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

Abstract

The aim of this study was to test whether posterior zirconia-ceramic (ZC) and metalceramic (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.

A Randomized Clinical Trial Comparing Zirconia and Metal‐Ceramic Three‐Unit Posterior Fixed Partial Dentures: A 5‐Year Follow‐Up

“…To date, only four randomized clinical studies comparing zirconia and MC posterior FPDs have been published . Their results showed similar survival rates of both types of restorations after 3, 4, and 5 years, consistent with the results of this study.…”

“…1,6,17,22 In all four cases, the chipping was observed in FPDs that presented a rough surface, indicating that this clinical factor could be associated with the chipping, as was reported previously. 8,13,14,[19][20][21]36 No chipping was observed in the MC FPDs. No differences were observed between the two groups in any of the technical parameters, except for chipping of the veneering ceramic, which occurred more frequently in zirconia FPDs.…”

“…MC restorations have shown 5-, 10-, and 20-year survival rates of approximately 94.4% to 100%, 90%, and 66.2%, respectively. 13,21,23,[25][26][27][28][29] Zirconia restorations have been shown to have survival rates at 3-and 7-year follow-up evaluations in the range of 83.4% to 100%, [12][13][14][18][19][20][21]23,25,[30][31][32][33][34][35][36] and one study reported a cumulative survival rate of 85% up to 10 years. 37 A systematic review comparing the survival rates of zirconia and MC FPDs showed significant differences; 22 however, a more recent systematic review showed no differences.…”

“…38 The main technical complication of zirconia bilayered FPDs is the chipping or fracture of the veneering ceramic. Previous studies have reported a high prevalence of chipping, with rates between 0% and 35% after up to 10 years of clinical service [12][13][14][18][19][20][21]23,[30][31][32][33][34]36,37 (Table 6); however, framework fractures were rarely reported. 17 In this study, minor cohesive chipping was observed in four zirconia restorations (20%).…”

Load‐Bearing Capacity of Monolithic Zirconia Fixed Dental Prostheses Fabricated with Different Connector Designs and Embrasure Shaping Methods

“…Chip‐off fractures of the veneer porcelain have been commonly and more frequently reported than with metal‐ceramic restorations . This problem might have diminished today, since slow cooling protocols have been introduced at dental labs to avoid subsurface stress formation during sintering of the veneer . Still, the veneer and the interface of the two different materials constitute the weak link of veneered Y‐TZP restorations.…”