Statement of problem

Internal conical connections have become the primary choice for implant-supported restorations. However, studies that identified the risk indicators for mechanical complications and diagnosed the prognosis of the implant-supported restorations are lacking.

Purpose

The purpose of this retrospective clinical study was to evaluate the incidence and consequences of mechanical complications in components of internal conical connection implants and to analyze the risk indicators.

Material and methods

A total of 428 patients with 898 internal conical connection implants were included in the study, and mechanical complications over the 14-year observation period were evaluated. The Cox proportional hazard regression model was used to analyze significant effects on mechanical complications, which were presented as hazard ratio and 95% confidence interval.

Results

Mechanical complications occurred in 430 (47.9%) implants and 248 (57.9%) patients: screw loosening (46.4% of implants, 56.8% of patients); screw fracture (2.6% of implants, 4.4% of patients); abutment fracture (11.4% of implants, 21.3% of patients); and implant fracture (3.5% of implants, 5.4% of patients). Implant restorations replacing molars showed the highest risk for mechanical complication (hazard ratio 12.82; 95% confidence interval 2.73-60.31) and for fracture of all components. Men had a higher risk of mechanical complication than women (hazard ratio 2.00; 95% confidence interval 1.55-2.59), and the risk of fracture was higher in all components. With increased splinted implants, the risk of mechanical complication (hazard ratio 0.67; 95% confidence interval 0.49-0.93) and component fracture (hazard ratio 0.73; 95% confidence interval 0.29-0.89) decreased. Gold screws had a lower risk of screw loosening (hazard ratio 0.74; 95% confidence interval 0.58-0.94) than titanium screws, but a higher risk of fracture (hazard ratio 3.45; 95% confidence interval 1.42-8.36). The smaller the implant diameter, the higher the risk of implant fracture (hazard ratio 0.01; 95% confidence interval 0.00-0.05).

Conclusions

Abutments were most frequently fractured among the components of internal conical connection type implants. Molar implant-supported restorations and male patients had higher risks of mechanical complications, and as the number of splinted implants in a prosthesis increased, the risk decreased. Gold screws showed less risk of screw loosening and higher risk of fracture than titanium screws. Narrow-diameter implants had a higher risk of fracture.

中文翻译：

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使用内部锥形连接种植体的种植体支持修复体的机械并发症：一项 14 年的回顾性研究

问题陈述

内部锥形连接已成为种植体支持修复体的主要选择。然而，缺乏确定机械并发症风险指标和诊断种植体支持修复体预后的研究。

目的

本回顾性临床研究的目的是评估内部锥形连接种植体组件机械并发症的发生率和后果，并分析风险指标。

材料与方法

该研究共纳入了 428 名患者和 898 颗内部锥形连接种植体，并评估了 14 年观察期内的机械并发症。Cox 比例风险回归模型用于分析对机械并发症的显着影响，以风险比和 95% 置信区间表示。

结果

机械并发症发生在 430 名 (47.9%) 种植体和 248 名 (57.9%) 患者中：螺钉松动（46.4% 的种植体，56.8% 的患者）；螺钉断裂（2.6% 的种植体，4.4% 的患者）；基台断裂（11.4% 的种植体，21.3% 的患者）；种植体骨折（3.5% 的种植体，5.4% 的患者）。替换磨牙的种植体修复显示机械并发症（风险比 12.82；95% 置信区间 2.73-60.31）和所有组件断裂的风险最高。男性发生机械并发症的风险高于女性（风险比 2.00；95% 置信区间 1.55-2.59），并且所有部件的骨折风险都更高。随着夹板植入物的增加，机械并发症的风险（风险比 0.67；95% 置信区间 0.49-0.93）和组件断裂（风险比 0.73；95% 置信区间 0. 29-0.89) 下降。与钛螺钉相比，金螺钉的螺钉松动风险较低（风险比 0.74；95% 置信区间 0.58-0.94），但骨折风险较高（风险比 3.45；95% 置信区间 1.42-8.36）。种植体直径越小，种植体断裂的风险越高（风险比 0.01；95% 置信区间 0.00-0.05）。

结论

在内部锥形连接型种植体的组件中，基台最常断裂。磨牙种植体支持的修复体和男性患者发生机械并发症的风险更高，并且随着假体中夹板种植体数量的增加，风险降低。与钛螺钉相比，金螺钉的螺钉松动风险更小，骨折风险更高。窄直径种植体的骨折风险更高。