Anderson James D
Division of Prosthodontics, Faculty of Dentistry, Toronto, Ontario, Canada.
Evid Based Dent. 2005;6(4):96-7. doi: 10.1038/sj.ebd.6400365.
PubMed (1966-April 2004) provided the primary data source along with the bibliographies from identified articles and reviews. A manual search of two relevant journals (Clinical Implant Dentistry and Related Research, Clinical Oral Implants Research, International Journal of Oral & Maxillofacial Implants, International Journal of Periodontics and Restorative Dentistry, International Journal of Prosthodontics, Journal of Clinical Periodontology, Journal of Periodontology and Journal of Prosthetic Dentistry published; published 2001-2003) provided a further source of data.
Because there were no randomised controlled trials (RCT) that compared fixed partial dentures (FPD) with and without cantilever extensions, other studies were selected if they met the following criteria: were published in the English language; were prospective and retrospective cohort studies; had a mean follow-up of >5 years; included patients who were clinically examined at follow-up; and reported details on suprastructures and described at least one-third of reconstructions as FPD.
Two independent reviewers screened articles for inclusion. Disagreements were resolved by discussion and agreement determined by kappa. Two reviewers extracted data on the survival and success of the reconstructions and on biological and technical complications. Failure and complication rates were calculated by dividing the number of events by the total exposure time.
Three prospective and 10 retrospective cohort studies incorporating 700 patients and 816 FPD were included. The mean number of cantilever extensions ranged from 1.1 to 6.0. Meta-analyses gave an estimated survival, after 10 years, of 81.8% [95% confidence interval (CI), 78.2-84.9] and a proportion success of 63% (95% CI, 54.7-70.2). Considering biological complications using Poisson model analyses, the estimated rate of FPD lost because of caries after 10 years was 3.1% (95%CI, 1.0-8.8) and that for loss of vitality was 32.6% (95% CI, 13.9-64.9). The rate of FPD lost because of periodontitis was 1% (95% CI, 0.3-3.0). Cumulative 10-year complication rates were: 2.9% (95% CI, 1.7-5.0) for fracture of abutment tooth; 2.4% (95% CI, 0.6-9.8) for rate of loss as a result of abutment fracture; 16.1% (95% CI, 8.8-28.4) for loss of retention; and 5.9% (95% CI, 3.3-10.4) for material complications.
Success and survival rates for cantilever FPD are poorer than those for conventional FPD and this is accompanied by frequent biological and technical complications.
PubMed（1966年至2004年4月）是主要数据来源，同时还参考了已识别文章和综述的参考文献。对两本相关期刊（《临床种植牙科及相关研究》《临床口腔种植研究》《国际口腔颌面种植杂志》《国际牙周病学与修复牙科学杂志》《国际口腔修复学杂志》《临床牙周病学杂志》《牙周病学杂志》和《口腔修复学杂志》；2001年至2003年出版）进行手工检索，提供了进一步的数据来源。
由于没有比较有无悬臂延伸的固定局部义齿（FPD）的随机对照试验（RCT），若其他研究符合以下标准则被选中：以英文发表；为前瞻性和回顾性队列研究；平均随访时间>5年；纳入随访时接受临床检查的患者；报告上部结构的详细信息，并将至少三分之一的修复体描述为FPD。
两名独立评审员筛选纳入的文章。分歧通过讨论解决，一致性由kappa确定。两名评审员提取关于修复体存活和成功以及生物学和技术并发症的数据。失败率和并发症率通过将事件数除以总暴露时间来计算。
纳入了3项前瞻性和10项回顾性队列研究，涉及700名患者和816个FPD。悬臂延伸的平均数量在1.1至6.0之间。荟萃分析得出，10年后估计存活率为81.8%[95%置信区间（CI），78.2 - 84.9]，成功率为63%（95%CI，54.7 - 70.2）。使用泊松模型分析考虑生物学并发症，10年后因龋齿导致FPD丧失的估计率为3.1%（95%CI，1.0 - 8.8），因活力丧失的为32.6%（95%CI，13.9 - 64.9）。因牙周炎导致FPD丧失的率为1%（95%CI，0.3 - 3.0）。10年累计并发症率为：基牙骨折2.9%（95%CI，1.7 - 5.0）；因基牙骨折导致丧失的率2.4%（95%CI，0.6 - 9.8）；固位丧失16.1%（95%CI，8.8 - 28.4）；材料并发症5.9%（95%CI，3.3 - 10.4）。
悬臂式FPD的成功率和存活率低于传统FPD，且伴有频繁的生物学和技术并发症。
