Statement of problem

Clinical studies comparing compatible computer-aided design and computer-aided manufacturing (CAD-CAM) titanium abutments (CAs) and original prefabricated 1-piece titanium abutments (PAs) for posterior fixed dental prostheses (FDPs) on Straumann Tissue Level (STL) implants are sparse.

Purpose

The purpose of this retrospective clinical study was to compare the performance of posterior FDPs supported by CAs and PAs on STL implants after a mean observation period of 7.2 years.

Material and methods

Patients who received STL implants and posterior FDPs by using CAs or PAs between January 2002 and December 2012 and returned for follow-up between January 2017 and September 2018 were included in this study. Technical and biological complications of FDPs were examined and recorded. Radiographs were used for the measurement of marginal bone loss (MBL) of each implant. Variables, complication rates, and MBL of the 2 groups were analyzed by using a generalized estimating equation and multivariable linear mixed model.

Results

Ninety-nine patients with 195 implants in the CA group and 75 patients with 143 implants in the PA group were included. The mean functional time of FDPs was 6.5 ±1.1 years for the CA group and 8.1 ±2.6 years for the PA group. No implant failure was noted in either group. The technical complication rate was 20.8% in the CA group and 26.3% in the PA group. Abutment screw loosening (ASL) was noted in the CA group (8.5%). The decementation rate was significantly higher in the PA group (14.1%) than that in the CA group (3.1%) (adjusted odds ratio=4.40, confidence interval=1.41 to 13.69, P=.011). No significant differences were found between the 2 groups in terms of the rates of ceramic chipping, peri-implantitis, peri-implant mucositis, or mean MBL.

Conclusions

Using CAs or PAs to support posterior FDPs on STL implants has no significant effect on the incidence rate of biological complications. However, a higher ASL rate and a lower decementation rate were noted with CAs than with PAs.

中文翻译：

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两种不同钛基台支撑的后牙固定义齿在组织水平种植体上的回顾性比较

问题陈述

临床研究比较兼容的计算机辅助设计和计算机辅助制造 (CAD-CAM) 钛基台 (CA) 和原始预制一体式钛基台 (PA)，用于在 Straumann 组织水平 (STL) 种植体上进行后固定义齿 (FDP)稀疏。

目的

这项回顾性临床研究的目的是在平均 7.2 年的观察期后，比较由 CA 和 PA 支持的后路 FDP 在 STL 植入物上的性能。

材料与方法

本研究包括在 2002 年 1 月至 2012 年 12 月期间使用 CA 或 PA 接受 STL 植入物和后路 FDP 并在 2017 年 1 月至 2018 年 9 月期间返回随访的患者。检查并记录了 FDP 的技术和生物学并发症。射线照片用于测量每个种植体的边缘骨丢失 (MBL)。采用广义估计方程和多变量线性混合模型分析2组的变量、并发症发生率和MBL。

结果

CA 组 99 名患者有 195 个种植体，PA 组 75 名患者有 143 个种植体。FDP 的平均功能时间 CA 组为 6.5 ±1.1 年，PA 组为 8.1 ±2.6 年。两组均未发现种植体失败。CA 组的技术并发症发生率为 20.8%，PA 组为 26.3%。CA 组 (8.5%) 注意到基台螺钉松动 (ASL)。PA组的衰退率（14.1%）显着高于CA组（3.1%）（调整后的优势比=4.40，置信区间=1.41至13.69，P =0.011）。两组在陶瓷碎裂、种植体周围炎、种植体周围粘膜炎或平均 MBL 发生率方面没有显着差异。

结论

在 STL 植入物上使用 CAs 或 PAs 支持后 FDPs 对生物并发症的发生率没有显着影响。然而，与 PA 相比，CA 具有更高的 ASL 率和更低的衰退率。