Purpose: To assess the clinical, technical, and esthetic outcomes of directly veneered zirconia abutments cemented onto nonoriginal titanium bases over a 3-year follow-up.
Materials and Methods: A total of 24 healthy patients with a single missing tooth in the maxilla or mandible (incisors, canines, or premolars) received a two-piece implant with a screw-retained veneered zirconia restoration extraorally cemented onto a titanium base abutment. Baseline measurements and follow-up examinations were performed at 6 months, 1 year, and 3 years following loading. Radiographic, clinical, technical, and esthetic parameters were assessed. Wilcoxon signed rank test was used to analyze the data.
Results: Mean marginal bone levels measured 0.54 ± 0.39 mm (median: 0.47 mm, range: 0.07 to 1.75 mm) at baseline and 0.52 ± 0.39 mm (median: 0.39 mm, range: 0.06 to 1.33 mm) at 3 years. Mean probing depth around the implants increased from 3.0 ± 0.6 mm at baseline to 3.8 ± 0.8 mm at 3 years (P = .001). Bleeding on probing changed from 27.1% ± 20.7% at baseline to 51.5% ± 26.1% at 3 years (P = .001). The mean plaque control record amounted to 11.1% ± 21.2% at baseline and 14.4% ± 13.89% at 3 years (P = .261). Two implants were lost at 3.5 and 30 months postloading due to periimplantitis, resulting in a 91.7% implant survival rate. Patient satisfaction was high at 3 years.
Conclusion: Zirconia restorations cemented onto the tested nonoriginal titanium bases should not be recommended for daily clinical use, as they were associated with significant increases in BOP and PD values and varying marginal bone levels 3 years after placement.
