| Popis: |
The main disadvantage of conventional zirconia is its high opacity. Depending on different conditions, especially the content of the yttrium stabilizer, it is possible to circumvent this issue, in view of this, several generations of yttrium stabilized zirconia were developed seeking to combine the robustness of zirconia with the aesthetics of porcelain veneers. The present work aimed to carry out an analysis on how the increase or decrease in the percentage of yttrium in the composition of monolithic zirconia can influence their properties, especially with regard to translucency. This study was carried out through a review in the Scielo, PubMed and Google Scholar databases with articles published between 2008 and 2021. In this way, it was concluded that the higher content of Y2O3 tended to increase the amount of isotropic cubic phase present and reduce the amount of birefringent tetragonal phase in ZrO2 together with a minimization of light scattering by secondary phases, leading to increased translucency and aging resistance. As yttrium oxide increases, zirconia grain sizes tend to increase as well, and translucency may improve with increasing grain size. Toughness and fracture toughness can be sacrificed considerably. |
