Dental Calculus Composition. 2. Subgingival Calculus: Ash, Calcium, Phosphorus, and Sodium

Abstract

Subgingival cal-culus, obtained by deep scaling (marginal subgingival) and during gingivectomy (deep subgingival), was analyzed for loss in weight on ashing (900[degree]C), as well as Ca, P, and Na content. The mineral content of marginal subgingival calculus was quite variable. Deep subgmgival calculus had a consistently high mineral content with a mean Ca: P ratio (weight) of 2.04 as compared to 1.89 for marginal calculus. The mean Na content of ashed marginal calculus (1.87%) was considerably lower than that of deep calculus (3.11%). The composition of deep subgingival calculus was related to the location in the mouth. Marginal deposits from the upper molar areas had a lower mineral content than those from the lower lingual areas, except in subjects with subgingival calculus in 1 or the other area but not in both. In those subjects, the lower lingual calculus had a lower mineral content.