YTZP

YTZP stands for yttria-stabilized tetragonal zirconia polycrystal, a ceramic material in which zirconia (ZrO2) is stabilized with yttria (Y2O3). The yttria dopant maintains a metastable tetragonal phase at room temperature, enabling a stress-induced tetragonal-to-monoclinic transformation that produces transformation toughening and enhances fracture resistance.

The material is known for a combination of high strength, high fracture toughness, and good wear resistance, along with biocompatibility. It is relatively hard and durable, making it suitable for demanding wear applications while remaining compatible with biological tissues in dental and some biomedical contexts.

Manufacturing and processing typically involve powder synthesis, stabilization, and sintering to achieve full density. In dentistry, Y-TZP is commonly milled from pre-sintered CAD/CAM blocks and then fully sintered to achieve final density. It is available in different translucency grades; higher translucency is achieved by increasing the cubic phase content, which can reduce mechanical strength somewhat.

Applications are concentrated in dentistry, where Y-TZP is used for monolithic crowns and fixed dental prostheses, implant abutments, and other restorations requiring high strength and acceptable esthetics. Outside dentistry, yttria-stabilized zirconia polycrystals are employed in engineering ceramics and some biomedical implants that benefit from metal-free, high-strength alternatives.

Limitations and aging are considerations: Y-TZP can undergo low-temperature degradation in moist environments, leading to surface roughening and potential strength loss over time. Aging is mitigated through controlled grain size, optimized sintering, and careful material design, and it is common to avoid layering porcelains on Y-TZP to reduce veneer chipping.