Direct evidence concerning the 'major role' of fluoride dentifrices in the caries decline. A 6-year analytical cohort study.

The role of fluoride (F) dentifrices in caries decline was investigated by assessing the effect of variation in their use on caries scores among teenagers. The material comprised 211 subjects aged about 11 years at base line and 18 years at the last examination. Pairs of posterior bitewing radiographs were assessed by one examiner. Information concerning dental health behavior was collected by questionnaire and about treatment received from dental records. A reversal of the traditional DFS gender difference occurred during teenage years. Multivariate regression analyses showed an inverse relationship between variation in F dentifrice use and current decay (D1S) at age 18 years (P < 0.04) and with caries incidence per year (D1FS) during the whole observation period (P < 0.02). Total explained variance in 6-year deltaD1FS scores was 29.8%, of which variation in toothbrushing behavior contributed 1.8 percentage points. While confirming the multifactorial nature of dental caries, these results also provided quantitative evidence for the role of variation in F dentifrice use in caries incidence and decline.