Clinical outcomes of a two-piece zirconia dental implant system

BACKGROUND: Data on market-available two-piece zirconia (ZrO₂) dental implants are limited. Therefore, the aim of this retrospective study was to evaluate the clinical performance of a commercially available ZrO₂ implant system over a 24-month period. MATERIALS AND METHODS: In a single private dental office, 35 patients received 63 two-piece ZrO₂ implants for the support of single crowns (SC), fixed dental prostheses (FDP), and overdentures between September 2017 and October 2021. To ensure cohort homogeneity, 31 patients, which received 44 implants to support SCs, were selected for statistical analysis. An anonymized database was used to examine survival and complication rates, marginal bone loss (MBL), and soft tissue parameters. Patients were followed within a defined recall period of at least two years. Descriptive statistics (95% CI) were calculated for MBL, with paired t-tests and one-way ANOVA for comparisons. Associations and clinical parameters were analyzed using Chi-square/Fisher's exact, paired t-test, and Wilcoxon tests (p ≤ 0.05). RESULTS: During the observation period, no implant losses or implant fractures occurred. The mean MBL was 0.24 ± 0.58 mm at 6 months, 0.18 ± 0.62 mm at 12 months, and 0.20 ± 0.66 mm at 24 months. These values were statistically within the range of random variation. MBL differed between the maxilla and mandible, but not significantly. Probing depths increased significantly over time but did not exceed 2.78 ± 0.26 mm. Bleeding on probing mean values showed a continuous decrease from 9.1 ± 13.7% at baseline to 1.1 ± 4.3% after 24 months, with significant differences between baseline and 24 months, as well from 6 to 24 months (p = 0.002 and p = 0.003 respectively). CONCLUSION: Over 24 months, two-piece ZrO₂ implants exhibited a 100% survival rate with no observed fractures. MBL was reduced, especially in augmented sites. The presented data support the short-term suitability of this implant system for single-unit restorations. CLINICAL TRIAL NUMBER: Not applicable.