Source:Dental Materials
Author(s): Masanao Inokoshi, Haruki Shimizu, Kosuke Nozaki, Tomohiro Takagaki, Kumiko Yoshihara, Noriyuki Nagaoka, Fei Zhang, Jozef Vleugels, Bart Van Meerbeek, Shunsuke Minakuchi
ObjectiveTo assess the influence of alumina sandblasting on four highly translucent dental zirconia grades.MethodsFully sintered zirconia disk-shaped specimens (15-mm diameter; 0.5-mm thickness) of four highly translucent yttria partially stabilized zirconia (Y-PSZ) grades (KATANA HT, KATANA STML, KATANA UTML, Kuraray Noritake; Zpex Smile, Tosoh) were sandblasted with 50-μm alumina (Al2O3) sand (Kulzer) or left 'as-sintered' (control) (n=5). For each zirconia grade, the translucency was measured using a colorimeter. Surface roughness was assessed using 3D confocal laser microscopy, upon which the zirconia grades were statistically compared for surface roughness using a Kruskal–Wallis test (n=10). X-ray diffraction (XRD) with Rietveld analysis was used to assess the zirconia-phase composition. Micro-Raman spectroscopy was used to assess the potentially induced residual stress.ResultsThe translucency of KATANA UTML was the highest (36.7±1.8), whereas that of KATANA HT was the lowest (29.5±0.9). The 'Al2O3-sandblasted' and 'as-sintered' zirconia revealed comparable surface-roughness Sa values. Regarding zirconia-phase composition, XRD with Rietveld analysis revealed that the 'as-sintered' KATANA UTML contained the highest amount of cubic zirconia (c-ZrO2) phase (71wt%), while KATANA HT had the lowest amount of c-ZrO2 phase (41wt%). KATANA STML and Zpex Smile had a comparable zirconia-phase composition (60wt% c-ZrO2 phase). After Al2O3-sandblasting, a significant amount (over 25wt%) of rhombohedral zirconia (r-ZrO2) phase was detected for all highly translucent zirconia grades.SignificanceAl2O3-sandblasting did not affect the surface roughness of the three highly translucent Y-PSZ zirconia grades, but it changed its phase composition.
http://ift.tt/2CL6GdK
Δεν υπάρχουν σχόλια:
Δημοσίευση σχολίου