Anticalculus efficacy of a dentifrice containing potassium nitrate, soluble pyrophosphate, PVM/MA copolymer, and sodium fluoride in a silica base: a twelve-week clinical study.

A randomized, two-compartment calculus clinical study of twelve-weeks duration was conducted among a group of calculus-forming subjects in the St. Louis area. The purpose of this parallel and double-blind clinical study was to compare the effect of a dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer and 0.243% sodium fluoride in a silica base, to that of a placebo dentifrice, with regard to supragingival calculus formation. The study examiner, using the Volpe-Manhold Calculus Index, selected a panel of calculus-prone men and women who had completed a one-month placebo regimen. The Volpe-Manhold Calculus Index scores and the number of completely calculus-free sites were recorded. One-hundred and fifteen subjects were entered into the study. After an oral soft and hard tissue examination, the subjects were given a complete oral prophylaxis and randomly assigned to use either the placebo or test dentifrice for a 12-week home-use period. They were prohibited from using any other means of oral hygiene during the study. After completing 12 weeks of twice-daily brushing at home using their assigned toothpaste and a standard soft-bristled toothbrush, subjects were again assessed for supragingival calculus deposits and calculus-free sites. The dentifrice containing 5.0% potassium nitrate, 1.3% soluble pyrophosphate, 1.5% PVM/MA copolymer and 0.243% sodium fluoride in a silica base, inhibited supragingival calculus formation by 54.4%, as compared to a 0.243% sodium fluoride silica-based placebo dentifrice. The mean Volpe-Manhold Calculus Index scores were compared statistically and the difference indicated statistical significance at probability of 0.01 by means of an analysis of covariance (ANCOVA). The number of calculus-free sites, a second parameter of efficacy, also was compared and demonstrated an absolute difference of 32.6% in favor of the group using the dentifrice containing potassium nitrate, soluble pyrophosphate and PVM/MA copolymer compared to a placebo dentifrice (37.8% vs 5.2%, respectively). An analysis of covariance indicated that this improvement showed statistical significance at a probability of 0.01.