Preparation of graded zirconia–CaP composite and studies of its effects on rat osteoblast cells in vitro

Load, unload and repeat: Understanding the mechanical characteristics of zirconia in dentistry

OBJECTIVES

Zirconia-based dental restorations and implants are gaining attention due to their bioactivity, corrosion resistance and mechanical stability. Further, surface modification of zirconia implants has been performed at the macro-, micro- and nanoscale to augment bioactivity. While zirconia's physical and chemical characteristics have been documented, its relation to mechanical performance still needs to be explored. This extensive review aims to address this knowledge gap.

METHODS

This review critically compares and contrasts the findings from articles published in the domain of 'mechanical stability of zirconia\ in dentistry' based on a literature survey (Web of Science, Medline/PubMed and Scopus databases) and a review of the relevant publications in international peer-reviewed journals. Reviewing the published data, the mechanical properties of zirconia, such as fracture resistance, stress/tension, flexural strength, fatigue, and wear are detailed and discussed to understand the biomechanical compatibility of zirconia with the mechanical performance of modified zirconia in dentistry also explored.

RESULTS

A comprehensive insight into dental zirconia's critical fundamental mechanical characteristics and performance is presented. Further, research challenges and future directions in this domain are recommended.

SIGNIFICANCE

This review extends existing knowledge of zirconia's biomechanical performance and it they can be modulated to design the next generation of zirconia dental restorations and implants to withstand long-term constant loading.

Advancing dental implants: Bioactive and therapeutic modifications of zirconia

Zirconium-based implants have gained popularity in the dental implant field owing to their corrosion resistance and biocompatibility, attributed to the formation of a native zirconia (ZrO₂) film. However, enhanced bioactivity and local therapy from such implants are desirable to enable the earlier establishment and improved long-term maintenance of implant integration, especially in compromised patient conditions. As a result, surface modification of zirconium-based implants have been performed using various physical, chemical and biological techniques at the macro-, micro-, and nano-scales. In this extensive review, we discuss and detail the development of Zr implants covering the spectrum from past and present advancements to future perspectives, arriving at the next generation of highly bioactive and therapeutic nano-engineered Zr-based implants. The review provides in-depth knowledge of the bioactive/therapeutic value of surface modification of Zr implants in dental implant applications focusing on clinical translation.

Towards Clinical Translation: Optimized Fabrication of Controlled Nanostructures on Implant-Relevant Curved Zirconium Surfaces

Anodization enables fabrication of controlled nanotopographies on Ti implants to offer tailorable bioactivity and local therapy. However, anodization of Zr implants to fabricate ZrO₂ nanostructures remains underexplored and are limited to the modification of easy-to-manage flat Zr foils, which do not represent the shape of clinically used implants. In this pioneering study, we report extensive optimization of various nanostructures on implant-relevant micro-rough Zr curved surfaces, bringing this technology closer to clinical translation. Further, we explore the use of sonication to remove the top nanoporous layer to reveal the underlying nanotubes. Nano-engineered Zr surfaces can be applied towards enhancing the bioactivity and therapeutic potential of conventional Zr-based implants.

Preparation and characterization of biomedical highly porous Ti-Nb alloy

The compressive strength and the biocompatibility were assessed for the porous Ti-25 wt%Nb alloy fabricated by the combination of the sponge impregnation technique and sintering technique. The alloy provided pore sizes of 300-600 μm, porosity levels of 71 ± 1.5%, in which the volume fraction of open pores was 94 ± 1.3%. The measurements also showed that the alloy had the compressive Young's modulus of 2.23 ± 0.5 GPa and the strength of 98.4 ± 4.5 MPa, indicating that the mechanical properties of the alloy are similar to those of human bone. The scanning electron microscopy (SEM) observations revealed that the pores were well connected to form three-dimension (3D) network open cell structure. Moreover, no obvious impurities were detected in the porous structure. The experiments also confirmed that rabbit bone mesenchymal stem cells (MSCs) could adhere and proliferate in the porous Ti-25 wt%Nb alloy. The interactions between the porous alloy and the cells are attributed to the porous structure with relatively higher surface. The suitable mechanical and biocompatible properties confirmed that this material has a promising potential in the application for tissue engineering.

Smart rose flower like bioceramic/metal oxide dual layer coating with enhanced anti-bacterial, anti-cancer, anti-corrosive and biocompatible properties for improved orthopedic applications

The flower like Se,Mn-HAP/ZrO2 dual layer coating on AZ91 magnesium alloy satisfies the requirements in bone cancer treatment and signifies progress in the field of implant materials.

Laser pulse dependent micro textured calcium phosphate coatings for improved wettability and cell compatibility

Surface wettability of an implant material is an important criterion in biological response as it controls the adsorption of proteins followed by attachment of cells to its surface. Hence, micro-textured calcium phosphate coatings with four length scales were synthesized on Ti-6Al-4V substrates by a laser cladding technique and their effects on wettability and cell adhesion were systematically evaluated. Microstructure and morphological evolutions of the coatings were studied using scanning electron and light optical microscopes respectively. The surface texture of coating defined in terms of a texture parameter was correlated to its wetting behavior. The contact angle of simulated body fluid measured by a static sessile drop technique, demonstrated an increased hydrophilicity with decreasing value of texture parameter. The influence of such textures on the in vitro bioactivity and in vitro biocompatibility were studied by the immersion of the samples in simulated body fluid and mouse MC3T3-E1 osteoblast-like cell culture respectively.