The effect of NaF and SMFP toothpastes on three-year caries increments in adolescents

A three-year double blind clinical caries trial was undertaken to compare the anticaries efficacy of three types of active agent, namely sodium fluoride (NaF), sodium monofluorophosphate (SMFP) and the combination of NaF plus sodium trimetaphosphate (TMP), using two fluoride levels (1000 ppm F and 1500 ppm F). The prime objective of the study was to determine whether there was any difference in the anticaries efficacy between NaF and SMFP. The second objective was to assess the effect on caries protection of the incorporation of TMP into a NaF dentifrice formulation. The study was carried out to FDI protocol and involved 4,294 children aged 11-12 years at outset. These participants had been selected from a pool of 6,212 potential subjects on the basis of caries experience and dental eruption pattern. They were stratified by sex, examiner, presence of calculus and caries, and allocated at random to one of the six toothpastes under study. Clinical examinations were carried out at baseline and thereafter annually for 3 years. Bitewing radiographs of a subset of children were taken at baseline and at the end of the study. The outcome measure for the study, DMFS increment, was defined as the increase in caries over three years, taking into account changes occurring on individual tooth surfaces. After three years, clinical-only data for 3,517 children were available for the calculation of caries indices. The mean three-year DMFS increment for subjects using a dentifrice containing NaF alone was 6.4 per cent lower than for those using a dentifrice containing SMFP. The difference between the NaF+TMP users and the SMFP users was 8.1 percent.(ABSTRACT TRUNCATED AT 250 WORDS)