Fluoridated Public Water Effects on Caries Prevalence in Nevada

Purpose: Although dental caries is largely preventable, it remains the most common chronic disease of adolescents 12 to 19 years old (59%). Reports show differences in dental caries between communities that are and are not fluoridated. The purpose of this study is to asses effects of fluoride in the municipal water supply on caries severity in Nevada adolescents.

Methods: A state-wide surveillance program conducted oral health screenings from 2001-2008. Trained/calibrated licensed dental examiners documented oral health indices of middle/high school students. The 2007-2008 academic year database (N=7410) was used to compare differences in severity between adolescents living in Clark county (N=3312) where fluoridated water has been available since 2000 to those living in Nevada counties (N=4098) where added fluoride is not available in the water supply. Severity was measured using the decayed, missing, and filled permanent teeth (DMFT) index. T-tests were used to compare differences between gender and ethnicity.

Results: There were significant differences in DMFT indices between adolescents living in Clark county (M=2.29) compared to non-fluoridated counties (M=3.57) (t=9.155;p=0.003). There were mean differences by gender (t=9.759,p=0.002) (Clark County: Girls 2.29; Boys=2.47 vs. Outside Clark County: Girls=3.57; Boys=3.22) and Ethnicity (t=6.790, p=.001) (Clark County: non-Hispanics=2.23; Hispanics=2.66 vs. Outside Clark County: non-Hispanics=3.08; Hispanics=3.82).

Conclusions: Significant differences were found between adolescents living within Clark County compared to those outside Clark County. However, there were no significant differences by gender and ethnicity within geographic groups. This study supports the hypothesis that fluoridation of the water supply provides valuable dental benefits to all.