[Effect of local application of NaF on the content of calcium, phosphorus and fluorine in young dental calculus].

The purpose of the study was determination of changes in the content of calcium, phosphorus and fluorine in young dental calculus developing in vivo in case of not using a rinsing solution of 1% NaF or after its use. The studied material comprised tartar deposited on a foil fastened to the lower incisor in 6 women aged 23-28 years. They were divided into two groups of 3 women in each, one of the groups had a high tendency for mineralization of tartar, while in the other group this tendency was small. The study was carried out in two stages. In the first, control, stage at the time of foil wearing the women rinsed mouth with a placebo solution, in the experimental stage they used 1% sodium fluoride solution for this purpose. The analysis of the superficial distribution of various elements showed a greater density of impulses in the case of calcium and fluorine, and lower density in the case of phosphorus in the deposits formed in the experimental stage as compared to the control stage. Using X-ray microanalysis a statistically significant rise was found of the concentration of calcium and fluorine, and reduced content of phosphorus in the deposits formed after NaF application. The per cent in weight of fluorine in young supragingival tartar from the control stage was 0.2-3.1, while in the experimental stage it rose to 3.0-27.7. The statistical analysis showed that the rise of fluorine content in tartar in cases with low tendency for mineralization of tartar (group II) was statistically significantly higher than in the group with a high tendency for tartar development (group I). The Ca/F ratio calculated on the basis of the results in the control stage was 1.35 to 2.68. After application of fluoride rinsing solution this value rose to 1.96 to 4.34 in the studied women.