One-Year Analysis of Clinical and Radiological Outcomes of Two-Piece Zirconia Compared to Titanium Implants: A...

To evaluate the clinical performance of two-piece zirconia implants with screw-retained abutments compared to titanium implants after 1 year of loading.

In this multicenter, prospective, randomized clinical trial, 61 two-piece zirconia and 61 titanium implants were placed and restored with single crowns. Evaluations were performed at implant placement, crown delivery, and 1-year post-loading. Peri-implant Marginal Bone Loss (MBL), survival rate, early wound healing index, and soft tissue parameters were assessed. Intergroup comparisons of continuous outcomes were performed using Linear Mixed-Effects Models accounting for center and potential confounders. Categorical variables were analyzed using the chi-square or Fisher's exact test. Survival was analyzed using Kaplan-Meier estimates. Significance was set at p < 0.05.

No significant differences were found between the two implant types. Mean MBL from implantation to crown insertion was 1.10 ± 0.78 mm for titanium and 0.94 ± 0.67 mm for zirconia implants. No significant additional bone loss occurred over the subsequent year, with changes of 0.07 ± 0.55 mm and 0.08 ± 0.51 mm for titanium and zirconia, respectively. After 1 year, zirconia implants showed a 100% survival rate, while titanium implants showed 96.5% with two failures. At 1 year, differences in probing depths, plaque accumulation, and Papilla Bleeding Index were not statistically significant.

After 1 year of loading, no statistically significant differences in MBL, implant survival, or peri-implant health were found between zirconia and titanium implants, indicating no clinical superiority. Zirconia implants may therefore be considered a viable alternative in single-tooth implant restorations.

The study is registered at the German Clinical Trial Register (No. DRKS 00013209) as well as at the Federal Office of Public Health's (FOPH) portal for human research in Switzerland (kofam.ch).