5种复合树脂不同水浴时间的压缩强度体外实验评价

目的　评价5种市场常用的复合树脂固化后经不同水浴时间压缩强度的变化。方法　将5种复合树脂（Nulite F，Filtek Z250，Filtek P60，Beautifil II，Charisma）分别制作24个圆柱体试件并固化，每种复合树脂再分为4组，每组6个样本，其中1组浸泡于37 ℃蒸馏水浴1 h，另外3组分别接受蒸馏水浴1 d、7 d和30 d，测试各组的压缩强度值。测试结果以One-way ANOVA和LSD法统计学检验。结果　水浴1 d后，各品牌复合树脂的压缩强度值均有明显提高。树脂试件经1 h水浴时，Filtek Z250的平均压缩强度最高，Beautifil II其次；1 d和7 d水浴后，Filtek P60 和Filtek Z250的压缩强度最高，Beautifil II居中；30 d水浴后，Filtek Z250的压缩强度最高。结论　Filtek P60和Filtek Z250具有较好的抗压性能，复合树脂充填修复一段时间后压缩强度值才能达到最大。

In vitro evaluation of compressive strength of five composite resins suffering from water storage for different time

Objective To evaluate the variation of compressive strength of five common composite resins for different water bathing time.Methods Five composite resins（Nulite F,Filtek Z250,Filtek P60,Beautifil II,Charisma） were used to make cylindrical specimens（n=24）.Each kind of composite resins was divided into four groups with 6 specimens.One group was stored in distilled water at 37 ℃ for 1 hour,and the others were stored in distilled water at 37 ℃ for 24 h,7 days and 1 month respectively.All of the specimens were tested for ultimate compressive strength.Results were analyzed by One-way ANOVA and LSD test.Results The compressive strength of all brands of composite resins improved significantly after 1d′s water storage.Filtek P60 and Filtek Z250 had the highest compressive strength in 24 hour-and 7 days-water storage groups.Filtek Z250 showed the highest compressive strength in 1 hour-and 30 days-water storage groups.Conclusions Filtek P60 and Filtek Z250 have higher compressive strength.The compressive strength of composite resins would reach to max after set for a period.