Check out this answer from Consensus:
While dental resins are essential in restorative dentistry, their potential toxicity cannot be overlooked. The release of monomers and additives, their cytotoxic effects, and the systemic implications of substances like BPA highlight the need for more accurate and standardized analytical research. Further studies are necessary to improve the biocompatibility of these materials and ensure patient safety.
Dental resins, commonly used in restorative dentistry, have raised concerns regarding their potential toxicity. These materials, while effective in dental restorations, are not inert and can release various components into the oral environment. This article explores the potential toxic effects of dental resins, focusing on the release of monomers and additives, their cytotoxicity, and the implications for patient health.
Release of Components from Dental Resins
Resin-based dental materials can release components due to incomplete polymerization and degradation over time. Studies have shown that these materials can release monomers such as HEMA, TEGDMA, BisGMA, and UDMA, as well as additives like initiators, inhibitors, and stabilizers1. The release is more significant in organic media compared to water-based media, and the total quantity of released components correlates with the volume of the extraction solution1.
Cytotoxicity of Dental Resin Components
In vitro and in vivo studies have identified the cytotoxicity of various components of dental resins. The short-term release of free monomers during the monomer-polymer conversion and the long-term release due to erosion and degradation can lead to cytotoxic effects2. The mechanisms of cytotoxicity involve glutathione depletion and reactive oxygen species (ROS) production, leading to cell apoptosis2. Additionally, studies have shown that resin monomers can disturb cell viability and cause toxicity in oral eukaryotic cells5.
Comparative Toxicity of Resin Monomers
The cytotoxicity of resin monomers has been compared to that of mercury compounds. Studies have shown that HEMA, TEGDMA, UDMA, and BisGMA have lower toxicity compared to mercury compounds like HgCl2 and MeHgCl3. However, the concentrations of these monomers that might induce necrotic cell death in the human physiological situation are unlikely to be reached solely by eluted substances, indicating that other factors may contribute to tissue inflammation after dental restoration3.
Molecular Toxicology and Systemic Effects
The molecular toxicology of substances released from resin-based dental materials has been extensively studied. These substances can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbances in basic cellular functions4. The release of bisphenol A (BPA) from resin composites, due to insufficient polymerization and degradation, has also been highlighted as a concern. BPA can be hydrolyzed in human saliva and absorbed by the oral/gastrointestinal mucosa, potentially leading to systemic toxicity6.
Autophagy and Therapeutic Targets
Recent studies have explored the role of autophagy in resin monomer-induced cytotoxicity. For instance, TEGDMA exposure has been shown to induce autophagy in human dental mesenchymal cells, which can be prevented by the antioxidant N-acetyl cysteine (NAC)5. This suggests that targeting autophagy could be a potential therapeutic strategy to mitigate the toxicity of dental resins.
Are dental resins toxic?
Anne Young has answered Unlikely
An expert from University College London in Dentistry
BPA is a reactant used in the manufacture of BISGMA resin that is employed in some dental composites. With improvements in purification of BISGMA and removal of this monomer resin from many new composites, toxicity problems arising with BPA are now unlikely.
Silver mercury amalgam fillings have been used safely and effectively for nearly 200 years. They are being phased out for use in children from July 2018 and in adults from 2020 due to the Minamata agreement. This is due to environmental concerns arising with mercury getting into fish rather than filling toxicity.