Study objectives: Perfluoroalkyl acids (PFAAs) are a class of anthropogenic and persistent compounds that may impact some biological pathways related to oral health. The objective of our study was to estimate the relationship between dental caries prevalence and exposure to four PFAA: perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorohexane sulfonic acid (PFHxS) and perfluorooctane sulfonic acid (PFOS) in a nationally representative sample of US adolescents.
Setting/design: We analysed cross-sectional data from the National Health and Nutrition Examination Survey from 1999 to 2012 for 12-19-year-old US adolescents.
Participants: Of 10 856 adolescents aged 12 to 19 years who had a dental examination, we included 2869 with laboratory measurements for serum PFAA concentrations and complete covariate data in our study.
Primary and secondary outcome measures: Dental caries prevalence was defined as the presence of decay or a restoration on any tooth surface, or the loss of a tooth due to tooth decay. We used multivariable logistic regression to estimate the covariate-adjusted association between serum PFAA concentrations and dental caries prevalence, accounting for the complex National Health and Nutrition Examination Survey design.
Results: Of 2869 adolescents, 59% had one or more dental caries. We observed no associations between the prevalence of dental caries and serum concentrations of PFOA, PFOS or PFHxS. The adjusted odds of caries were 21% (OR 0.79; 95% CI 0.63 to 1.01), 15% (OR 0.85; 95% CI 0.67 to 1.08) and 30% (OR 0.7; 95% CI 0.55 to 0.90) lower among adolescents in the 2nd, 3rd and 4th serum PFNA concentration quartiles compared to adolescents in the first quartile, respectively. The linear trend for this association was not statistically significant.
Conclusion: PFOA, PFOS and PFHxS were not associated with prevalence of dental caries. The prevalence of caries was reduced with increasing serum PFNA concentrations; however, these results should be interpreted cautiously given that we were unable to adjust for several factors related to oral health.