A six-month, double blind, clinical study was conducted to determine the effect on supragingival
calculus formation of a
dentifrice containing 1.30% soluble
pyrophosphate (from 2.0%
tetrasodium pyrophosphate) and 1.50% of a copolymer of methoxyethylene and
maleic acid, as compared to a
dentifrice containing the same amount of soluble
pyrophosphate but without the copolymer. This
pyrophosphate/copolymer
dentifrice contained the optimal ratio of
pyrophosphate anion to copolymer required for obtaining a comparable anticalculus effect to a clinically proven anticalculus
dentifrice containing 3.3% soluble
pyrophosphate and 1.0% of a copolymer. The optimal
pyrophosphate/copolymer ratio was determined by a series of in vitro laboratory and in vivo animal studies. Male and female adult subjects were stratified into three balanced groups according to baseline
calculus scores. They received an oral prophylaxis and were assigned to the use of either the
dentifrice containing soluble
pyrophosphate and the copolymer, or to the
dentifrice containing soluble
pyrophosphate but without the copolymer, or to a placebo
dentifrice that did not contain an anticalculus ingredient. The results of the three-month
calculus examination indicated that the
dentifrice containing soluble
pyrophosphate and the copolymer provided a 33.66% reduction in supragingival
calculus formation after an oral prophylaxis as compared to the placebo
dentifrice. This reduction was statistically significant at the 99 percent level of confidence. The results of the six-month
calculus examination indicated that the
dentifrice containing the soluble
pyrophosphate and the copolymer provided a 36.10% reduction in supragingival
calculus formation after an oral prophylaxis, as compared to the placebo
dentifrice. This reduction was also statistically significant at the 99% level of confidence.(ABSTRACT TRUNCATED AT 250 WORDS)