DMFS and Fluorosis in 12-Year Old Puerto Ricans

Puerto Rico has no community based fluoridation program. Objective: the purpose of this project was to examine the relationship between DMFS and Dean Index (DI) scores for fluorosis. Methods: DI was used as a proxy for past fluoride exposures at the individual level. Calibrated examiners (4) evaluated a total of 1,443 12-year old Puerto Ricans in 1997. A probabilistic stratified sample of schools (71) were selected from 11 regions. Fluorosis scores of 0.5 were reclassified as 0 scores. Public/private school attendance was used as a surrogate for socioeconomic status (SES) level. The square root of DMFS scores were regressed on DI scores, controlling for gender and SES (SUDAAN, robust variance, exchangeable correlation structure). Linear and non-linear trends were modeled. Results: gender and SES were significant in all models (p<0.003). Fluorosis was not significant for a linear trend (p=0.251). However, as categorical variables, fluorosis scores of 3 (n=33) approached significance (p=0.064). This suggested dichotomizing fluorosis as <3 and >/=3. Severe fluorosis (>/=3) was statistically significant (p=0.009) for higher DMFS levels. This study demonstrated a relationship between DMFS and severe fluorosis in a non-fluoridated community with CFI´s at a public health significance levels of "medium" and less. Conclusions: 1) severe fluorosis may be a risk factor for caries, 2) children at risk for caries may also be at risk for severe fluorosis, 3) fluoride exposure timing may be different for caries protection and fluorosis risk in this population and 4) caries analyses may be improved by adjustment not only of fluoride exposures, but also for the presence of levels 3 and 4 fluorosis.