Long-term Clinical Outcomes and Cost-Effectiveness of Full-Arch Implant-Supported Zirconia-Based and Metal-Acrylic Fixed Dental Prostheses: A Retrospective Analysis

Purpose: To provide a long-term comparison of metal-acrylic and zirconia implant-supported fixed complete dental prostheses. Materials and Methods: Patients treated with a metal-acrylic or zirconia fixed implant prosthesis with a minimum 5-year follow-up were included. All complications were registered, along with events such as peri-implantitis and implant failure. Survival and all costs associated with the prostheses were assessed to provide an overall evaluation of each type of fixed implant prosthesis protocol. Results: Seventy-four rehabilitated arches (43 metal-acrylic, 31 zirconia, mean follow-up: 8.7 ± 3.37 years) were included. Delayed complications accompanied the metal-acrylic prostheses more frequently. In both groups, single tooth chipping/fracture was the most prominent minor complication, and incidence of multiple teeth and framework fracture was the most frequent major complication. Zirconia fixed implant prostheses demonstrated higher prosthetic survival rates than the metal-acrylic prostheses (93.7% ± 5.5% at 5 years vs 83.0% ± 11.1%). No difference was observed for peri-implantitis or implant failure. The initial cost for zirconia prosthesis fabrication was significantly higher than metal-acrylic hybrids (an estimated difference of $7,829 [P .001]); however, due to reduced complication rates for the zirconia fixed implant prosthesis, maintenance and treatment for complications did not greatly differ between groups. Conclusion: Within the limitations, zirconia fixed implant prostheses presented higher initial costs than metal-acrylic hybrids, however, with satisfactory outcomes, reduction of overall complications, and superior survival rates. Keywords: CAD/CAM, ceramics, dental implants, fixed implant prostheses, zirconia