Influence of Three Types of Abutments on Preload Values Before and After Cyclic Loading with Structural Analysis by Scanning Electron Microscopy
Influence of Three Types of Abutments on Preload Values Before and After Cyclic Loading with Structural Analysis by Scanning Electron Microscopy
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DOI：
10.11607/jomi.2481
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发表时间：
2013-05-01
影响因子：
2
通讯作者：
Arioli Filho, Joao Neudenir
中科院分区：
文献类型：
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作者：
Butignon, Luis Eduardo;Basilio, Mariana de Almeida;Arioli Filho, Joao Neudenir
目的：评价三种类型基台在循环加载前后对螺钉连接预紧力的维持效果，并通过扫描电镜观察各组件在结构上可能出现的微损伤。材料与方法：将45个外六角种植体包埋在环氧树脂中，放置相应的基台，随机分为3个实验组（n = 15）：(1)加工钛（Ti）基台；(2)预加工金（Au）基台；(3)机械氧化锆（ZrO2）基台。根据制造商推荐的扭矩拧紧基台螺钉。首先，进行静态弯曲试验，每组5个试件，以确定循环加载试验中施加的载荷。因此，每组各取10个试件，分别测量加载前后基台螺钉的反向扭矩值（预载荷）。循环加载（0.5 × 10(6)次）；15赫兹)在11和211 N之间，以30度角施加植入物的长轴。组均值比较采用方差分析和Tukey检验（alpha = 0.05）。结果：循环加载前反向扭矩分析各组间差异无统计学意义（P < 0.05）。循环加载后，各预紧力均显著减小。Ti组预负荷下降幅度最小，ZrO2组预负荷下降幅度最大，两者差异有统计学意义（P = 0.010）。金组有中度下降，与其他组比较差异无统计学意义（P < 0.05）。SEM图像显示了循环加载后基台配合面结构的变化。结论：负荷处理显著降低各组预负荷平均值，其中ZrO2组更显著。
Purpose: To evaluate the effectiveness of three types of abutments in the maintenance of screw joint preload before and after cyclic loading as well as to observe possible microdamage in the structure of the components using a scanning electron microscope (SEM). Materials and Methods: Forty-five external-hex implants were embedded in epoxy resin, received their respective abutments, and were randomly divided into three experimental groups (n = 15): (1) machined titanium (Ti) abutments; (2) pre-machined gold (Au) abutments; and (3) machined zirconia (ZrO2) abutments. The abutment screws were tightened according to the manufacturer's recommended torque. Initially, a static bending test was performed using five specimens of each group to determine the load applied in the cyclic loading test. Thus, 10 specimens of each group were used to measure the reverse torque value (preload) of the abutment screw before and after loading. A cyclic loading (0.5 x 10(6) cycles; 15 Hz) between 11 and 211 N was applied at an angle of 30 degrees to the long axis of the implants. The group means were compared using analysis of variance and the Tukey test (alpha = .05). Results : The reverse torque analysis before cyclic loading showed no significant difference among the groups (P > .05). After cyclic loading, all preload means decreased significantly. The lowest decrease in preload was observed in the Ti group, whereas the highest decrease was observed in the ZrO2 group, with a significant difference noted between them (P = .010). The Au group presented an intermediate decrease, with no significant difference compared to the other groups (P > .05). SEM images showed structural changes in the mating surfaces of the abutments after cyclic loading. Conclusion: The load application reduced the preload means significantly in all groups, and more significantly in the ZrO2 group.