The objective of this article was to explain the quality of zirconia ceramics and their benefits in dentistry. It has better mechanical properties as compared to other ceramic materials when used for all-ceramic posterior fixed partial dentures. The microstructures of zirconia ceramics in tetragonal phase can transform to monoclinic phase as temperature and stress changes. The effect of phase transformation or transformation toughening mechanisms enhances mechanical properties of zirconia ceramics which is suitable for clinical application in posterior fixed partial dentures. In addition, this article review the degradation of zirconia ceramics when exposed to water or other solutions for precaution in selecting zirconia ceramics for clinical uses.