Abstract：
Dental implants are artificial dental roots anchoring prosthetic restorations to replace natural teeth. Dental implant systems may have different tapered conical connections. Our research focused on the mechanical examination of implant-superstructure connections. Thirty-five samples with 5 different cone angles (24°, 35°, 55°, 75°, and 90°) were tested for static and dynamic loads, carried out by a mechanical fatigue testing machine. Fixing screws were fixed with a torque of 35 Ncm before measurements. For static loading, samples were loaded with a force of 500 N in 20 s. For dynamic loading, the samples were loaded for 15,000 cycles with a force of 250 ± 150 N. In both cases, the compression resulting from load and reverse torque was examined. At the highest compression load of the static tests, a significant difference (p = 0.021) was found for each cone angle group. Following dynamic loading, significant differences (p < 0.001) for the reverse torques of the fixing screw were also shown. Static and dynamic results showed a similar trend: under the same loading conditions, changing the cone angle-which determines the relationship between the implant and the abutment-had led to significant differences in the loosening of the fixing screw. In conclusion, the greater the angle of the implant-superstructure connection, the smaller the screw loosening due to loading, which may have considerable effects on the long-term, safe operation of the dental prosthesis.
摘要：
牙种植体是人工牙根锚固修复体，以替代天然牙齿。牙科植入物系统可以具有不同的锥形连接。我们的研究重点是植入物-上层建筑连接的机械检查。35个样品，具有5个不同的锥角（24°，35°,55°,75°,和90°)进行了静态和动态载荷测试，由机械疲劳试验机进行。在测量前用35Ncm的扭矩固定固定螺钉。对于静态加载，样品在20秒内加载500N的力。对于动态加载，样品以250±150N的力加载15,000个循环。在这两种情况下，由负载和反向扭矩产生的压缩进行了检查。在静态测试的最高压缩载荷下，每个锥角组有显著差异(p=0.021).动态加载后，还显示了固定螺钉的反向扭矩的显着差异（p<0.001）。静态和动态结果呈现相似的趋势:在相同的加载条件下,改变确定种植体和基台之间关系的锥角导致固定螺钉松动的显着差异。总之,植入物-上层建筑连接的角度越大，由于负载而导致的螺钉松动越小，这可能会对长期产生相当大的影响，假牙的安全操作。
