Department of Oral Biology, The Maurice and Gabriela Goldschleger School of Dental Medicine, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.
Department of Oral Rehabilitation, the Maurice and Gabriela Goldschleger School of Dental Medicine, Tel Aviv University, Tel Aviv, Israel.
Clin Implant Dent Relat Res. 2024 Apr;26(2):289-298. doi: 10.1111/cid.13271. Epub 2023 Sep 7.
This in vitro study aims to biomechanically evaluate the influence of medium contamination for example, saliva, blood, chlorhexidine (liquid and gel), and fluoride mouthwash on the biomechanical behavior of implant abutments' screws under static and dynamic loading.
Forty five Ti6Al4V commercial dental implants and abutments were tested in this study. Two main mechanical tests were carried out in the selected media. The first, static, aimed to evaluate the torque loss after the first tightening. The second, dynamic, involved a random cyclic load range between 0 and 200 N to evaluate torque loss due to mastication. In addition, metallographic longitudinal and cross-sections of the abutment-implant apparatus were examined to evaluate the abutment screw-abutment-implant interface.
The static torque test showed that irrespective of the media, no statistical difference in static torque loss was found prior to dynamic loading. For the dynamic tests, torque-angle evolution analysis during tightening to 30 Ncm and after the spectrum loading, showed the same global mechanical behavior for all media, but the statistical analysis indicated a difference between the groups in reverse torque values (RTV) and in the torque loss due to dynamic loading. The medium groups CHX, CHX-gel, and Fluoride mouthwash, showed a meaningful torque loss due to loading, but the medium groups, control (no medium), blood and saliva showed an opposite trend and required a higher torque to open the abutment screws. The microstructural analysis revealed clear signs of cold-welding/galling, post-dynamic loading in these latter groups.
The presence of lubrication/contamination media (CHX mouthwash/CHX-gel/Fluoride mouthwash) reduces the preload generated due to tightening but prevents damage due to galling. The observed reduction of RTV clearly emphasizes the need for frequent abutment screw retightening for implant-supported prosthetic long-term stability.
本体外研究旨在从生物力学角度评估介质污染（例如唾液、血液、洗必泰（液体和凝胶）和含氟漱口水）对静态和动态负载下种植体基台螺钉生物力学行为的影响。
本研究共测试了 45 个 Ti6Al4V 商用牙科种植体和基台。在选定的介质中进行了两项主要的机械测试。第一项为静态测试，旨在评估首次拧紧后的扭矩损失。第二项为动态测试，涉及 0 至 200N 之间的随机循环负载范围，以评估咀嚼引起的扭矩损失。此外，还对基台-种植体装置的金相纵向和横截面进行了检查，以评估基台螺钉-基台-种植体界面。
静态扭矩试验表明，无论介质如何，在动态加载之前，静态扭矩损失均无统计学差异。对于动态测试，在拧紧至 30Ncm 并进行频谱加载期间，扭矩-角度演化分析显示所有介质均具有相同的整体机械行为，但统计分析表明，反向扭矩值（RTV）和动态加载引起的扭矩损失在各组之间存在差异。CHX、CHX 凝胶和含氟漱口水组的加载扭矩损失有显著意义，但对照组（无介质）、血液和唾液组的趋势相反，需要更高的扭矩才能打开基台螺钉。微观结构分析显示，在后一组中，动态加载后出现了明显的冷焊/胶合迹象。
润滑/污染介质（洗必泰漱口水/CHX 凝胶/含氟漱口水）的存在会减少拧紧产生的预紧力，但可防止胶合引起的损坏。观察到的 RTV 降低清楚地强调了需要经常重新拧紧种植体支持的修复体长期稳定性所需的基台螺钉。
