Effects of surface treatment methods on shear bond strength of ceramic to cast, milled and laser-sintered titanium frameworks

Abstract

Aims: This study determined the effect of three different surface treatment methods [sandblasting (SB), tribochemical silica coating (TSC), and ytterbium fiber laser (YFL) roughening] on surface roughness and titanium-ceramic shear bond strength using specimens obtained using casting (CST), milling (ML) and selective laser melting (SLM). Methods:In this in vitro study, we obtained 32 cylindrical titanium specimens for each fabrication method and subjected them to each surface treatment method. Nine experiments (n=11) were conducted. One specimen was randomly selected from each group for scanning electron microscope analysis. Surface roughness was examined using a profilometer device (n=10). Ceramic was applied to titanium specimens. A universal testing machine was used to determine shear bond strength in megapascal (MPa).Results: Surface roughness of CST/YFL (1.254±0.058 µm), SLM/SB (1.294±0.054 µm), and SLM/ YFL (1.208±0.057 µm) groups were significantly higher than other groups (CST/SB, CST/TSC, ML/SB, ML/TSC, ML/YFL, and SLM/TSC, p<0.01). Shear bond strengths of CST/YFL (20.28±6.97 MPa), SLM/SB (21.9±8.06 MPa), and SLM/YFL (29.92±5.67 MPa) were significantly lower than other groups (p<0.01). Shear bond strength of the ML/SB group (42.40±7.52 MPa) was highest but there were no significant differences between ML/SB and CST/SB (33.04±7.62, p=0.101), CST/TSC (35.38±4.15, p=0.426), ML/TSC (40.03±6.42, p=0.998), ML/YFL (39.43±9.24, p=0.991) and SLM/TSC (37.05±7.84, p=0.766). Conclusions:This study showed that the production and surface treatment method impact shear bond strength. Excessive roughness affects the bonding strength. The highest shear bond strength was identified in the ML group.