Loss of nonvital abutment teeth for removable partial dentures: a systematic review and meta-analysis

Objective:To analyze the loss of nonvital abutment teeth compared to vital abutment teeth supporting removable partial dentures (RPDs). Method and materials: An electronic search was conducted in the Ovid MEDLINE, Embase, and Web of Science databases, and supplemented by a manual search. The search was done to identify clinical studies reporting the loss of nonvital abutment teeth compared to vital abutment teeth for RPDs. The data were extracted from each selected article and meta-analysis was performed using a random effects model to estimate adjusted proportion of abutment loss with RPDs along with 95% confidence interval (CI). Risk of bias assessment was conducted using Cochrane Risk of Bias tools and NewcastleOttawa Scale. The statistical significance was set as P value < .05. Results: A total of 3,898 records were identified from electronic databases and 8 studies were included for quantitative synthesis of 834 subjects with 1,036 RPDs. No additional records were identified through manual search. Among 1,152 nonvital abutment teeth, 123 teeth were lost. The estimate of nonvital abutment loss was 13% (95% Cl 9-18%] The data were statistically significant (P < .0001), and were heterogenous between the studies (chi(2) [df = 7] = 35.9, P < .0001; tau(2) = 0.25, I- (2)= 76.46%). A total of 2,186 vital abutment teeth were compounded where 114 teeth were lost. The estimate of vital abutment loss was 4% (95% CI 2-7%).The data were statistically significant (P < .0001), and were heterogenous between the studies (chi(2) [df = 7] = 23.7, P = .01; tau(2) = 0.56, I-2 = 86.31%).The risk of abutment loss was approximately three times greater with the loss of vitality (odds ratio = 3.04, 95% CI 1.53-6.05; P = .001). In addition, abutment loss was significantly greater with increasing follow-up time (P = .01). None of the included studies were considered to be at high risk of bias. Conclusion: Within the limitations of this systematic review and meta-analysis, the loss of nonvital abutment teeth was significantly greater than that of vital abutment teeth for RPDs. Further research is needed to identify critical factors associated with the loss of nonvital abutment teeth.