ObjectivesThe objective of this long‐term retrospective study was to evaluate the fracture rate and the risk factors associated with the fracture of 3.3 mm narrow diameter implants (NDIs).Materials and MethodsA total of 524 records of patients rehabilitated with 3.3 mm NDIs between 1997 and 2015 were assessed. Data on patients, implants, and prostheses were collected, and descriptive analysis of the variables was performed. NDIs were separated into 2 groups: “fractured” and “non‐fractured”, and a multilevel logistic regression model was applied to identify the risk factors associated with NDI fracture.ResultsEighty‐four patients were removed from the analysis for interrupting follow‐up or presenting failures other than fractures. Of the 440 patients included (64.66 ± 13.4 years), 272 were females (61.8%), and 168 males (38.2%), and mean follow‐up time was 129 ± 47.1 months. Of the 1428 NDIs, 15 (1.05%) in 9 patients (2.04%) fractured during the studied period. Ten fractures (66.66%) happened in 6 patients (66.66%) showing signs of parafunction. NDI with modified sandblasted, large grit, acid‐etched surface was the only implant variable to show a protective statistical significance (p = .0439).ConclusionsNDI fracture was a rare event in the studied sample. NDIs manufactured with modified sandblasted, large grit, acid‐etched surface may provide extra protection against NDI fracture. Patient‐specific factors and implant characteristics should be carefully considered to limit the risk of fracture of 3.3 mm NDIs.

中文翻译：

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骨折率和与窄直径种植体骨折相关的危险因素：长期回顾性分析


目的这项长期回顾性研究的目的是评估 3.3 mm 窄直径植入物 （NDI） 的骨折率和与骨折相关的危险因素。材料和方法共评估了 524 例 1997 和 2015 年间接受 3.3 mm NDI 康复的患者记录。收集患者、植入物和假体的数据，并对变量进行描述性分析。将 NDI 分为 2 组：“骨折”和“非骨折”，并应用多级 logistic 回归模型来确定与 NDI 骨折相关的危险因素。结果84 例患者因中断随访或出现骨折以外的失败而被排除在分析之外。在纳入的 440 名患者 （64.66 ± 13.4 岁） 中，女性 272 名 （61.8%） 和 168 名男性 （38.2%），平均随访时间为 129 ± 47.1 个月。在 1428 例 NDI 中，9 例患者中有 15 例 （1.05%） 在研究期间发生骨折 （2.04%）。10 例骨折 （66.66%） 发生在 6 例表现出功能异常迹象的患者 （66.66%） 中。具有改性喷砂、大砂砾、酸蚀表面的 NDI 是唯一显示保护性统计显着性的植入物变量 （p = .0439）。结论NDI 骨折在研究样本中是罕见事件。使用改性喷砂、大砂砾、酸蚀表面制造的 NDI 可以提供额外的保护，防止 NDI 断裂。应仔细考虑患者特定因素和植入物特性，以限制 3.3 毫米 NDI 骨折的风险。