Pre-Clinical Evaluation of New Zirconia-Based Ceramic Dental Implants

Objectives: Ceramics are an alternative to titanium for aesthetic and metal-free solutions in dental implantology. However, several reports of fractures of 3Y-TZP implants in clinical studies further motivate the search for alternative ceramic materials. Tri-phasic oxide materials based on Ceria-doped zirconia (Ce-TZP) were developed recently to be more reliable and tougher than 3Y-TZP. The aim of this study was to evaluate the pre-clinical performance of screw-shaped sandblasted-etched Ce-TZP-based-ceramic implants in comparison to titanium.
Methods: Twenty-four ceramic and twenty-four titanium screw-shaped sandblasted-etched dental implants were tested in a split-mouth design in six Beagle dogs. Microstructural features and surface topography were investigated by microscopy. Local tissue effects were evaluated at 4 and 13 weeks after implantation through histology. An ANOVA statistical analysis (5% risk; p<0.05) was performed to compare peri-implant quantitative histomorphometric parameters on buccal and lingual sides, including Bone to Implant Contact (BIC) among test groups and time-periods.
Results: Titanium and ceramic implants presented respectively moderate (Sa = 1.21 ± 0.12 µm) and minimal (Sa = 0.68 µm ±0.21) roughness. After 4 and 13 weeks, ceramic implants showed an inflammatory tissue response close to titanium implants. At both time periods there was no significant difference between the titanium and ceramic groups in terms of BIC values (mean ± SD) at the lingual or buccal sides or when combining buccal + lingual BIC values (respectively for titanium and ceramic, 68.4 ± 14.7% and 75.0 ± 13.5% at 4 weeks, and 92.0 ± 8.6% and 86.1 ± 13.8% at 13 weeks).
Conclusions: Within the limits of the present study it can be concluded that newly developed triphasic Ce-TZP-based dental implants have similar biocompatibility and osseointegration to those observed in titanium implants. These results add a pre-clinical substantiation to the potential mechanical benefits of using of these new zirconia-based ceramics in dental implantology.