Paepoemsin T, Reichart P A, Chaijareenont P, Strietzel F P, Khongkhunthian P
Center of Excellence for Dental Implantology, Faculty of Dentistry, Chiang Mai University, Chiang Mai, Thailand.
Department of Oral Medicine, Dental Radiology and Oral Surgery, Center for Dental, Oral and Maxillary Medicine, Charite - University of Medicine, Berlin, Germany.
Oral Implantol (Rome). 2016 Nov 16;9(4):213-221. doi: 10.11138/orl/2016.9.4.213. eCollection 2016 Oct-Dec.
The aim of this study was to evaluate the removal torque of three different abutment screws and pull out strength of implant-abutment connection for single implant restorations after mechanical cyclic loading.
The study was performed in accordance with ISO 14801:2007. Three implant groups (n=15) were used: group A, PW Plus® with flat head screw; group B, PW Plus® with tapered screw; and group C, Conelog® with flat head screw. All groups had the same implant-abutment connection feature: cone with mandatory index. All screws were tightened with manufacturer's recommended torque. Ten specimens in each group underwent cyclic loading (1×106 cycles, 10 Hz, and 250 N). Then, all specimens were un-tightened, measured for the removal torque, and underwent a tensile test. The force that dislodged abutment from implant fixture was recorded. The data were analysed using independent sample t-test, ANOVA and Tukey HSD test.
Before cyclic loading, removal torque in groups A, B and C were significantly different (B> A> C, P<.05). After cyclic loading, removal torque in all groups decreased significantly (P<.05). Group C revealed significantly less removal torque than groups A and B (P<.005). Tensile force in all groups significantly increased after cyclic loading (P<.05), group A had significantly less tensile force than groups B and C (P<.005).
Removal torque reduced significantly after cyclic loading. Before cyclic loading, tapered screws maintained more preload than did flat head screws. After cyclic loading, tapered and flat head screws maintained even amounts of preload. The tensile force that dislodged abutment from implant fixture increased immensely after cyclic loading.
本研究旨在评估三种不同基台螺丝的拆卸扭矩以及在机械循环加载后单颗种植体修复体的种植体-基台连接的拔出强度。
本研究按照ISO 14801:2007进行。使用了三组种植体（n = 15）：A组，使用平头螺丝的PW Plus®；B组，使用锥形螺丝的PW Plus®；C组，使用平头螺丝的Conelog®。所有组的种植体-基台连接特征相同：带强制索引的锥形。所有螺丝均按照制造商推荐的扭矩拧紧。每组中的十个标本进行循环加载（1×10⁶次循环，10 Hz，250 N）。然后，松开所有标本，测量拆卸扭矩，并进行拉伸试验。记录将基台从种植体固定装置上取下的力。使用独立样本t检验、方差分析和Tukey HSD检验对数据进行分析。
在循环加载之前，A组、B组和C组的拆卸扭矩有显著差异（B > A > C，P <.05）。循环加载后，所有组的拆卸扭矩均显著降低（P <.05）。C组的拆卸扭矩明显低于A组和B组（P <.005）。循环加载后，所有组的拉伸力均显著增加（P <.05），A组的拉伸力明显低于B组和C组（P <.005）。
循环加载后拆卸扭矩显著降低。在循环加载之前，锥形螺丝比平头螺丝保持更多的预紧力。循环加载后，锥形和平头螺丝保持的预紧力相等。循环加载后，将基台从种植体固定装置上取下的拉伸力大幅增加。
