Zirconium-based metallic glass and zirconia coatings to inhibit bone formation on titanium

Promoted Abutment-Soft Tissue Integration Around Self-Glazed Zirconia Surfaces with Nanotopography Fabricated by Additive 3D Gel Deposition

Introduction

Improving the biological sealing around dental abutments could promote the long-term success of implants. Although titanium abutments have a wide range of clinical applications, they incur esthetic risks due to their color, especially in the esthetic zone. Currently, zirconia has been applied as an esthetic alternative material for implant abutments; however, zirconia is purported to be an inert biomaterial. How to improve the biological activities of zirconia has thus become a popular research topic. In this study, we presented a novel self-glazed zirconia (SZ) surface with nanotopography fabricated by additive 3D gel deposition and investigated its soft tissue integration capability compared to that of clinically used titanium and polished conventional zirconia surfaces.

Materials and Methods

Three groups of disc samples were prepared for in vitro study and the three groups of abutment samples were prepared for in vivo study. The surface topography, roughness, wettability and chemical composition of the samples were examined. Moreover, we analyzed the effect of the three groups of samples on protein adsorption and on the biological behavior of human gingival keratinocytes (HGKs) and human gingival fibroblasts (HGFs). Furthermore, we conducted an in vivo study in which the bilateral mandibular anterior teeth of rabbits were extracted and replaced with implants and corresponding abutments.

Results

The surface of SZ showed a unique nanotopography with nm range roughness and a greater ability to absorb protein. The promoted expression of adhesion molecules in both HGKs and HGFs was observed on the SZ surface compared to the surfaces of Ti and PCZ, while the cell viability and proliferation of HGKs and the number of HGFs adhesion were not significant among all groups. In vivo results showed that the SZ abutment formed strong biological sealing at the abutment-soft tissue interface and exhibited markedly more hemidesmosomes when observed with a transmission electron microscope.

Conclusion

These results demonstrated that the novel SZ surface with nanotopography promoted soft tissue integration, suggesting its promising application as a zirconia surface for the dental abutment.

Review on Biocompatibility and Prospect Biomedical Applications of Novel Functional Metallic Glasses

The continuous development of novel materials for biomedical applications is resulting in an increasingly better prognosis for patients. The application of more advanced materials relates to fewer complications and a desirable higher percentage of successful treatments. New, innovative materials being considered for biomedical applications are metallic alloys with an amorphous internal structure called metallic glasses. They are currently in a dynamic phase of development both in terms of formulating new chemical compositions and testing their properties in terms of intended biocompatibility. This review article intends to synthesize the latest research results in the field of biocompatible metallic glasses to create a more coherent picture of these materials. It summarizes and discusses the most recent findings in the areas of mechanical properties, corrosion resistance, in vitro cellular studies, antibacterial properties, and in vivo animal studies. Results are collected mainly for the most popular metallic glasses manufactured as thin films, coatings, and in bulk form. Considered materials include alloys based on zirconium and titanium, as well as new promising ones based on magnesium, tantalum, and palladium. From the properties of the examined metallic glasses, possible areas of application and further research directions to fill existing gaps are proposed.

Magnetron sputtering of strontium nanolayer on zirconia implant to enhance osteogenesis

The zirconia implants have a wide range of clinical applications, however, the biological inertness and lack of osteoinductive properties limit these applications. Strontium possesses superior biocompatibility and excellent osteogenic properties. To take advantage of these, the strontium titanate-coated zirconia implants were prepared in this study by sandblasting, acid etching, and magnetron sputtering, followed by the analysis of the biological behavior. Briefly, the zirconia sheets were polished and subjected to sandblasting and acid etching. Subsequently, a nano‑strontium titanate coating was developed on the sheets by magnetron sputtering. The specimens were characterized by scanning electron microscopy (SEM), water contact angle measurement (WCA) and EDS mapping, which confirmed the physical alternation and successful deposition of the strontium titanate coating. The in vitro experiments indicated that the majority of the filopodia and actin fibers of the MC3T3-E1 cells on SA-ZrO₂/Sr possessed an optimal osteogenic property to promote the osteogenic differentiation. Moreover, the RT-PCR results revealed that SA-ZrO₂/Sr significantly up-regulated the gene expression of Runx2, COL-1, ALP, OPG, OPN and OCN. Further, the in vivo evaluation confirmed that the SA-ZrO₂/Sr implants promoted the bone-implant osseointegration to the greatest extent as compared to SA-ZrO₂ and ZrO₂ implant. Overall, the SA-ZrO₂/Sr system was confirmed to be a promising implant, thus, providing new pathways for an effective implant design.