[Clinical study of the anti-calculus effect of a dentifrice containing sodium polyphosphate]

A double-blind clinical study was conducted to evaluate the effect of a tartar-control dentifrice containing 1% sodium polyphosphate as tartar control agent compared with dentifrice A containing 5% sodium pyrophosphate and a placebo dentifrice. One hundred forty-eights who continued to have a degree of calculus formation after using a regular dentifrice containing no tartar control agent for 1 month in the pretest, were stratified randomly on the basis of pretest, calculus score, age and sex into 3 homogeneous groups. All subjects who received initial prophylaxis were provided the assigned dentifrice and toothbrush. No instructions regarding frequency or method of toothbrushing were allowed. Assessment of supragingival calculus was made at 4 and 12 weeks using the calculus scoring procedure proposed by Volpe et al. Side effects such as oral irritation, ablation of oral mucosa and discoloration of teeth caused by dentifrices were also diagnosed after 12 weeks of use. The following results were obtained in this study. 1. The test dentifrice had reduced (P less than 0.01) supra-gingival calculus significantly more than dentifrice A and the placebo at 12 weeks. 2. A significant reduction (P less than 0.01) was observed when dentifrice A was compared with the placebo dentifrice. 30.1% reduction was obtained using the test dentifrice and 9.0% reduction using dentifrice A when assessed in subjects who had a pretest VMI score of more than 6.0. 3. No side effects caused by the dentifrice which contained sodium polyphosphate were observed.