Theoharidou Anna, Petridis Haralampos P, Tzannas Konstantinos, Garefis Pavlos
Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece.
Int J Oral Maxillofac Implants. 2008 Jul-Aug;23(4):681-90.
The purpose of this study was to systematically review clinical studies on the incidence of abutment screw loosening in single-implant restorations with different implant-abutment connection geometries.
The literature search was conducted using several electronic databases. Specific terms were used for the database search, which spanned the years 1990 to 2006. The search was augmented by using the option of "related articles" as well as hand searching of references and relevant journals. Relevant studies were selected according to predetermined inclusion and exclusion criteria. Agreement between reviewers was determined by using Cohen's kappa coefficients. Three-year complication-free rates (survival proportions) were calculated with the aid of a survival function, assuming constant failure rates. Summary estimates per group for complication-free rate after 3 years (M-estimator) were calculated using Tukey's biweight estimator.
The initial database search yielded 1,526 relevant titles. After the subsequent filtering process, 27 studies were finally selected. Interexaminer agreement ranged from good to perfect. The external-connection group comprised 12 studies following 586 single-implant restorations for a mean follow-up time that ranged from 3 to 5 years. The estimated percent of complication-free single-implant restorations after 3 years was 97.3% (95% CI: 95.6-98.3). The internal connection group comprised 15 studies following 1,113 single-implant restorations for a mean follow-up time that ranged from 3 to 10 years. The estimated percentage of complication-free single-implant restorations after 3 years was 97.6% (95% CI: 96.5-98.3).
The results show that abutment screw loosening is a rare event in single-implant restorations regardless of the geometry of implant-abutment connection, provided that proper antirotational features and torque are employed.
本研究旨在系统回顾关于不同种植体-基台连接几何形状的单颗种植体修复中基台螺钉松动发生率的临床研究。
使用多个电子数据库进行文献检索。数据库检索使用了特定术语，检索时间跨度为1990年至2006年。通过使用“相关文章”选项以及手动检索参考文献和相关期刊来扩充检索范围。根据预先确定的纳入和排除标准选择相关研究。使用科恩kappa系数确定审阅者之间的一致性。借助生存函数计算三年无并发症发生率（生存比例），假设失败率恒定。使用图基双权估计器计算每组三年后无并发症发生率的汇总估计值（M估计器）。
最初的数据库检索产生了1526个相关标题。经过后续筛选过程，最终选择了27项研究。检查者间一致性从良好到完美。外部连接组包括12项研究，涉及586颗单颗种植体修复，平均随访时间为3至5年。三年后单颗种植体修复无并发症的估计百分比为97.3%（95%可信区间：95.6 - 98.3）。内部连接组包括15项研究，涉及1113颗单颗种植体修复，平均随访时间为3至10年。三年后单颗种植体修复无并发症的估计百分比为97.6%（95%可信区间：96.5 - 98.3）。
结果表明，在单颗种植体修复中，只要采用适当的抗旋转特征和扭矩，无论种植体-基台连接的几何形状如何，基台螺钉松动都是罕见事件。
