Effects of Sandblasting and Laser Irradiation on Shear Bond Strength of Low-fusing Porcelain to Titanium

Purpose: To investigate the bond strength of low-fusing porcelain to commercially pure titanium (Ti) that was laser irradiated with different levels of energy and sandblasted. Materials and Methods: A total of 30 titanium rods (10 mm in length and 12 mm in diameter) were prepared. The rods were divided into three groups (n = 10) according to surface treatments: SB: sandblasted; L1: Nd: YAG laser irradiated at 100 mJ, 10 Hz, and 1 W; L2: Nd: YAG laser irradiated at 200 mJ, 10 Hz, and 2 W. After surface treatment, low-fusing porcelain was applied onto the titanium specimens according to the manufacturer's instructions, and these specimens were stored in distilled water at 37 C for 24 h. The shear bond strength test was performed at a crosshead speed of 1 mm/min. In addition, Kruskal-Wallis and Mann-Whitney U-tests were used to compare the bond strength results (alpha = 0.05). SEM and EDS analysis were also performed for one specimen of each group after the shear bond strength test to evaluate the nature of the fracture surface. Results: Group L2 produced the highest shear bond strength among the groups. There was a statistically significant difference in shear bond strength between groups L1 and L2 (p < 0.001). Nevertheless, no significant difference was found between groups SB and L1. EDS analysis revealed that laser treatment reduced presence of oxygen on the surface of Ti. In contrast to the sandblasted specimens, laser-irradiated specimens showed predominantly adhesive failure. Conclusion: Laser treatment may be an alternative method to sandblasting for enhancing the bond strength of low-fusing porcelain to commercially pure titanium.