Concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus

The concentrations of Ca, Mg, Mn, Sr and Zn in supra- and subgingival calculus collected from mandibular anterior teeth mainly of the same persons were analyzed with atomic absorption spectrophotometry. The results showed highly significantly (P less than 0.001) greater Zn and Sr concentrations in subgingival samples. The mean value of Zn was 5.4 times higher in subgingival calculus than in supragingival calculus. In contrast, the concentration of Mn was significantly (P less than 0.01) higher in supragingival calculus. The difference in the concentration of Mg in supra- and subgingival calculus was highly significant (P less than 0.001) only when samples from the same person were compared. The concentration of Ca was very similar in both types of calculus and individual variations were very small.