The effect of an anticalculus dentifrice on calculus formation and gingival recession in Thai children and teenagers: one-year study.  Study #1.  An anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% of a copolymer. 
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 1) a placebo dentifrice containing 0.243% sodium fluoride in a silica base, 2) an anticalculus dentifrice containing 3.3% soluble pyrophosphate and 1.0% Gantrez copolymer--in a 0.243% sodium fluoride/silica base, or 3) continuation of customary oral hygiene procedures.  After one year, the subjects using the anticalculus dentifrice had 37.01% less supragingival calculus and 25.09% less gingival recession than the subjects using the placebo dentifrice.  Additionally, after one year, the subjects using the anticalculus dentifrice had 34.86% less supragingival calculus and 29.95% less gingival recession than the subjects who continued their customary oral hygiene procedures.  All reductions were statistically significant at the 95% or greater level of confidence.