Optical and Mechanical Properties of Monolithic Zirconia Y-TZP: Systematic Review

Objectives: This study reviewed and evaluated existing research and publications about the influences that modifications have on Monolithic Y-TZP Zirconia to improve the optical properties that it confers, without reducing its mechanical properties.
Methods: A structured PICO question was developed, where (P) stood for Yttria partially stabilized polycrystalline tetragonal zirconia Y-TZP, (I): evaluation of the optical and mechanical properties of zirconia Y-TZP, (C): glass ceramics and resin matrix ceramics (layered zirconia), (O): optical and mechanical properties of the zirconia Y-ZTP. An electronic search was carried out in the databases: Pubmed, Cochrane, Scielo, LILACS, EBSCO, BMC, Trip Database, and Epistemonikos, from January, 2005 to July, 2021, using the key terms and their combinations: “Ytrria stabilized tetragonal zirconia, Yttria stabilized zirconia AND optical phenomena, Yttria stabilized tetragonal zirconia AND optical phenomena NOT dental implants, and lastly the combination of Yttria stabilized tetragonal zirconia AND optical phenomena And mechanical Phenomena”.
Results: From the total of 1367 articles, 1001 were eliminated for having duplicate titles, resulting in 366 articles, of these 304 were eliminated for not including information associated with the research question in their title, later 62 articles were subject to revision of the introduction, eliminating a total of 45, for not having information according to the topic, 17 articles were used for full reading and analysis between authors. Twelve studies met the eligibility criteria.
Conclusions: Based on the findings, it was detected that most of the studies are experimental and in vitro, however, very few show the long-term behavior of the material. Therefore, the following conclusions are drawn: most authors agree that zirconia has good optical and mechanical properties and while its optical properties increase, mechanical resistance decrease proportionally. However, these findings must be interpreted with caution given the limitations of the study.