10-year randomized trial (RCT) of zirconia-ceramic and metal-ceramic fixed dental prostheses.

OBJECTIVES: To monitor zirconia-ceramic and metal-ceramic posterior FDPs with respect to survival and technical/biological complication rates. MATERIALS AND METHODS: Fifty-eight patients received 76 3- to 5-unit posterior FDPs. The sites were randomly assigned to 40 zirconia-based (ZC) and 36 metal-based (MC) FDPs. FDPs were examined at baseline (cementation), at 6 months, at 1 year and then yearly up to 10 years. Technical outcomes were assessed using modified United States Public Health Service (USPHS) criteria. Biologic outcomes included probing depth, plaque, bleeding on probing and tooth vitality. Statistical analysis was performed applying Kaplan-Meier (KM) estimation, log-rank, Mann-Whitney and Fisher exact test. RESULTS: During the 10-year follow-up thirteen patients (17 FDPs) dropped out and 6 FDPs in 6 patients (5 ZC,1 MC) were considered catastrophic failures for technical and/or biological reasons. Forty-four patients with 53 FDPs (29 ZC, 24 MC) were available for examination. The median observation period was 10.3 years (ZC) and 10.0 years (MC). The 10-year KM survival estimate of ZC FDPs was 91.3% (95%CI:69.5;97.8) and 100% of MC FDPs. Minor chipping of the veneering ceramic and occlusal wear were found to a similar extent at ZC and MC FDPs. ZC FDPs demonstrated a significantly higher rate of framework fracture, de-bonding, major fractures of the veneering ceramic and poor marginal adaption. Biological outcomes were similar in both groups and between abutment and control teeth. CONCLUSION: At 10 years, ZC and MC posterior FDPs resulted in similar outcomes for the majority of the outcome measures (p > 0.05).

Comparison of Fixed Dental Prostheses with Zirconia and Metal Frameworks: Five-Year Results of a Randomized Controlled Clinical Trial.

PURPOSE: The aim of this study was to test whether posterior zirconia-ceramic (ZC) and metal-ceramic (MC) fixed dental prostheses (FDPs) exhibit similar survival and technical/biologic complication rates. MATERIALS AND METHODS: A total of 58 patients in need of 76 posterior FDPs were randomly assigned to receive 40 ZC and 36 MC FDPs. The restorations were examined at baseline (cementation) and yearly for 5 years. Technical and biologic outcomes were compared. The independent treatment groups were compared with nonparametric Mann-Whitney test for metric variables and with Fisher exact test for categoric data. RESULTS: A total of 52 patients with 40 ZC and 29 MC FDPs were examined at 5 years. No FDP failed during the 5 years; 2 ZC FDPs failed at 65.4 and 73.3 months. Debonding occurred at 3 ZC FDPs. Technical outcomes (modified US Public Health Service criteria) and general periodontal parameters did not show significant differences between ZC and MC FDPs. CONCLUSION: ZC FDPs exhibited similar outcomes to MC FDPs based on 5-year survival estimates. The majority of technical and biologic outcome measures were not significantly different.