不同粘结剂与桩核材料微渗漏发生的实验研究

目的：评价不同核材料修复后的牙齿经铸造金属全冠修复后边缘微渗漏的情况。方法：将90个大小相似的完好前磨牙,随机分为9个实验组。对离体牙进行铸造金属全冠及固定尺寸的Ⅱ类洞牙体预备后,分别用3种不同的核材料（树脂、银汞合金、铸造合金）充填窝洞。常规方法铸造镍铬合金全冠,用3种不同的粘结材料（聚羧酸锌、玻璃离子、树脂C＆B）进行粘固。温度循环、染色、包埋后,标本片切,镜下观察冠边缘及核下微漏情况。结果：银汞核与树脂核下微漏小于铸造核（P〈0.05）,树脂粘结剂抗微漏性能优于聚羧酸锌水门汀和玻璃离子粘结剂（P〈0.05）。结论：树脂粘接剂抗微漏性能优于玻璃离子与聚羧酸锌粘结剂。树脂核在预先对粘结面处理后,其抗微漏性能与银汞核近似,优于铸造合金核。

Contrast study of the microleakage of several clinical and frequently used cements and dowel materials

Objective：The aims of this investigation were to evaluate microleakage patterns of of complete cast-metal crowns cemented onto teeth that were rebuilt with different core materials.Method：ninety extracted molar teeth were cleaned and mounted.Nine restorative groups were formed.Tooth preparations for complete veneer cast crownswere completed.A classⅡcavity preparationwith fixed dimensionwasmade in each tooth.Three different core materials（composite resin,amalgam,cast-gold）were filled in them.Artificial crowns were cast and cemented onto teeth by using three different cements（composite resin super bond CB,glass ionomer CX,zinc polycarboxylate）.The specimens were thermocycled and dyed.They were then embedded in epoxy resin and sectioned.The extent of microleakage was evaluated and scored.Result：The least core microleakage was recorded for amalgam and composite resin（P 0.05）.The microleakage of composite resin is less than those of glass ionomer and Zinc polycarboxylate（P 0.05）.Conclusion：The findings indicated that the microleakage of composite resin is less than those of glass ionomer and zinc polycarboxylate,and the microleakage of amalgam and composite resin is less than that of cast-gold core materials.