Metallization by Sputtering to Improve the Bond Strength between Zirconia Ceramics and Resin Cements

Zirconia has been used as a prosthesis material for over a decade because of its excellent mechanical properties and esthetics. The surface treatment for zirconia generally involves sandblasting and the application of primers for favorable bond strength between the surface and resin. However, sandblasting causes the microcracking and chipping of the zirconia surface. To overcome these challenges, the metallization of the zirconia surface was performed. Ti and Au were sputtered on yttria stabilized zirconia (YSZ) disks and heated to 800 °C for 15 min in air. These disks were bonded to stainless-steel rods using resin cement. Then, shear bond strength tests were performed using an Instron-type testing machine. The shear bond strength of the Ti sputtering group was significantly higher than that of the other groups. According to the results of X-ray photoelectron spectroscopy and electron probe microanalysis, the Ti-sputtered YSZ surface contained both sub-titanium oxide and titanium oxide before heating. Sub-titanium oxide was converted to titanium oxide by heating. These results suggest that metallization using Ti is effective for zirconia surface treatment to improve the shear bond strength between YSZ and resin cement. This metallization technique for YSZ has potential in clinical applications

Effect of Silicon Carbide Fiber Length on the Flexural Strength and Flexural Modulus of Short Silicon Carbide Fiber-Reinforced Resin

Silicon carbide fibers have superior flexural properties and chemical stability compared to glass fibers. We investigated the flexural strength and modulus of an experimental, short silicon carbide fiber-reinforced resin. Short silicon carbide fibers with lengths of ~0.5, 1, 2, and 3 mm were prepared and silanized. Urethane dimethacrylate and triethylene glycol dimethacrylate were mixed at a 70:30 wt% ratio and used as the matrix resins. Each length of short silicon carbide fibers and the matrix resin were combined using a mixing machine and then used for specimen preparation. The three-point bending test conditions were in accordance with ISO 4049:2009. The fracture surfaces of the specimens after the three-point bending test were observed using secondary electron images. The data were statistically analyzed with a one-way analysis of variance and Tukey’s HSD test (α = 0.05). The flexural strength and modulus of the specimens containing 2 mm or 3 mm silicon carbide fibers were significantly higher than the other specimens. The river pattern was observed more clearly in specimens containing shorter silicon carbide fibers, although this pattern was observed in all specimens

Metallization by Sputtering to Improve the Bond Strength between Zirconia Ceramics and Resin Cements

Zirconia has been used as a prosthesis material for over a decade because of its excellent mechanical properties and esthetics. The surface treatment for zirconia generally involves sandblasting and the application of primers for favorable bond strength between the surface and resin. However, sandblasting causes the microcracking and chipping of the zirconia surface. To overcome these challenges, the metallization of the zirconia surface was performed. Ti and Au were sputtered on yttria stabilized zirconia (YSZ) disks and heated to 800 °C for 15 min in air. These disks were bonded to stainless-steel rods using resin cement. Then, shear bond strength tests were performed using an Instron-type testing machine. The shear bond strength of the Ti sputtering group was significantly higher than that of the other groups. According to the results of X-ray photoelectron spectroscopy and electron probe microanalysis, the Ti-sputtered YSZ surface contained both sub-titanium oxide and titanium oxide before heating. Sub-titanium oxide was converted to titanium oxide by heating. These results suggest that metallization using Ti is effective for zirconia surface treatment to improve the shear bond strength between YSZ and resin cement. This metallization technique for YSZ has potential in clinical applications