A five-year randomised controlled trial comparing zirconia-based versus metal-based implant-supported single-tooth restorations in the premolar region

OBJECTIVES

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 were 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 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= 0.056) between AC (mean: 0.3, SD: 1.1) and MC restorations (mean: -0.1, SD: 0.4). 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=0.025). 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 significantly better fit than restorations based on zirconia crowns cemented on zirconia abutments.