Quintessence Int. 2021;52(5):412-424. doi: 10.3290/j.qi.b912671.
Objective: To analyze the loss of abutment teeth for double crown-retained removable partial dentures (DC-RPDs) compared to clasp-retained removable partial dentures (C-RPDs). Method and materials: A search was conducted in the Ovid MEDLINE, Embase, Web of Science databases, and a manual search. The search was conducted based on the PICO framework with inclusion and exclusion criteria. After extracting the data of selected studies, a meta-analysis was performed to estimate abutment loss with 95% confidence interval (CI). The statistical significance was defined as P < .05, and the heterogeneity of the data was assessed based on the chi-squared test and I2 statistics. Risk of bias assessment was conducted using Cochrane Risk of Bias tool and Newcastle-Ottawa Scale. Results: A total of 4,692 records were identified from electronic databases and 38 studies were included for quantitative synthesis of 3,393 subjects with 13,552 abutment teeth. A total of 1,226 abutment teeth were lost with > 4,016 RPDs. Seven studies were compounded for > 668 C-RPDs (mean follow-up time ≤ 5 years) and six studies for 893 C-RPDs (mean follow-up time < 5 years), where the estimates of abutment loss were 5% (95% CI 2% to 8%) and 8% (95% CI 5% to 13%), respectively. The data were not significantly different (P = .1), and were heterogenous between the studies (τ2 ≥ 0.34, I2 ≥ 87.38%). Thirteen studies were compounded for 1,223 DC-RPDs (mean follow-up time ≤ 5 years) and eight studies for 1,033 DC-RPDs (mean follow-up time > 5 years), where the estimates of abutment loss were 6% (95% CI 5% to 8%) and 12% (95% CI 8% to 18%), respectively. The data were heterogenous (τ2 ≥ 0.17, I2 ≥ 75.86%), and were significantly different between the studies (P = .005). Overall, C-RPDs were not significantly different from DC-RPDs in abutment loss (P ≥ .3). A significant predictor for abutment loss was follow-up time with DC-RPDs (P = .005), where the risk of abutment loss per year was 18% (P = .0001). In contrast, follow-up time was not a significant factor for C-RPDs (P = .1). None of the included studies were at high risk of bias. Conclusion: Within the limitations of the current systematic review and meta-analysis, abutment loss was not significantly different between C-RPDs and DC-RPDs. A significant predictor was follow-up time for DC-RPDs, whereas this factor was not significant for C-RPDs. Further research is needed to investigate critical factors for abutment loss with RPDs.
分析双冠固位可摘局部义齿（DC-RPD）与卡环固位可摘局部义齿（C-RPD）相比基牙的丧失情况。方法与材料：在 Ovid MEDLINE、Embase、Web of Science 数据库中进行检索，并进行手动检索。根据 PICO 框架进行检索，并设定纳入和排除标准。在选择研究的数据提取后，进行荟萃分析以估计 95%置信区间（CI）的基牙丧失情况。统计显著性定义为 P<0.05，并根据卡方检验和 I2 统计评估数据的异质性。使用 Cochrane 偏倚风险工具和纽卡斯尔-渥太华量表进行偏倚风险评估。结果：从电子数据库中确定了 4692 条记录，并对 38 项研究进行了定量综合分析，共纳入了 3393 名受试者的 13552 颗基牙。共有 1226 颗基牙在 4016 个 RPD 中有损失。7 项研究将 668 个 C-RPD 进行复合（平均随访时间≤5 年），6 项研究将 893 个 C-RPD 进行复合（平均随访时间<5 年），基牙丧失的估计值分别为 5%（95%CI 2%至 8%）和 8%（95%CI 5%至 13%）。数据无显著差异（P=0.1），且研究间存在异质性（τ2≥0.34，I2≥87.38%）。13 项研究将 1223 个 DC-RPD 进行复合（平均随访时间≤5 年），8 项研究将 1033 个 DC-RPD 进行复合（平均随访时间>5 年），基牙丧失的估计值分别为 6%（95%CI 5%至 8%）和 12%（95%CI 8%至 18%）。数据存在异质性（τ2≥0.17，I2≥75.86%），且研究间存在显著差异（P=0.005）。总体而言，C-RPD 与 DC-RPD 在基牙丧失方面无显著差异（P≥0.3）。基牙丧失的一个显著预测因素是 DC-RPD 的随访时间（P=0.005），每年基牙丧失的风险为 18%（P=0.0001）。相反，随访时间并不是 C-RPD 的重要因素（P=0.1）。纳入的研究均无高偏倚风险。结论：在本系统评价和荟萃分析的限制范围内，C-RPD 和 DC-RPD 的基牙丧失无显著差异。显著的预测因素是 DC-RPD 的随访时间，而这一因素对 C-RPD 并不重要。需要进一步研究以探讨 RPD 基牙丧失的关键因素。
