Search Results (2)

Based on their high mechanical strength, Ti-based high-entropy alloys (HEAs) are of great potential as materials for high-performance reduced-diameter dental implants. Despite previous studies demonstrating their corrosion resistance in various simulated body fluids, their resistance in simulated buccal conditions has yet to be confirmed. In this work, the corrosion behavior of two Ti-based HEAs, TiZrHfNb, and TiZrHfNbTa was evaluated in comparison to CP-Ti and Ti-6Al-4V in artificial saliva (AS) solution and in AS with fluoride ion content (ASF). A set of electrochemical tests (electrochemical impedance spectroscopy, cyclic polarization, and Mott–Schottky) was employed and complemented with surface characterization analyses (scanning electron microscopy and atomic force microscopy) to determine dissolution and passivation mechanisms of the alloys. In general, the HEAs exhibited a far superior corrosion resistance compared to CP-Ti and Ti-6Al-4V alloys in both solutions. In the AS solution, the TiZrHfNb exhibited the highest polarization resistance and pitting potential, indicating a high corrosion resistance due to the formation of a robust passive layer. Whilst in the ASF solution, the TiZrHfNbTa showed a greater corrosion resistance due to the synergistic effect of Nb and Ta oxides that enhanced passive film stability. This finding emphasizes the role of Ta in elevating the corrosion resistance of Ti-based HEAs in the presence of fluoride ions and confirms the importance of chemical composition optimization in the development of next-generation dental alloys. Based on its electrochemical corrosion behavior, TiZrHfNbTa HEAs are promising new materials for high-performance reduced-diameter dental implants. Full article

Amidst the prevalence of aggressive bacterial infections that can impact both oral and systemic health following various dental and implant procedures, the search for alternative, high-performing and biocompatible materials has become a challenging pursuit. The need for such investigations is increasing owing to the fact that toxicological risks of cobalt–chromium (CoCr) alloys used in dentistry have become a part of the EU’s new Medical Devices Regulations establishing that cobalt metal has been classified as carcinogenic, genotoxic and detrimental to reproduction. Within this context, this review proposes high entropy alloys (HEA) as potential alternatives and presents their characteristics and in vitro biological performance when used as a substrate or coating. Anatomical details of the oral cavity in relationship with prosthodontics and implant dentistry support the paper’s motivation and presentation. The review highlights the innovative manufacturing procedures, microstructure and properties of both the bulk and coatings of BioHEA. It evaluates the performance of BioHEAs based on their complete characterization and assesses their suitability for novel applications in dentistry, serving as the primary objective of this manuscript. Full article