Srimurugan-Thayanithi Nirosa, Abou-Ayash Samir, Yilmaz Burak, Schimmel Martin, Brägger Urs
Int J Oral Maxillofac Implants. 2023 Jan-Feb;38(1):94-100. doi: 10.11607/jomi.9499.
To evaluate the effect of cooling on the reverse torque values of different abutments in bone-level and tissue-level implants. The null hypothesis was that there would be no difference in reverse torque values of abutment screws when cooled and uncooled implant abutments were compared. Bone-level and tissue-level implants (Straumann, each n = 36) were placed in synthetic bone blocks and subdivided into three groups (each n = 12) based on the abutment type (titanium base, cementable abutment, abutment for screw-retained restorations). All abutment screws were tightened to 35 Ncm torque. In half of the implants, a dry ice rod was applied on the abutments close to the implant-abutment connection for 60 seconds before untightening the abutment screw. The remaining implant-abutment pairs were not cooled. The maximum reverse torque values were recorded using a digital torque meter. The tightening and untightening procedure was repeated three times for each implant including cooling for the test groups, resulting in 18 reverse torque values per group. Two-way analysis of variance (ANOVA) was used to analyze the effect of cooling and abutment type on the measurements. Post hoc tests were used to make group comparisons (α = .05). The values of post hoc tests were corrected for multiple testing using the Bonferroni-Holm method. The null hypothesis was rejected. Cooling and abutment type significantly affected the reverse torque values in bone-level implants ( = .004) but not in tissue-level implants ( = .051). The reverse torque values of bone-level implants significantly decreased after cooling (20.31 ± 2.55 Ncm vs 17.61 ± 2.49 Ncm). Overall mean reverse torque values were significantly higher in bone-level implants compared to tissue-level implants (18.96 ± 2.84 Ncm vs 16.13 ± 3.17 Ncm; < .001). Cooling of the implant abutment led to a significant decrease in reverse torque values in bone-level implants and may therefore be recommended as a pretreatment before the application of procedures to remove a stuck implant part.
为评估冷却对骨水平和软组织水平种植体中不同基台反向扭矩值的影响。无效假设为，比较冷却和未冷却的种植体基台时，基台螺钉的反向扭矩值不会有差异。将骨水平和软组织水平种植体（士卓曼，各n = 36）植入合成骨块中，并根据基台类型（钛基台、可粘结基台、用于螺丝固位修复体的基台）分为三组（每组n = 12）。所有基台螺钉均拧紧至35 Ncm扭矩。在一半的种植体中，在拧松基台螺钉前，将干冰棒靠近种植体 - 基台连接处施加在基台上60秒。其余种植体 - 基台对不进行冷却。使用数字扭矩计记录最大反向扭矩值。对每个种植体重复拧紧和拧松过程三次，测试组包括冷却，每组产生18个反向扭矩值。采用双向方差分析（ANOVA）分析冷却和基台类型对测量结果的影响。使用事后检验进行组间比较（α = .05）。使用Bonferroni - Holm方法对事后检验的值进行多重检验校正。无效假设被拒绝。冷却和基台类型对骨水平种植体的反向扭矩值有显著影响（P = .004），但对软组织水平种植体无显著影响（P = .051）。冷却后，骨水平种植体的反向扭矩值显著降低（20.31 ± 2.55 Ncm对17.61 ± 2.49 Ncm）。与软组织水平种植体相比，骨水平种植体的总体平均反向扭矩值显著更高（18.96 ± 2.84 Ncm对16.13 ± 3.17 Ncm；P < .001）。种植体基台的冷却导致骨水平种植体的反向扭矩值显著降低，因此可能推荐在应用去除卡住的种植体部件的程序之前进行预处理。
