Statement of problem

Published data have shown that a mechanical surface treatment of titanium surfaces increases bonding potential. However, most of the studies are based on shear or tensile tests performed on flat-surfaced specimens and do not take into consideration the retention given by the titanium base (ti-base) axial walls and the thermomechanical loading seen in a clinical setting.

Purpose

The purpose of this in vitro study was to evaluate the influence of different airborne-particle abrasion (APA) methods of the ti-base surface on the stability of the bonded interface and retention forces between these titanium bases and lithium disilicate crowns after thermomechanical aging.

Material and methods

Sixty internal connection implants (Conelog) were restored with lithium disilicate crowns and bonded to the corresponding ti-bases (Conelog). The ti-bases were divided into 4 groups (n=15), 3 experimental groups applying different APA methods, 30-μm silica-modified Al₂O₃ particles (CoJet) (30-SiO-AlO), 50-μm Al₂O₃ (Cobra Aluoxyd) (50-AlO), 110-μm silica-modified Al₂O₃ particles (Rocatec Plus) (110-SiO-AlO), and 1 control group (NoT). Ti-bases were airborne-particle abraded (10 seconds, 0.25 MPa at a 10-mm distance) under standardized conditions in a custom-made APA device. All crowns were cemented with a resin cement (Multilink Hybrid Abutment). After aging (1 200 000 cycles, 49 N, 1.67 Hz; 5 °C-55 °C, 120 seconds), all specimens were assessed for the presence of bond failures by optical microscopy (×50). The retention forces (N) were tested by using a pull-off test (0.5mm/min). Modes of failure were classified (Type 1, 2, or 3). An additional ti-base representing each group was prepared for surface roughness (μm) calculation (Ra, Rc, Rz) with a noncontact laser profilometer, and representative scanning electron microscope (SEM) images were recorded (×1000). Chi-squared tests were performed to analyze the bonded interface failure and modes of failure, and a Kruskal-Wallis test was selected to evaluate retention force values (α=.05).

Results

The percentages of bonding failure after aging were 73.3% (NoT), 40% (30-SiO-AlO), 6.7% (50-AlO), and 40% (110-SiO-AlO). The stability of the bonded interface was influenced by the APA method applied (P<.05). Mean ±standard deviation retention force values varied from 206.3 ±86.3 N (NoT) to 420 ±139.5 N (50-AlO), and the differences between these 2 groups were significant (P<.05). Modes of failure were predominantly Type 2 (30-SiO-AlO; 50-AlO; 110-SiO-AlO) and Type 3 (NoT).

Conclusions

Airborne-particle abrasion of the titanium surface increased the bond stability and retention forces between the ti-base and the respective crown. The use of 50-μm Al₂O₃ provided the most stable bonded interface among the different treatments.

中文翻译：

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人工老化后钛基基台空气颗粒磨损对粘接界面稳定性和牙冠固位力的影响

问题陈述

已发表的数据表明，钛表面的机械表面处理增加了粘合潜力。然而，大多数研究是基于对平面试样进行的剪切或拉伸试验，并没有考虑钛基 (​​ti-base) 轴向壁提供的保持力和临床环境中看到的热机械载荷。

目的

这项体外研究的目的是评估钛基表面的不同空气颗粒磨损 (APA) 方法对热机械老化后这些钛基和二硅酸锂牙冠之间的粘合界面稳定性和保持力的影响。

材料与方法

用二硅酸锂牙冠修复了 60 个内部连接种植体 (Conelog)，并与相应的钛基 (Conelog) 结合。钛基分为4组（n=15），3个实验组应用不同的APA方法，30-μm二氧化硅改性Al ₂ O ₃颗粒（CoJet）（30-SiO-AlO），50-μm Al ₂ O ₃ (Cobra Aluoxyd) (50-AlO)，110-μm 二氧化硅改性的 Al ₂ O ₃颗粒 (Rocatec Plus) (110-SiO-Al2O) 和 1 个对照组 (NoT)。在标准条件下，在定制的 APA 设备中对钛基进行了空气颗粒研磨（10 秒，0.25 兆帕，距离为 10 毫米）。所有牙冠均使用树脂粘固剂（Multilink Hybrid Abutment）粘接。老化（1 200 000 次循环，49 N，1.67 Hz；5 °C-55 °C，120 秒）后，通过光学显微镜（×50）评估所有样品是否存在粘合失效。保持力 (N) 通过使用拉脱测试 (0.5mm/min) 进行测试。故障模式被分类（类型 1、2 或 3）。为使用非接触式激光轮廓仪计算表面粗糙度 (μm) (Ra、Rc、Rz) 准备了代表每组的额外钛基，并记录了代表性扫描电子显微镜 (SEM) 图像 (×1000)。

结果

老化后键合失败的百分比为 73.3% (NoT)、40% (30-SiO-Al2O)、6.7% (50-Al2O) 和 40% (110-SiO-Al2O)。键合界面的稳定性受所应用的 APA 方法的影响 ( P <.05)。平均±标准偏差保持力值从 206.3 ±86.3 N (NoT) 到 420 ±139.5 N (50-Al2O) 不等，这两组之间的差异显着 ( P <.05)。失效模式主要是类型 2（30-SiO-Al2O；50-Al2O；110-SiO-Al2O）和类型 3（NoT）。

结论

钛表面的空气颗粒磨损增加了钛基和相应牙冠之间的粘合稳定性和保持力。50-μm Al ₂ O _{3 的使用}提供了不同处理中最稳定的键合界面。