I would like to start this post with a little philosophical waxing. My goal is to stay healthy enough that I won’t need any man-made body parts. But if I shatter my femur and need a titanium rod placed in it, I am all good with that. Not to mention being put under general anesthesia with whatever chemical they feel is best. In short, when body parts fail, western medicine (and dentistry) is king. I would rather be concerned with the (hopefully) minor toxicities of medical materials then the major problem of missing a leg.

Onto the post…

By now, just about everyone has heard about the hormone-mimicking properties of many plastics, with BPA getting most of the attention. Some dental composites can contain BPA, or derivatives, which can be a cause for concern. Unfortunately, the world is full of plastic chemicals, and every living thing on earth has a measurable tissue level of BPA and we don’t really know if the amount of BPA released from some of the dental composite out there is enough to raise one’s exposure above the general background level.

In the IAOMT ‘s statement on BPA (I am a member), they did 2 studies regarding BPA and estrogen mimicing materials. In 2008, they found that BPA was “in the low parts-per-billion range after 24 hours, on the order of one one-thousandth of the known average daily exposure for adults in the industrialized world”. In 2011, the IAOMT tested to see if there was any demonstration of estrogen activity from dental composites under normal conditions. They looked for estrogen activity from any chemical in dental composite fillings. No estrogenic activity was found. In both cases the known exposure was far below the known toxic dose.

BPA is not the only potentially toxic monomer in composite resins; others may be toxic [1]. In particular, the structure of TEGDMA and HEMA can be degraded by salivary esterases and result in liposoluble metabolites that could accumulate in fatty tissues [2]. Even UDMA, deemed less risky, may present some cytotoxicity beyond a certain concentration [3]. These free monomers are mostly present on the surface of the material, where the exposure to oxygen inhibits polymerization. Removal of the inhibition layer and eliminated more than 90% of the residual monomers. Using a dry or wet cotton roll or even using water/air spray also enables their withdrawal up to 70%.

Since there is no minimum safe dose of mercury, the levels found in one’s blood after amalgam fillings are placed are a huge concern, and you should never have amalgams placed. The choice between silver versus composite fillings is a no-brainer. Always choose the mercury free option! If you need an old silver filling replaced, make sure you request a BPA free composite filling, and by all means, MAKE SURE THE SAFE AMALGAM REMOVAL PROTOCOL IS USED!!! Read my article on the SAFE technique of amalgam removal HERE.

Today, there are several BPA free alternatives, which I use in my practice. Given the option, I would recommend choosing a dentist that uses BPA free alternatives.

If you already have white fillings, most of the chemicals leach out within the first few days (if the dentist polished the new fillings initially, 90% of these monomers were removed at the time of placement). For that reason, I do not recommend you getting rid of them any time soon. If you have any concerns, your dentist can use a similar technique to the safe amalgam removal protocol to remove the old composites.

Another way to minimize exposure to BPA and related chemicals is to have a porcelain filling placed. I do these in my practice. They are done using a scanner and a machine but are much more expensive. They are placed with adhesives similar to composite fillings, but since they are under the fillings, there is a much smaller risk to exposure.

In conclusion, even if your dentist uses standard composite filling material, placement or removal of these fillings will result in a temporary rise in detectible chemicals FAR below the threshold of toxicity, whereas placement or removal of amalgam dental fillings which contain mercury WILL case a detectible toxic level of mercury. The choice is clear, choose composite over amalgam. Insist on it!

Footnotes:

1. Minimizing patients' exposure to uncured components in a dental sealant.

   Rueggeberg FA, Dlugokinski M, Ergle JW

   J Am Dent Assoc. 1999 Dec; 130(12):1751-7.

2. In vitro stability of methylmethacrylic acid, TEGDMA and HEMA exposed to esterases.

   Seiss M, Track N, Hickel R, Reichl FX

   Dent Mater. 2009 Aug; 25(8):1044-9.

3. Review Cytotoxicity of components of resins and other dental restorative materials.

   Wataha JC, Hanks CT, Strawn SE, Fat JC

   J Oral Rehabil. 1994 Jul; 21(4):453-62.