Naval Postgraduate Dental School - Prosthodontics, Bethesda, MD.
Uniformed Services University of the Health Sciences, Bethesda, MD.
J Prosthodont. 2019 Dec;28(9):969-972. doi: 10.1111/jopr.13111. Epub 2019 Oct 11.
To compare the reverse torque values (RTVs) of abutment screws tightened from three different angles.
Implant abutment screws (n = 48), abutments (3), and regular platform implant analogs (3) were divided into three angulation groups (n = 16/group). Custom guides of 0°, 10°, and 20° were fabricated to verify driver angulation. The implant components for each group were assembled and all screws torqued to 35 Ncm using a universal screwdriver in a manual torque wrench at the appropriate angle. Torque was reapplied 10 minutes after initial torque. A digital gauge was then used to measure reverse torque at a position parallel (0°) to the implant analog. RTVs were recorded and compared using one-way ANOVA and Tukey HSD post-hoc comparisons (α = 0.05).
All mean RTVs fell below the targeted torque value of 35Ncm, with some values in each angulation group 10% below of the target value. Mean RTVs in descending order from targeted torque value were: 10° group = 32.07 ± 0.97 Ncm, 0° group = 31.16 ± 1.12 Ncm, and 20° group = 30.08 ± 0.88 Ncm. One-way ANOVA revealed significant differences between angulation groups (F = 15.954, p < 0.001). Tukey HSD post hoc comparisons revealed that the mean RTVs of the three angulation groups were significantly different from each other (0° vs. 10°: p = 0.033; 0° vs. 20°: p = 0.011; 10° vs. 20°: p < 0.001).
All RTVs did not reach the targeted torque value of 35 Ncm. Mean screw RTVs were significantly influenced by screwdriver insertion angulation.
比较从三个不同角度拧紧基台螺丝的反向扭矩值（RTV）。
将种植体基台螺丝（n=48）、基台（3 个）和常规平台种植体模拟体（3 个）分为三组不同的角度（n=16/组）。制作 0°、10°和 20°的定制引导器以验证螺丝刀的角度。将每组的种植体组件组装好，然后在适当角度的手动扭矩扳手中使用通用螺丝刀将所有螺丝拧紧至 35 Ncm。初始扭矩 10 分钟后再次施加扭矩。然后使用数字卡尺在与种植体模拟体平行（0°）的位置测量反向扭矩。记录并比较 RTV 值，使用单因素方差分析和 Tukey HSD 事后比较（α=0.05）。
所有平均 RTV 值均低于 35 Ncm 的目标扭矩值，每个角度组的一些值比目标值低 10%。按目标扭矩值降序排列的平均 RTV 值分别为：10°组=32.07±0.97 Ncm、0°组=31.16±1.12 Ncm 和 20°组=30.08±0.88 Ncm。单因素方差分析显示角度组之间存在显著差异（F=15.954，p<0.001）。Tukey HSD 事后比较显示，三组角度的平均 RTV 值彼此之间有显著差异（0°与 10°：p=0.033；0°与 20°：p=0.011；10°与 20°：p<0.001）。
所有 RTV 值均未达到 35 Ncm 的目标扭矩值。螺丝的平均 RTV 值受螺丝刀插入角度的显著影响。
