Federal University of Rio Grande do Norte (UFRN), Department of Dentistry, Av. Salgado Filho, 1787, Lagoa Nova, Natal, RN, CEP: 59056-000, Brazil.
Federal University of Rio Grande do Norte (UFRN), Department of Dentistry, Division of Prosthodontics, Av. Salgado Filho, 1787, Lagoa Nova, Natal, RN, 59056-000, Brazil.
Dent Mater. 2020 Apr;36(4):e126-e139. doi: 10.1016/j.dental.2020.01.004. Epub 2020 Jan 31.
To investigate the effect of different surface finishing and polishing regimes and low temperature degradation on flexural strength, phase transformation and surface topography of ultra-translucent ZrO ceramic.
300 (n=15/group) of conventional zirconia (Z: Ice Zirkon Transluzent) and ultra-translucent zirconia (UT: Prettau Anterior) bar-specimens were made and divided according to the "Finishing/Polishing" - (C - Control, B - diamond rubber polishers, P - adjusting with burs, PB - adjusting with burs+diamond polishers, PG - adjusting with burs+glaze), "Low temperature Degradation (LTD)" (with or without a treatment at 127°C, 1.7bar/24h). Then, a 3-point mini flexural test was performed in a universal testing machine (1mm/min, 500kgf load cell). SEM, EDS, XDR, AFM, optical profilometry and Weibull analysis were performed. Data were analyzed by 3-way ANOVA and Tukey's post-test (5%).
Groups ZPB (1670±253MPa), ZB (1664±217MPa), and ZB (1655±3678MPa) showed significantly higher flexural strength than the UTPG group (372±56MPa). The Weibull modulus was significantly higher for the ZP group compared to the UB, UC, UP and UPB, while UTB, UTC and UTP had the lowest value. Monoclinic phases were observed only in the conventional zirconia groups and were more evident after LTD. Diamond rubber polishers presented less roughness for both zirconias.
The use of diamond rubber polishers is the most suitable finishing/polishing method for zirconia ceramic restorations and that final glazing reduces the fracture resistance of these materials.
研究不同表面处理和抛光方案以及低温降解对超透氧化锆陶瓷的弯曲强度、相转变和表面形貌的影响。
制作了 300 个（n=15/组）常规氧化锆（Z：Ice Zirkon Transluzent）和超透氧化锆（UT：Prettau Anterior）棒试件，并根据“精整/抛光”（C-对照、B-金刚石橡胶抛光器、P-用磨具调整、PB-用磨具和金刚石抛光器调整、PG-用磨具和釉料调整）和“低温降解（LTD）”（是否在 127°C、1.7bar/24h 下处理）进行分组。然后，在万能试验机上进行三点微型弯曲试验（1mm/min，500kgf 载荷单元）。进行 SEM、EDS、XDR、AFM、光学轮廓仪和威布尔分析。采用三因素方差分析和 Tukey 事后检验（5%）对数据进行分析。
ZPB（1670±253MPa）、ZB（1664±217MPa）和 ZB（1655±3678MPa）组的弯曲强度明显高于 UTPG 组（372±56MPa）。与 UB、UC、UP 和 UPB 相比，ZP 组的威布尔模数明显较高，而 UTB、UTC 和 UTP 组的威布尔模数最低。只有常规氧化锆组观察到单斜相，且 LTD 后更为明显。金刚石橡胶抛光器对两种氧化锆的表面粗糙度都较低。
对于氧化锆陶瓷修复体，使用金刚石橡胶抛光器是最合适的精整/抛光方法，而最终上釉会降低这些材料的断裂强度。
