Zn concentration of human subgingival calculus related to F, Mg and Cu contents

F and Zn content of human subgingival calculus was studied with respect to its Ca, Mg, Cu, Fe and Ph contents. The material consisted of 60 subgingival calculus samples from 60 persons. The element concentrations were determined with an atomic absorption spectrophotometer except for the F content, which was measured with an ion-selective electrode. The data were analyzed using the multiple linear regression analysis. 24% of F content was explained by Zn and none of the other elements were significantly related to F content. Altogether, 55.4% of Zn content was accounted for in all variables. The selected variables after the removal of nonsignificant ones explained 54.8%. The most important variable was F (24.0%) and the explanation power of Cu was 18.3% and of Mg 12.5%. The regression coefficients of these variables were positive. The mean +/- s.d. concentration of F in the samples was 221.2 +/- 174.1 micrograms/g and of Zn 498.6 +/- 499.1 micrograms/g, respectively.