Objective

This study aimed to evaluate the fracture load and pattern of customized and non-customized zirconia abutments with Morse-taper connection.

Methods

18 implants were divided into 3 groups according to the abutments used: Zr — with non-customized zirconia abutments; Zrc — with customized zirconia abutments; and Ti — with titanium abutments. To test their load capacity, a universal test machine with a 500-kgf load cell and a 0.5-mm/min speed were used. After, one implant-abutment assembly from each group was analyzed by Scanning Electron Microscopy (SEM). For fractographic analysis, the specimens were transversely sectioned above the threads of the abutment screw in order to examine their fracture surfaces using SEM.

Results

A significant difference was noted between the groups (Zr = 573.7 ± 11.66 N, Zrc = 768.0 ± 8.72 N and Ti = 659.1 ± 7.70 N). Also, the zirconia abutments fractured while the titanium abutments deformed plastically. Zrc presented fracture loads significantly higher than Zr (p = 0.009). All the zirconia abutments fractured below the implant platform, starting from the area of contact between the abutment and implant and propagating to the internal surface of the abutment. All the zirconia abutments presented complete cleavage in the mechanical test. Fractography detected differences in the position and pattern of fracture between the two groups with zirconia abutments, probably because of the different diameters in the transmucosal region.

Significance

Customization of zirconia abutments did not affect their fracture loads, which were comparable to that of titanium and much higher than the maximum physiological limit for the anterior region of the maxilla.

中文翻译：

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定制和非定制氧化锆基台的断裂载荷和破坏模式

客观的

这项研究旨在评估采用莫氏锥度连接的定制和非定制氧化锆基台的断裂载荷和模式。

方法

根据所使用的基台，将18种植入物分为3组：Zr-带有非定制的氧化锆基台；Zrc-具有定制的氧化锆基台；和Ti-含钛基台。为了测试其负载能力，使用了具有500 kgf称重传感器和0.5 mm / min速度的通用测试机。之后，通过扫描电子显微镜（SEM）分析每组中的一个种植体-基台组件。为了进行分形分析，将样品在基台螺丝的螺纹上方横向剖开，以便使用SEM检查其断裂表面。

结果

两组之间存在显着差异（Zr = 573.7±11.66 N，Zrc = 768.0±8.72 N和Ti = 659.1±7.70 N）。同样，氧化锆基台断裂，而钛基台发生塑性变形。Zrc的断裂载荷明显高于Zr（p = 0.009）。从基台和植入物之间的接触区域开始，所有氧化锆基台都在植入物平台下方断裂，并传播到基台的内表面。在机械测试中，所有氧化锆基台均显示出完全的劈裂。分形术检测到两组氧化锆基台之间的骨折位置和模式不同，这可能是由于跨粘膜区域的直径不同所致。

意义

氧化锆基台的定制不会影响其断裂载荷，该断裂载荷与钛的断裂载荷相当，并且远高于上颌前区的最大生理极限。