Wennström Jan, Zurdo Jose, Karlsson Stig, Ekestubbe Annika, Gröndahl Kerstin, Lindhe Jan
Department of Periodontology, Faculty of Odontology, The Sahlgrenska Academy at Göteborg University, SE 405 30 Göteborg, Sweden.
J Clin Periodontol. 2004 Dec;31(12):1077-83. doi: 10.1111/j.1600-051X.2004.00603.x.
The aim of this study was to retrospectively analyze whether the inclusion of cantilever extensions increased the amount of marginal bone loss at free-standing, implant-supported, fixed partial dentures (FPDs) over a 5-year period of functional loading.
The patient material comprised 45 periodontally treated, partially dentate patients with a total of 50 free-standing FPDs supported by implants of the Astra Tech System. Following FPD placement (baseline) the patients were enrolled in an individually designed supportive care program. A set of criteria was collected at baseline to characterize the FPDs. The primary outcome variable was change in peri-implant bone level from the time of FPD placement to the 5-year follow-up examination. The comparison between FPDs with and without cantilevers was performed at three levels: FPD level, implant level, and surface level. Bivariate analysis was performed by the use of the Mann-Whitney U-test and stepwise regression analysis was utilized to evaluate the potential influence of confounding factors on the change in peri-implant bone level.
The overall mean marginal bone loss for the implant-supported FPDs after 5 years in function was 0.4 mm (SD, 0.76). The bone level change at FPDs placed in the maxilla was significantly greater than that for FPDs in the mandible (0.6 versus 0.2 mm; p<0.05). No statistically significant differences were found with regard to peri-implant bone level change over the 5 years between FPDs with and without cantilevers at any of the levels of comparisons. The multivariate analysis revealed that the variables jaw of treatment and smoking had a significant influence on peri-implant bone level change on the FPD level, but not on the implant or surface levels. The model explained only 10% of the observed variance in the bone level change.
The study failed to demonstrate that the presence of cantilever extensions in an FPD had an effect on peri-implant bone loss.
本研究旨在回顾性分析在5年的功能加载期内，悬臂延长部分的纳入是否会增加独立式、种植体支持的固定局部义齿（FPD）的边缘骨吸收量。
患者材料包括45名接受过牙周治疗的部分牙列缺损患者，共有50个由Astra Tech系统种植体支持的独立式FPD。在放置FPD（基线）后，患者被纳入一个单独设计的支持性护理项目。在基线时收集一组标准以表征FPD。主要结局变量是从FPD放置时到5年随访检查时种植体周围骨水平的变化。对有悬臂和无悬臂的FPD在三个层面进行比较：FPD层面、种植体层面和表面层面。使用Mann-Whitney U检验进行双变量分析，并利用逐步回归分析来评估混杂因素对种植体周围骨水平变化的潜在影响。
功能5年后，种植体支持的FPD的总体平均边缘骨吸收为0.4mm（标准差，0.76）。在上颌放置的FPD的骨水平变化显著大于在下颌放置的FPD（0.6对0.2mm；p<0.05）。在任何比较层面上，有悬臂和无悬臂的FPD在5年期间的种植体周围骨水平变化均未发现统计学上的显著差异。多变量分析显示，治疗颌骨和吸烟变量对FPD层面的种植体周围骨水平变化有显著影响，但对种植体或表面层面无影响。该模型仅解释了观察到的骨水平变化方差的10%。
该研究未能证明FPD中悬臂延长部分的存在对种植体周围骨丢失有影响。
