Induction and reduction of DNA toxicity caused by intermediates from dental restorative ma-terials

单体和单体被用作牙齿修复材料。未转化的化合物可以从牙科复合材料中释放出来，并可以进入人体。甲基丙烯酸酯的吸收、分布和排泄已经在动物实验中得到阐明。在这些甲基丙烯酸酯的代谢中检测到中间产物2,3-环氧甲基丙烯酸酯（2,3- ema）和环氧-羟乙基甲基丙烯酸酯（环氧- hema）。环氧化合物被认为是致突变和致癌的化合物。在进一步的研究中，可以证明2,3- ema等化合物实际上可以诱导人类细胞的诱变作用和小鼠干细胞的胚胎毒性。由于环氧化物及其连续反应的潜在反应性，本研究应在人牙龈成纤维细胞和人肝细胞中研究2.3-EMA和环氧- hema对DNA毒性的诱导及其修复机制。在进一步的实验中，应研究抗氧化剂对降低dna毒性的影响。在这些数据的基础上，可以估计人类细胞中释放/代谢的牙科材料的DNA毒性风险特征。

Comonomers and monomers are used as dental restorative materials. Unconverted compounds can be released from dental composites and can enter the body in humans. The uptake, distribution, and excretion of methacrylates have been elucidated in animal stud-ies. In the metabolism of these methacrylates the intermediates 2,3-epoxymethacrylate (2,3-EMA) and epoxy-hydroxyethylmethacrylate (Epoxy-HEMA) were detected. Epoxy-compounds are regarded as mutagenic and carcinogenic compounds. In further studies it could be demonstrated that 2,3-EMA and other compounds could actually induce mutagenic effects in human cells and embryotoxicity in mouse stem cells.Due to the potential reactivity of epoxides and their consecutive reactions, in this study the induction of DNA toxicity by 2.3-EMA and Epoxy-HEMA and repair mechanisms should be examined in human gingival fibroblasts and in human liver cells. In further experiments the influence of antioxidants to reduce DNA-toxicity should be investigated. On the basis of these data, the risk characterization on the DNA toxicity can be estimated for released/metabolized dental materials in human cells.