Int J Prosthodont. 2020 Mar/Apr;33(2):184-191. doi: 10.11607/ijp.6636.
To analyze the current evidence on bone loss in the posterior edentulous mandible restored with complete dentures (CDs), two-implant-supported overdentures (2-IODs), or four-implant-supported overdentures (4-IODs).
A search was conducted in the Ovid MEDLINE, Embase, Web of Science, CINAHL, and Cochrane databases for clinical studies comparing bone loss in posterior edentulous mandibles restored with CDs, 2-IODs, or 4-IODs. A meta-analysis was performed using statistical software to estimate the mean differences in bone loss with 95% CI. The level of significance was set at P < .05.
The search strategy identified 2,806 articles, of which 14 met the inclusion criteria. The meta-analysis included 7 two-arm studies comparing CDs vs 2-IODs or 2-IODs vs 4-IODs. No statistically significant difference was found in bone loss between 2-IODs and CDs (mean difference -0.25 [95% CI -0.85 to 0.36]; P = .43), whereas bone loss was significantly lower with 4-IODs than with 2-IODs (mean difference -0.96 [95% CI -1.86 to -0.06]; P = .04). Overall, the data were highly heterogenous (I > 74%).
4-IODs can benefit the patient by decreasing bone loss in the posterior edentulous mandible. However, 2-IODs may not be superior to CDs in reducing bone loss in the posterior mandible. A validation of these results is needed through well-designed RCTs.
分析使用全口义齿（CDs）、双种植体覆盖义齿（2-IODs）或四种植体覆盖义齿（4-IODs）修复下颌无牙后区骨丢失的现有证据。
在 Ovid MEDLINE、Embase、Web of Science、CINAHL 和 Cochrane 数据库中搜索比较下颌无牙后区使用 CDs、2-IODs 或 4-IODs 修复后骨丢失的临床研究。使用统计软件进行荟萃分析，以估计骨丢失的均数差异和 95%置信区间。显著性水平设为 P <.05。
搜索策略共确定了 2806 篇文章，其中 14 篇符合纳入标准。荟萃分析纳入了 7 项双臂研究，比较了 CDs 与 2-IODs 或 2-IODs 与 4-IODs 的比较。2-IODs 与 CDs 之间的骨丢失无统计学差异（平均差异-0.25 [95%置信区间-0.85 至 0.36]；P =.43），而 4-IODs 与 2-IODs 相比，骨丢失明显更低（平均差异-0.96 [95%置信区间-1.86 至-0.06]；P =.04）。总体而言，数据高度异质（I > 74%）。
4-IODs 可通过减少下颌无牙后区的骨丢失使患者受益。然而，2-IODs 在减少下颌后区的骨丢失方面可能并不优于 CDs。需要通过精心设计的 RCT 来验证这些结果。
