We all know that Bisphenol-A (BPA) is considered a hormone disruptor and is toxic to nerves, and we all have seen labels on baby bottles that state “BPA Free.” Yay!!! But, did you know that BPA has what I call a “family?” BPA belongs to a family of monomers also known as BPA derivatives. Yes, BPA has relatives that are commonly used in dental materials, such as:

Bis-GMA (glycidyl dimethacrylate), which is a product of BPA + glycidyl methacrylate. Some composite resins with Bis-GMA contain BPA it as an impurity, and some studies have found that BPA can leach as a degradation product. Bis-GMA has been found to decrease sperm count in male mice, as well as have toxic reproductive effects in female mice. It has also been found to cause DNA strand breakage.

Bis-DMA (bisphenol A dimethacrylate), the ester linkage of which undergoes hydrolysis in saliva which results in the degradation of BisDMA into BPA.

UDMA (urethane dimethacrylate), which has a toxic effect on macrophages in some studies
TEGDMA (triethylene glycol dimethacrylate) in combination with Bis-GMA had a pro inflammatory effect on neutrophils. It increased Interleukin 8 production, AND has been found to stimulate the growth of S. Mutans and S. Salivarius (bacteria which are thought to contribute to cavity production), which explains why cavities can develop underneath composite fillings. TEGDMA also induces glutathione depletion and causes cell toxicity. It has been found to have reproductive toxic effects in female mice.

The toxicity of the above monomers to cells increases as follows: HEMA < TEGDMA < UDMA < BisGMA (most toxic to cells)

In my office, we often use Admira Fusion ceramic-based restorative material, which does not include any of the above monomers. The matrix and fillers are based on silicon oxide (think glass and ceramic). The material is tooth colored and handles the same way as conventional composites, but is entirely BPA free.