Rubber Dam Use and Bisphenol a From Dental Treatment

Objectives: Low dose BPA exposure in childhood may lead to adverse health impacts. Many resin-based dental materials elute BPA making them a potential significant source of exposure. A study in adults reported that use of a rubber dam decreases exposure to BPA from resin-based dental materials. Use of an Isolite may similarly reduce exposure to BPA. We examined the magnitude of dental BPA exposure in children by measuring urinary BPA (uBPA) concentrations before and after dental treatment overall and for those who received dental treatment with a rubber dam, or Isolite or cotton roll/no barrier.
Methods: We conducted a prospective cohort study in 211 children, 4-12 years old, recruited from a university pediatric dental clinic. We enrolled children with no prior resin-based dental treatment. We measured uBPA concentrations twice pre-treatment and 24 hours, 1, 4, and 16 weeks post-treatment. We abstracted treatment data (surfaces treated, barriers used) from the chart. We compared pre- and post-treatment uBPA concentrations using Generalized Estimating Equations.
Results: Participants were 50% female, 48% Caucasian, and 75% publicly insured. Mean (SD) of age was 6.4 (1.9) years. The mean (SD) number of tooth surfaces exposed to BisGMA materials (composites/sealants) was 6.9 (SD 5.5). Overall, uBPA concentrations were 82% higher (95% CI: 40%, 137%) 24 hours post-treatment compared with pre-treatment and returned to pretreatment levels by 4 weeks. Mean uBPA concentrations 24 hours post- versus pre-treatment was significantly higher for those treated with a rubber dam (96%, 95% CI: 42%, 169%) but not Isolite, (60%, 95% CI: -2%, 161%) or cotton roll/no barrier (100%, 95% CI: -17%, 386%). The interaction between treatment and barrier was not statistically significant (p=0.62).
Conclusions: Although it has been hypothesized that rubber dams and Isolite protect against BPA exposure, we found no evidence for such a protective effect in this cohort of children.