are going to calcify in the oral cavity. From a topographical point of view calculus is classified in supragingival and subgingival calculus. Calculus is composed by inorganic (70-80%) and organic (20-30%) components. Calculus results from calcification of plaque and epithelial cells exfoliated from oral mucosae. Calcification phenomena (carbonic acid theory) are caused by a rapid fall down of salivary acidity when saliva springs out gland ducts. In fact in the mouth there is a lower pressure of carbon dioxide than in the gland ducts. From this fact results that calcium bicarbonate (dissolvable) becomes calcium carbonate (undissolvable) that forms, starting from nucleating particles, calcium carbonate crystals. Then calculus is one of the most important cofactors in the etiology and pathogenesis of periodontal disease: a) it favors plaque growth and stabilizes it to dental and periodontal tissues; b) it favors retention of food debris and hinders dental cleaning; c) it has endotoxins and lets them free slowly; d) it hinders periodontal recovery. From this study it results that scaling and root planing are one of the first steps in periodontal therapy.