Ricomini Filho Antônio Pedro, Fernandes Frederico Silva de Freitas, Straioto Fabiana Gouveia, da Silva Wander José, Del Bel Cury Altair Antoninha
Department of Prosthodontics and Periodontology, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil.
Braz Dent J. 2010;21(2):123-9. doi: 10.1590/s0103-64402010000200006.
Preload loss can favor the occurrence of implant-abutment interface misfit, and bacterial colonization at this interface may lead to implant failure. The aim of this study was to evaluate the preload loss and bacterial penetration through the implant-abutment interface of conical and external hexagon connection systems subjected to thermal cycling and mechanical fatigue (TM). Four different implant-abutment connection systems were evaluated (n=6): external hexagon with universal post, Morse taper with universal post, Morse taper with universal post through bolt, and locking taper with standard abutment. The assemblies (implant-abutment) were subjected to a thermal cycling regimen (1,000 cycles of 5 degrees C and 55 degrees C) and to mechanical fatigue (1.0 million cycles, 1.0 Hz, 120 N). The assemblies were immersed in Tryptic Soy + Yeast Extract broth containing Streptococcus sanguinis and incubated at 37 degrees C and 10% CO(2) for 72 h. Detorque values were recorded. The bacterial penetration was assessed and the abutments were observed by scanning electron microscopy. The preload data were analyzed statistically by two-way ANOVA and Tukey's test at 5% significance level. All screw abutment systems showed significantly higher (p<0.05) detorque values when subjected to TM and all conical systems presented bacterial penetration. The results show no relationship between the preload loss and the bacterial penetration.
预载损失可能会促进种植体-基台界面不匹配的发生，并且该界面处的细菌定植可能导致种植失败。本研究的目的是评估经过热循环和机械疲劳（TM）处理的锥形和外六角连接系统的种植体-基台界面的预载损失和细菌渗透情况。评估了四种不同的种植体-基台连接系统（n = 6）：带通用桩的外六角、带通用桩的莫氏锥度、带贯穿螺栓通用桩的莫氏锥度以及带标准基台的锁定锥度。组件（种植体-基台）接受热循环方案（5℃和55℃的1000个循环）和机械疲劳（100万个循环，1.0Hz，120N）。将组件浸入含有血链球菌的胰蛋白胨大豆 + 酵母提取物肉汤中，并在37℃和10%二氧化碳条件下孵育72小时。记录拧松扭矩值。评估细菌渗透情况，并通过扫描电子显微镜观察基台。预载数据通过双向方差分析和Tukey检验进行统计学分析，显著性水平为5%。所有螺丝基台系统在经受TM时均显示出显著更高（p < 0.05）的拧松扭矩值，并且所有锥形系统均出现细菌渗透。结果表明预载损失与细菌渗透之间没有关系。
