间隙剂层数对镍铬合金基底冠内部适合性和固位力的影响

The Influence of Internal Adaptation and Retention of Ni-Cr Based Crown with Different Coating Layers of Diespacer

目的:比较涂布不同层数间隙剂对镍铬合金基底冠内部适合性和固位力的影响。方法:选取30颗无龋第一前磨牙,牙体预备后制备代型,按照在代型上涂布TP间隙剂层数(1层、2层及3层)的不同分为3组(第1组、第2组及第3组)制备镍铬合金基底冠,印模技术法测量冠内部适合性。然后用玻璃离子水门汀粘冠制成试件,于人工唾液浸泡1个月,循环加载10000次后测试试件的冠固位力。结果:第1组和第2组获得的基底冠内部适合性均优于第3组(P<0.01),第1组和第2组相比差异无统计学意义(P>0.05);第2组试件获得的冠固位力大于第1组和第3组(P<0.05或P<0.01)。结论:制作镍铬合金基底冠时,涂布2层间隙剂获得的临床效果最佳。

Objective：To compare the internal adaptation and retention of Ni-Cr based crown with different coating layers of diespacer.Methods：A total of 30 intact human first premolars extracted freshly were collected.After tooth preparation,30 dies were made and randomly divided into 3 groups according to different coating layers of diespacer.Ni-Cr alloy was selected to fabricate based crowns which were cemented to teeth with polyether impression material to measure the internal adaptation.Then the samples were made of the crowns and teeth bonded with Fuji glass ionomer.After immersed in artificial saliva for 1 month and subjected to 10 000 cyclic mechanical loading,the samples were sent to measure the force at which retention failed.Results：No significant difference was found in internal adaptation between groups coated with one and two layers of diespacer on the die（P 0.05）,in while both of them had significant difference with the one coated with three layers（P 0.01）.The group coated with two layers of diespacer on the die had bigger retention forces than that of the other groups（P 0.05 or P 0.01）.Conclusion：When Ni-Cr alloy was selected to manufacture based crown,the die coated with two layers of diespacer showed the best clinical results.