Advances in Zirconia Crowns: A Comprehensive Review of Strength, Aesthetics, Digital Manufacturing, and Clinical Performance

Abstract

The use of zirconia as a material in the base of modern restorative dentistry is due to its high strength, biocompatibility, and improved aesthetic performance. The aim of this review is to provide an integrated and coherent overview of the recent developments in zirconia crowns by focusing on the development of materials, microstructure, digital fabrication processes, optical capabilities, and clinical performance. A survey of literature in the form of a narrative literature review was conducted in the most significant databases, such as PubMed, Scopus, Web of Science, and Google Scholar, including publications published since 2000, with a focus on systematic reviews, meta-analyses, clinical studies, and materials science studies. The results show that zirconia materials have developed beyond traditional 3Y-TZP systems, characterized by high strength and fracture toughness to high-translucency and multilayer zirconia (4Y 6Y-PSZ) systems, which provide better aesthetics at the cost of lower mechanical reliability. The implementation of CAD/CAM technologies has enhanced the accuracy of fabrication, marginal fit and reproducibility and the development of sintering, surface modification and bonding protocols has enhanced clinical performance. Recent clinical results have shown high survival rates (around 85–95 percent over 5–10 years), and the results depend on the design of the restoration, the zirconia generation, and the functional loading circumstances. Despite these developments, there are still concerns about the durability of bonding, trade-offs between translucency and strength, and long-term performance of high-translucency zirconia. The development of new technologies, such as additive manufacturing, design-aided artificial intelligence, and bioactive surface modification, is a promising avenue toward improving clinical reliability and performance.