A one-year, double-blind clinical study was conducted on a population of Thai children and teenagers to determine the effect of the twice daily use of an anticalculus dentifrice on supragingival calculus formation and gingival recession, as compared to the use of a placebo dentifrice and the continuation of customary oral hygiene procedures. The subjects were initially evaluated for calculus using the Volpe-Manhold procedure and for gingival recession using the GRT procedure of Volpe, Triratana, and Rustogi. All subjects received an oral prophylaxis and were assigned to the use of the following: (1) a placebo dentifrice containing 0.243% sodium fluoride in a silica base, (2) an anticalculus dentifrice containing 1.3% soluble pyrophosphate and 1.5% Gantrez copolymer in a 0.243% sodium fluoride/silica base, or (3) continuation of customary oral hygiene procedures. After six months, the subjects using the anticalculus dentifrice had 35.93% less supragingival calculus than the placebo dentifrice subjects, and 52.74% less supragingival calculus than the subjects who continued their regular/customary oral hygiene procedures. After one year, the subjects using the anticalculus dentifrice had 39.76% less supragingival calculus and 18.33% less gingival recession than the subjects using the placebo dentifrice. Also, after one year, the subjects using the anticalculus dentifrice had 57.86% less supragingival calculus and 16.55% less gingival recession than the subjects who continued their customary oral hygiene procedures. All reductions were statistically significant at the 99% level of confidence.