- 期刊
Evaluation of original and non-original abutment screw with reverse torque values after dynamic loading: an in-vitro study
摘要
Objective: This in vitro study aimed to assess how eccentric cyclic loading affects abutments and screws in internal hexagon implant systems from different manufacturers. Materials and methods: The internal hex implant system, Biomet 3i, was tested. The experiments were performed using original screws, replica screws, original abutments, and replica abutments. Nine combinations (three samples from each of three groups) were assessed. The implant body was firmly held in a special jig and the abutment screws were tightened to the manufacturers' recommended torque with a digital torque gauge. A cyclic loading of 400 N was applied at 30 degrees to the implant for 50,000 cycles. The reverse torque value (RTV) of the abutment screw was measured before and after the loading process. The data were analyzed with one-way analysis of variance and post hoc tests, with the significance level set to P < 0.05. Results: The post-loading RTV was significantly higher than the initial pre-loading RTV. The groups with original abutments and replica screws had the highest RTV whether measured before or after loading. Conclusions: This study shows that the screw material has an impact on the RTV. Scanning electron microscopic(SEM) analysis showed that the replica screws were made of a material similar to that of the original screws. The test groups using replica screws demonstrated higher RTV than those using original screws. Therefore, replica screws could be an alternative for clinical use.