Bisphenol-A (BPA) and dental sealants

This is a tough one.  Right now I can tell you I have no easy answer for anyone out there worrying about the potential health risks of dental sealants and composite filling materials due to Bisphenol-A (BPA) exposure.  I would highly recommend reading an article from 2010 reviewing this topic in Pediatrics (available free online http://pediatrics.aappublications.org/content/early/2010/09/06/peds.2009-2693).  Even if you have no medical background, this article summarizes the findings thus far in easy to understand terms (just ignore the chemical structures if you prefer).

Having discussed some of the evidence supporting my concerns surrounding BPA in another post, I will focus on dental sealants and filling materials in this post.  Because the greatest potential risk for exposure to BPA is in infants, small children and fetuses, the idea of using a plastic that can leach BPA for an elective procedure seems unsettling to many.  Dental resins (such as bis-DMA and bis-GMA) are primarily composed of BPA derivatives, and hydrolyzed by salivary enzymes into BPA.  Studies thus far have only detected spikes of BPA in patient saliva (not blood) immediately (<3 hrs) after a dental procedure.  The studies have shown conflicting patterns, possibly due to differences in assays (testing methods) used.  Most studies have shown that bis-GMA does not hydrolyze into BPA, but bis-DMA does.  It is important to ask your dentist about the specific components of the dental sealant or composite filling material–though some sealants have a combination of ingredients such as BPA ethoxylate dimethacrylate (bis-EMA)  and other urethane-modified bis-GMA, that may have some estrogenic activity but have not been investigated.  Table 1 in the Pediatrics article summarizes sealant components for 90% of the US Market.

Since there is so much uncertainty regarding this topic, it is best to proceed with common sense and use your best judgment.  Ask yourself these questions:  What are the risks for development of dental caries (be realistic)?  If you or your child will need dental repair of cavities, what will be the exposure to BPA at that point? (likely greater than with sealants)  Also consider that since >93% of the US population has measurable urinary BPA (presumably due to food packaging, other daily exposures), how bad is a one time spike in salivary BPA relative to a longer term exposure?  It is believed that BPA has a short half-life and is quickly removed from the body, though the metabolism of BPA is still under investigation.  Precautionary measures can reduce dental exposure to BPA:

1) Choose a bis-GMA sealant if possible–see Table 1 from Pediatrics article.  Keep in mind that there is still a great deal of uncertainty regarding other monomers used in sealants and fillings.

2) Avoid resin placement if pregnant or nursing (if necessary, use precautions to contain saliva that may contain BPA, see below)

3) Gargle water for 30 seconds after resin placement (other measures to reduce exposure to BPA:  rub sealant surface after application with cotton ball & pumice, rinse with an air-water syringe, use a rubber dam during application)

Most dentists are familiar with this topic and should be able to answer the questions you may have about sealants/fillings and exposure to BPA.

BOTTOM LINE:  My children have dental sealants as do I.  I’m just crossing my fingers…

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