UFR of Odontology, Paris 7-Denis Diderot University, Paris, France.
Clin Oral Implants Res. 2011 Nov;22(11):1270-4. doi: 10.1111/j.1600-0501.2010.02102.x. Epub 2011 Feb 24.
Implant-supported overdentures have become the treatment of choice in restoring complete edentulism, but the types of attachment to assure durable retention are a subject of debate. Ball attachments were reported as a simple treatment, but wear of components was responsible for a decrease in retention. The aim of this retrospective study was to measure the wear of the ball abutment or patrix after three different periods of clinical wear.
Sixty-nine specimens of three groups of patrix that were in use for a mean of 12.3 months (group A), 39 months (group B) and 95.6 months (group C) were retrieved from 35 patients and measured on a coordinate measuring machine equipped with a touch trigger probe. Ten unused ball abutments were added as a control (group D). The patrix diameters and any deviation from circularity in different axes were measured.
The diameters of groups A, B and C were significantly different from that of group D (control). No statistically significant differences were found between diameter and circularity variations between groups B and C. The maximal amount of diameter reduction was limited to approximately 30 μm, and 90% of diameter loss at the equator due to wear was reached in group B.
One, 3 and 8 years of clinical wear reduced significantly the diameters of the ball abutments tested, and the maximal amount of wear was reached after 3 years of clinical use.
种植体支持的覆盖义齿已成为修复完全无牙颌的首选治疗方法，但确保持久固位的附着体类型仍存在争议。球附着体被认为是一种简单的治疗方法，但由于部件的磨损，导致保留率下降。本回顾性研究的目的是测量在三个不同临床使用阶段后球基台或母球的磨损情况。
从 35 名患者中取出了三组母球的 69 个样本，每组平均使用 12.3 个月（A 组）、39 个月（B 组）和 95.6 个月（C 组），并用配备有触针探头的坐标测量机进行测量。另外还添加了 10 个未使用的球基台作为对照组（D 组）。测量了母球的直径和不同轴线上的任何非圆度偏差。
A、B 和 C 组的直径与 D 组（对照组）的直径有显著差异。B 组和 C 组之间在直径和圆度变化方面没有发现统计学上的显著差异。直径减小的最大量限制在约 30μm，并且在 B 组中由于磨损导致赤道处的直径损失达到 90%。
经过 1、3 和 8 年的临床使用，测试的球基台直径显著减小，并且在 3 年的临床使用后达到了最大磨损量。
