Brackett M Goël, Bouillaguet S, Lockwood P E, Rotenberg S, Lewis J B, Messer R L W, Wataha J C
School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1100, USA.
J Biomed Mater Res B Appl Biomater. 2007 May;81(2):397-402. doi: 10.1002/jbm.b.30676.
The biological response to dental restorative polymer composites is mediated by the release of unpolymerized residual monomers. Several new composite formulations claim to reduce unpolymerized residual mass. The current study assessed the cytotoxic responses to several of these new formations and compared them with more traditional formulations. Our hypothesis predicted that if these new polymerization chemistries reduce unpolymerized residual mass, the cytotoxicity of these materials also should be reduced relative to traditional formulations.
Materials (HerculiteXRV, Premise, Filtek Supreme, CeramxDuo, Hermes, and Quixfil) were tested in vitro in direct contact with Balb mouse fibroblasts, initially, then after aging in artificial saliva for 0, 1, 3, 5, or 8 weeks. The toxicity was determined by using the MTT assay to the estimate SDH activity. Knoop hardness of the materials also was measured at 0 and 8 weeks to determine whether surface breakdown of the materials in artificial saliva contributed to cytotoxic responses.
Materials with traditional methacrylate chemistries (Herculite, Premise, Filtek Supreme) were severely (>50%) cytotoxic throughout the 8-week interval, but materials with newer chemistries or filling strategies (Hermes, CeramXDuo, and Quixfil) improved over time of aging in artificial saliva. Hermes showed the least cytotoxicity at 8 weeks, and was statistically equivalent to Teflon negative controls. Hardness of the materials was unaffected by exposure to artificial saliva.
Newer polymerization and filling strategies for dental composites show promise for reducing the release of unpolymerized components and cytotoxicity.
对牙科修复用聚合物复合材料的生物学反应是由未聚合的残留单体的释放介导的。几种新的复合材料配方声称可减少未聚合的残留质量。本研究评估了对其中几种新配方的细胞毒性反应，并将它们与更传统的配方进行比较。我们的假设预测，如果这些新的聚合化学方法减少了未聚合的残留质量，那么相对于传统配方，这些材料的细胞毒性也应该降低。
材料（HerculiteXRV、Premise、Filtek Supreme、CeramxDuo、Hermes和Quixfil）首先在体外与Balb小鼠成纤维细胞直接接触进行测试，然后在人工唾液中老化0、1、3、5或8周后再次测试。使用MTT法测定毒性以估计琥珀酸脱氢酶活性。还在0周和8周时测量材料的努氏硬度，以确定材料在人工唾液中的表面分解是否导致细胞毒性反应。
具有传统甲基丙烯酸酯化学组成的材料（Herculite、Premise、Filtek Supreme）在整个8周期间具有严重的（>50%）细胞毒性，但具有更新化学组成或填充策略的材料（Hermes、CeramxDuo和Quixfil）在人工唾液中老化时细胞毒性随时间改善。Hermes在8周时显示出最小细胞毒性，并且在统计学上与聚四氟乙烯阴性对照相当。材料的硬度不受暴露于人工唾液的影响。
牙科复合材料的新型聚合和填充策略有望减少未聚合成分的释放和细胞毒性。
