Monolithic Zirconia Versus Porcelain-Fused-To-Metal Implant- Supported Fixed Dental Prostheses in the Posterior Region: 1- Year Results of a Randomized Controlled Clinical Trial.

Purpose

To compare the early clinical, biological, and technical outcomes of three-unit implant-supported fixed dental prostheses (iFDPs) fabricated from monolithic zirconia (MonoZR) versus porcelain-fused-to-metal (PFM) in the posterior region.

Methods

In this prospective, superiority randomized controlled clinical trial, partially edentulous patients requiring three-unit posterior iFDPs were randomly allocated to receive either MonoZR or PFM restorations. A total of 52 patients were planned for enrollment; however, 55 patients ultimately received iFDPs. The primary outcome was the rate of ceramic fractures, assessed using USPHS criteria. Secondary outcomes included biological complications, marginal bone level changes, peri-implant soft tissue parameters, and prosthetic performance. All outcomes were evaluated descriptively at the 1-year follow-up, with baseline defined as the time of iFDP insertion.

Results

At the 1-year follow-up, no implant failures were observed. Ceramic fractures were observed in two PFM restorations (n = 2) and in none of the MonoZR restorations. All fractures were minor and managed by polishing, and no restoration required replacement. Marginal bone loss was limited in both groups and remained within clinically acceptable ranges. Peri-implant soft tissue parameters showed no clinically relevant differences between groups. USPHS evaluations indicated satisfactory early prosthetic performance for both restorative concepts, with all restorations rated as clinically acceptable.

Conclusion

At the 1-year follow-up, both the MonoZR and PFM restorative concepts demonstrated favorable clinical and radiographic outcomes. Two ceramic fractures were observed in the PFM group and none in the MonoZR group; however, the limited number of events and descriptive nature of the analysis preclude conclusions regarding between-group differences. Long-term follow-up is required to determine whether these findings are maintained over time.