IADR Abstract Archives
Sandblasting Increases the Flexural Strength of Highly Translucent Zirconia
Objectives: To assess the influence of alumina sandblasting on the flexural strength of four highly translucent dental zirconia grades.
Methods: Fully sintered zirconia disk-shaped specimens (14.5-mm diameter; 1.2-mm thickness) of four yttria partially stabilized (Y-PSZ) highly translucent zirconia grades (KATANA HT, KATANA STML, KATANA UTML, all Kuraray Noritake; Zpex Smile, Tosoh) were sandblasted with 50-µm alumina (Al2O3) sand (Kulzer) or left ‘as-sintered’ (control) (n=10). For each zirconia grade, the 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. X-ray diffraction (XRD) with Rietveld analysis was used to assess the zirconia-phase composition. Micro-Raman spectroscopy (µRaman) was used to assess the potentially induced residual stresses. The biaxial flexural strength was measured using a universal material-testing machine, followed by Weibull analysis.
Results: The ‘Al2O3-sandblasted’ zirconia resulted in significantly higher Sa values than the ‘as-sintered’ zirconia. XRD with Rietveld analysis revealed that the ‘Al2O3-sandblasted’ KATANA HT contained monoclinic zirconia (m-ZrO2) phase (5.8 wt%). µRaman revealed the presence of residual compressive stresses on the sandblasted surface of all zirconia grades. Weibull analysis revealed that Al2O3-sandblasting decreased the Weibull modulus of three highly translucent zirconia grades (KATANA HT, KATANA STML and Zpex Smile) and resulted in a significantly higher characteristic strength for KATANA HT and Zpex Smile. Al2O3-sandblasting slightly increased the Weibull characteristic strength of KATANA STML and KATANA UTML.
Conclusions: ‘Al2O3-sandblasted’ surfaces have a higher surface roughness and higher compressive stress than the ‘as sintered’ surface for all highly translucent zirconia grades. Al2O3-sandblasting increased flexural strength but decreased the Weibull modulus.
Methods: Fully sintered zirconia disk-shaped specimens (14.5-mm diameter; 1.2-mm thickness) of four yttria partially stabilized (Y-PSZ) highly translucent zirconia grades (KATANA HT, KATANA STML, KATANA UTML, all Kuraray Noritake; Zpex Smile, Tosoh) were sandblasted with 50-µm alumina (Al2O3) sand (Kulzer) or left ‘as-sintered’ (control) (n=10). For each zirconia grade, the 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. X-ray diffraction (XRD) with Rietveld analysis was used to assess the zirconia-phase composition. Micro-Raman spectroscopy (µRaman) was used to assess the potentially induced residual stresses. The biaxial flexural strength was measured using a universal material-testing machine, followed by Weibull analysis.
Results: The ‘Al2O3-sandblasted’ zirconia resulted in significantly higher Sa values than the ‘as-sintered’ zirconia. XRD with Rietveld analysis revealed that the ‘Al2O3-sandblasted’ KATANA HT contained monoclinic zirconia (m-ZrO2) phase (5.8 wt%). µRaman revealed the presence of residual compressive stresses on the sandblasted surface of all zirconia grades. Weibull analysis revealed that Al2O3-sandblasting decreased the Weibull modulus of three highly translucent zirconia grades (KATANA HT, KATANA STML and Zpex Smile) and resulted in a significantly higher characteristic strength for KATANA HT and Zpex Smile. Al2O3-sandblasting slightly increased the Weibull characteristic strength of KATANA STML and KATANA UTML.
Conclusions: ‘Al2O3-sandblasted’ surfaces have a higher surface roughness and higher compressive stress than the ‘as sintered’ surface for all highly translucent zirconia grades. Al2O3-sandblasting increased flexural strength but decreased the Weibull modulus.