Increased release of Bisphenol- A from resin composites tied to toxicity: Study

A group of researchers from Portugal conducted a study to perform an integrative review on the release of bisphenol A (BPA) from resin-matrix composites and potential toxic effects.

A bibliographic search was performed by the researchers on the PubMed platform using the following keywords: "Bisphenol A" OR "BPA" AND "resin composite" OR "composite resin" AND "toxicity" OR "cytotoxicity" OR "release". Inclusion criteria involved in vitro and in vivo studies on the release and toxicity of BPA.

The results of the study are as follows:

· The release of BPA from resin-matrix composites due to insufficient polymerization and/or degradation of the polymeric matrix.

· BPA is part of the organic matrix of resin-matrix composites and may be hydrolysed in human saliva, although studies report that low doses might not be detected by traditional chemical analysis.

· Studies exposing zebrafish embryos to different concentrations of Bis-GMA, showed 55% mortality at 10 μM Bis-GMA while 30% mortality was recorded at 1 μM Bis-GMA.

· In patients, a BPA concentration of around 2.09 × 10−2 μg/ml was found in the saliva after placement of lingual orthodontic retainers with resin-matrix composites.

· Also, the BPA molecule can be swallowed and absorbed by the oral/gastrointestinal mucosa, which might result in systemic toxicity.

· The degradation of resin-matrix composites and release of BPA in an oral environment is dependent on the organic matrix content and on the polymerization method.

Thus, the researchers concluded that increased release of BPA can lead to the absorption into oral and gastrointestinal mucosa with high risks of local and systemic toxicity.

Reference:

An integrative review on the toxicity of Bisphenol A (BPA) released from resin composites used in dentistry by Rocha L et. al published in the Journal of Biomedical Materials Research: Part B.

https://doi.org/10.1002/jbm.b.34843