Department of Prosthodontics and Restorative Dentistry, School of Dentistry, Complutense University of Madrid, 28040 Madrid, Spain.
Department of Surgery, Faculty of Medicine, University of Salamanca, 37007 Salamanca, Spain.
Int J Environ Res Public Health. 2020 Dec 27;18(1):125. doi: 10.3390/ijerph18010125.
This study aimed to analyze a novel technique to make screws with greater untightening resistance and to solve screw loosening in implant-supported single crowns. Thirty grade IV titanium straight abutments were screwed onto 30 external hex implants using grade IV titanium screws (30 Ncm). They were exposed to cyclic loading (300,000 cycles, 200 N). Samples were divided into 4 groups (15 samples per group): new screws (SCREW group) (control), reused screws (rSCREW group), new screws wrapped with polytetrafluoroethylene (PTFE) tape (PTFE group), and reused screws wrapped with PTFE tape (rPTFE group). Reverse torque values (RTVs) were recorded with a digitally calibrated implant motor. Mean RTVs observed were 14.46 N (±1.10 N) for the control group, 14.42 N (±1.22 N) for the rSCREW group, 19.97 N (±1.16 N) for the PTFE group, and 19.13 N (±2.38 N) for the rPTFE group. Statistically significant differences were found between RTVs of both groups employing screws without PTFE tape (SCREW and rSCREW groups) compared with those using screws wrapped with PTFE tape (PTFE and rPTFE) ( < 0.001). These results suggest that wrapping the implant-abutment screw with PTFE tape may effectively lower the risk of loosening and even constitute a solution when this complication occurs in implant single crowns.
本研究旨在分析一种新的技术,以提高螺丝的防松动能力,并解决种植体支持的单冠中螺丝松动的问题。将 30 个四级钛直基台用四级钛螺丝(30 Ncm)拧入 30 个外六角种植体上。它们暴露于循环加载(300,000 次循环,200 N)下。样本分为 4 组(每组 15 个样本):新螺丝(SCREW 组)(对照组)、重复使用的螺丝(rSCREW 组)、包裹聚四氟乙烯(PTFE)带的新螺丝(PTFE 组)和包裹 PTFE 带的重复使用的螺丝(rPTFE 组)。使用数字校准的种植体电动机记录反向扭矩值(RTV)。对照组的平均 RTV 为 14.46 N(±1.10 N),rSCREW 组为 14.42 N(±1.22 N),PTFE 组为 19.97 N(±1.16 N),rPTFE 组为 19.13 N(±2.38 N)。发现未使用 PTFE 带的螺丝(SCREW 和 rSCREW 组)与使用 PTFE 带包裹的螺丝(PTFE 和 rPTFE 组)之间的 RTV 存在统计学显著差异(<0.001)。这些结果表明,用 PTFE 带包裹种植体-基台螺丝可能有效地降低松动的风险,甚至在种植体单冠中出现这种并发症时构成一种解决方案。