Evaluation of all-ceramic and metal-ceramic fixed dental prostheses: a meta-analysis of randomized controlled trials

To systematically review the randomized controlled trials (RCTs) and compare the survival rates and complications of all-ceramic fixed dental prostheses (FDPs) with those of metal-ceramic FDPs. Eligible studies were retrieved in relevant electronic databases from their inception to June 8th, 2016. Then, quality of the included studies was assessed using Cochrane Collaboration’s tool. Heterogeneity across the studies was determined based on Cochrane Q and I2 statistic. Risk ratios (RR) and its 95% confidence intervals (CIs) were used as a measure of effect size to pool outcomes. A total of 7 RCTs with 350 participants (178 applied all-ceramic FDPs and 172 applied metal-ceramic FDPs) were included in this study. The low risk bias of all included studies suggested high qualities. As a result, all-ceramic FDPs showed a comparable survival rate and copings fracture frequency with those of metal-ceramic FDPs. Although without significance (P > 0.05), all-ceramic FDPs had higher occurrences of crowns replacement (RR = 3.20, 95% CI, 0.54 to 18.97), veneering ceramic chipping (RR = 1.87, 95% CI, 0.94 to 3.72) and rough surface (RR = 3.33, 95% CI, 0.98 to 11.35) than metal-ceramic FDPs. It is suggested that all-ceramic FDPs have similar high survival rate and low copings fracture frequency as metal-ceramic FDPs. However, occurrences of other complications, ceramic veneer chipping fractures, crown replacement and rough surface, might be higher in all-ceramic FDPs than metal-ceramic. The alternative use of all-ceramic FDPs should be cautious. More RCTs with large samples are needed to confirm these findings.