Evaluation of bonding methods on shear bond strength between cobalt-chromium and titanium alloys fabricated by selective laser melting and denture base resins

This study evaluated the shear bond strength (SBS) between cobalt-chromium (CoCr) and titanium (Ti) alloys fabricated via selective laser melting (SLM) and denture base resins with different bonding methods. After surface pretreatment of cylindrical CoCr and Ti alloy specimens, bonding was performed using three methods: the compression molding (CM) method, the pouring (PT) method, and the method using 4-META/MMA-TBB resin (SB). SBS tests were performed after storing all specimens in distilled water at 37ºC for 24 h, either immediately or following 10,000 thermocycles. For CoCr alloys, without thermocycling, the CM method exhibited significantly higher SBS than SB method (p<0.001), but no significant differences were observed with thermocycling. For Ti alloys, the CM method showed significantly higher SBS than the SB method without thermocycling (p=0.018) and was higher than the PT method with thermocycling (p=0.047). These results suggested the CM method may be a promising bonding technique for SLM-fabricated alloys.