Zirconia in dental prosthetics: a literature review

A large portion of the global human population carries a type of medical implant. Dental implants are an important part of this category, and the crowns they support are vital for satisfying the patients' needs both functionally and aesthetically. Materials science pertaining to dental crowns is a driver of their development, and currently zirconium oxide (zirconia) is a promising non-metal alternative, exhibiting biocompatibility and excellent mechanical and aesthetic properties. This review aims to collate a selection of the extensive testing and research that has been performed and evaluated on a variety of zirconia-based ceramics, as there are many commercial brands developing blank and powdered samples for refinement into structurally sound dental prosthetics. Significant advancements regarding manufacturing technologies for zirconia-based ceramics are also currently in progress. Methodologies and conditions for uniaxial and isostatic pressing of zirconia powder are reviewed, as are the benefits of emerging CAD/CAM technologies. Several knowledge gaps were identified based on this review, primarily that different sintering conditions and methodologies, such as two-step sintering, should be investigated experimentally. Preliminary studies using alternative methods show promising results, and further trialling would help to ensure that the mechanical, aesthetic and ageing properties of the final product are enhanced and optimised. (C) 2019 The Authors. Published by Elsevier B.V.