Ceramic implants instead of titanium ones — healthier or just more expensive?

Aim of the study: Titanium currently has a well-established position as the gold standard for manufacturing dental implants; however, it is not free of flaws. Mentions of possible soft-tissue discoloration, corrosion, and possible allergic reactions have led to the development of zirconia dental implants.

Results: Zirconia's biocompatibility and ability to osseointegrate appear unquestionably good. Although some of its mechanical properties are, in fact, inferior to those of titanium, the benefits seem to outweigh the drawbacks. Zirconia implants show very good success rates in clinical research. This is partly due to available surface treatment methods, including changes to nanotopography, which improve wettability, bone-to-implant contact, and osseointegration in general.

Aim of the study: A multitude of biomaterials have been used for the production of implants through the years. Titanium or titanium alloy have been regarded as the 'gold standard' for years.

Results: Short-term study results for contemporary zirconia implants are promising and comparable to those for titanium implants. Nevertheless, the material is relatively brittle and susceptible to surface defects. However, no long-term clinical results exist, and possible complications are unknown. Long-term clinical research is needed before the routine use of zirconia implants can be endorsed.

Aim of the study: The main goal of this review is to provide an in-depth description of published work on the application of zirconia for dental implants and restorations on titanium implants, with an emphasis on clinical studies from the past dozen years with at least 1-year follow-up.

Results: No clear superiority has been documented for zirconia implants compared with titanium implants in biocompatibility, osteoconductivity, physical properties, or allergenicity, despite an aesthetic benefit. Although short-term studies have been promising, larger multicenter, longitudinal, and randomized clinical trials with success data are needed to validate zirconia as a viable alternative to titanium implants and their design. Zirconia abutments with a titanium base have shown a high survival rate and no difference from metal. Bilayered zirconia ceramic restorations are a valid treatment alternative to metal-ceramic implant restorations for single crowns, with similar biological complications and improved aesthetics. Monolithic zirconia restorations show promise for addressing chipping in bilayered ceramic restorations, but longer-term studies are needed, and their aesthetics need to be improved.

Aim of the study: 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.

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. Mean bleeding-on-probing values decreased continuously 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 as between 6 and 24 months (p = 0.002 and p = 0.003, respectively). Over 24 months, two-piece ZrO₂ implants showed a 100% survival rate with no observed fractures. MBL was reduced, especially at augmented sites. The data presented support the short-term suitability of this implant system for single-unit restorations.

Aim of the study: Optimized surface properties are a pivotal factor for dental ceramic implants and overall implant success. After grit-blasting and spray-coating Aluminum Toughened Zirconia (ATZ) ceramic samples with a glass solder, the biological cell response was examined and compared to uncoated and solely grit-blasted samples of the same ceramic.

Results: No toxic effects were observed for either coated or uncoated ATZ samples in direct or indirect tests, as assessed by live/dead staining. Differentiation and viability assays with HDPCs and L929 mouse fibroblasts showed no toxicity, and osteogenic differentiation was not impaired by the coating. Hemocompatibility testing with human whole blood revealed similar results for coated and uncoated ceramic specimens, with no hemolysis or adverse effects on standard hematological parameters. The glass solder coating was cytocompatible and hemocompatible under the tested in vitro conditions and did not impede osteogenic differentiation. These findings indicate that it can serve as a suitable substrate for the proliferation and spreading of L929 fibroblasts and HDPCs, with potential benefits for improving dental ceramic implant surfaces.