A 5‐year randomized controlled trial comparing zirconia‐based versus metal‐based implant‐supported single‐tooth restorations in the premolar region

OBJECTIVE: To compare 5‐year biological, technical, aesthetic, and patient‐reported outcomes of single‐tooth implant‐supported all‐ceramic versus metal‐ceramic restorations. MATERIALS AND METHODS: Thirty patients with 63 premolar agenesis participated in the 5‐year follow‐up. The prosthetic treatment on single‐tooth implants was randomly assigned to all‐ceramic crowns on zirconia abutments (AC = 31) or metal‐ceramic crowns on metal abutments (MC = 32). All patients were recalled to clinical examinations at baseline, 1, 3, and 5 years after prosthetic treatments. Biological, technical, and aesthetic outcomes including complications were clinically and radiographically registered. The patient‐reported outcomes were recorded using OHIP‐49 questionnaire before treatment and at each follow‐up examination. RESULTS: At the 5‐year examination, the survival rate was 100% for implants and 100% for AC and 97% for MC crowns and abutments. The marginal bone loss after 5 years was minor and not significantly different (p = .056) between AC (mean: 0.3, SD: 1.1) and MC (mean: −0.1, SD: 0.4) restorations. The success rate of the implants based on marginal bone loss was 77.4% for AC‐ and 93.7% for MC restorations. The marginal adaptation was significantly better for MC than for AC restorations (p = .025). The aesthetic outcomes and patient‐reported outcomes between AC and MC restorations were not significantly different. CONCLUSIONS: The biological, aesthetic and patient‐reported outcomes for implant‐supported AC and MC restorations were successful and with no significant difference after 5‐years. The marginal adaptation of the MC crowns cemented on titanium abutments showed a significantly better fit than restorations based on zirconia crowns cemented on zirconia abutments.