Alves Deceles Cristina Costa, de Carvalho Paulo Sérgio Perri, Elias Carlos Nelson, Vedovatto Eduardo, Martinez Elizabeth Ferreira
Oral Implantology, São Leopoldo Mandic Institute and Research Center, Campinas, SP, Brazil.
Materials Science Department, Instituto Militar de Engenharia, Rio de Janeiro, RJ, Brazil.
Clin Oral Investig. 2016 Dec;20(9):2437-2445. doi: 10.1007/s00784-016-1744-0. Epub 2016 Feb 20.
The aim of this in vitro study was to evaluate the mechanical behavior and bacterial microleakage at the implant/abutment-tapered interface following mechanical cycling.
Two groups of screwless (Morse taper) implants (G1 and G2) and two groups of prosthetic screwed implants (G3 and G4) were tested. One group from each model (G2 and G4) were submitted to mechanical cycling, 500,000 cycles per sample, at a load of 120 N at 2 Hz prior to analysis. Microbiological analysis was performed via immersion of all samples in an Escherichia coli-containing suspension, incubated at 37 °C. After 14 days, the abutments were removed from their respective implants, registering the removal force (G1 and G2) or reverse torque (G3 and G4), and the presence of bacterial leakage was evaluated. Scanning electron microscopy (SEM) was performed to analyze the tapered surfaces of the selected samples. The Student t, binomial, and G tests were used for statistical analysis at a 5 % significance level.
The results showed no significant difference between removal force, reverse torque, and contamination values when comparing implants of the same type. However, when the four groups were compared, contamination differed significantly (p = 0.044), with G1 having the least number of contaminated samples (8.3 %). SEM analysis showed superficial defects and damage.
The abutment removal force or torque was not affected by mechanical cycling. Bacterial sealing of the implant/abutment tapered interface was not effective for any condition analyzed. Imprecise machining of implant parts does not allow a sufficient contact area between surfaces to provide effective sealing and prevent bacterial leakage.
The microscopic gap caused by unsatisfactory implant/abutment adaptation, surface irregularities, and plastic deformation of all parts enabled bacterial contamination of the oral implants.
本体外研究的目的是评估机械循环后种植体/基台锥形界面的力学行为和细菌微渗漏情况。
测试了两组无螺钉（莫氏锥度）种植体（G1和G2）以及两组修复用带螺纹种植体（G3和G4）。每个模型中的一组（G2和G4）在分析前先进行机械循环，每个样本500,000次循环，在2赫兹频率下施加120牛的负载。通过将所有样本浸入含大肠杆菌的悬浮液中并在37℃下孵育来进行微生物分析。14天后，将基台从各自的种植体上取下，记录去除力（G1和G2）或反向扭矩（G3和G4），并评估细菌渗漏情况。进行扫描电子显微镜（SEM）分析以观察所选样本的锥形表面。采用学生t检验、二项式检验和G检验进行统计学分析，显著性水平为5%。
比较同一类型的种植体时，去除力、反向扭矩和污染值之间无显著差异。然而，比较这四组时，污染情况有显著差异（p = ？044），G1组受污染样本数量最少（8.3%）。SEM分析显示存在表面缺陷和损伤。
机械循环未影响基台去除力或扭矩。在分析的任何条件下，种植体/基台锥形界面的细菌密封均无效。种植体部件加工不精确导致表面之间没有足够的接触面积，无法提供有效的密封并防止细菌渗漏。
种植体/基台适配不佳、表面不规则以及所有部件的塑性变形所导致的微观间隙会使口腔种植体受到细菌污染。
