不同形状固位钉对前牙基托抗剪切力的影响

The effect of different retention pin on the shear force of anterior base plate

目的:通过对样本进行抗剪切力的测量,比较不同形状固位钉对前牙区树脂基托的增强效果。方法:将24个大小相同、厚薄均匀的试件随机分为4组,每组6个。其中3组为试件树脂基托内均安插了1枚固位钉的实验组,各组固位钉形状不同,分别为Δ型、V型和I型。另1组试件则为不添加任何加强措施的树脂基托,作为对照组。通过万能力学测试机检测样本的抗剪切力,采用SPSS10.1软件包对数据进行统计学分析。结果:Δ型组、V型组、I型组和对照组的抗剪切力分别为(326.80±64.17)N、(225.07±31.76)N、(182.85±15.18)N和(116.67±4.35)N。I型组和V型组抗剪切力无显著差异(P>0.05),但2组抗剪切力均显著大于对照组(P<0.05);Δ型抗剪切力显著大于其他3组(P<0.05)。结论:Δ形状的固位钉可显著增强前牙树脂基托的抗剪切力,使基托不易折裂。

PURPOSE： The purpose of this study was to compare the effect of enhancement by different shape retention nails on the anterior region resin denture base through shear strength measurements. METHODS： 24 specimens with the same size and thickness were divided into 4 groups by the shape of retention nails. Three experimental groups of the resin denture base specimen were placed a retention nail with different shape, A type, V type and I type. Another group of 6 specimens without nail was used as control. All the samples＇ shear forces were tested by universal mechanical testing machine, and the data was statistically analyzed by SPSS 10.1 software package. RESULTS： The shear forces of A type group, V type group, the I type group and control group, were respectively （326.80~64.17） N, （225.07_＋31.76） N, （182.85 ~ 15.18） N, and （116.67soil 4.35） N. According to the statistical results, the difference of shear forces had no significant difference （P〉0.05） between I type and V type, although the shear forces of these two groups were significantly greater than the control group （P〈0.05）. The shear forces of A type group were significantly greater than the other three groups （P 〈0.05）. CONCLUSIONS： The retention nail of A shape can significantly enhance the anti-shear ability of resin denture base. Supported by Research Fund of Science and Technology Commission of Shanghai Municipality（08DZ2271100）, Shanghai Leading Academic Discipline Project （s30206） ,Foundation of Shanghai Municipal Health Bureau（2010268）,and Medical Engineering Research Foundation of Shanghai Jiao Tong University（YG2011MS23）.