Methacrylates in polymer-resin based dental materials: Assessment of exposure and biological effects

Materials used in dentistry are largely polymer-resin based dental materials (PRMs). PRMs contain methacrylates and organic additives that may cause adverse effects in exposed patients and dental personnel. The purpose of this thesis was to study biological effects of one of the most commonly used methacrylate in PRMs, and to investigate how patients and dental health personnel may be exposed to constituents in PRMs. In paper I, methods and terminology used in cell culture studies on PRM constituents’ toxicity were charted by systematic searches in several search engines. It was found that non-standardized nomenclature and methods are commonly used. In paper II, biological effects of triethylene glycol dimethacrylate (TEGDMA) were charted on the proteomic level in the human THP-1 monocyte cell line. It was shown that TEGDMA induces time- and dose-dependent effects on cells, even at doses previously reported as non-toxic (as shown in Paper I). In paper III, the organic composition of, and eluates from, resin-modified pulp capping materials were examined. It was found that patients may be exposed to a range of organic substances, including methacrylates, if these materials are used for direct capping. In paper IV, release of particle-associated and gaseous organic substances in PRMs during restorative procedures were examined in a simulated, clinical environment. The results of this study reinforced the notion that occupational exposure to particle-associated organic substances in PRMs may occur. However, it was also shown that this exposure was below the limit of detection during clinical circumstances. In conclusion, this thesis add novel knowledge, and strengthen the current understanding, of how patients and dental personnel may be exposed to organic substances in PRMs. It also reinforce the notion that methacrylates are reactive compounds that can induce several biological effects in exposed cells.