Shear bond strength of visible-light-cured resin relative to heat-cured resin

One promising clinical application of visible-light-cured (VLC) denture resin is for relining complete and partial dentures. Typically, a VLC resin would be used to reline an existing prosthesis fabricated from heat-cured resin (HCR). This study measured the shear bond strength of a VLC resin bonded to HCR specimens by different bonding agents. For comparison, we measured the shear bond strengths of VLC resin bonded to VLC resin specimens and of autopolymerizing resin (APR) to HCR specimens. Cylindrical specimens of HCR (n = 126) and VLC (n = 24) were thermocycled to simulate aging, and the bonding surfaces were prepared by being sanded to approximate clinical roughness. The specimens were divided into seven groups of approximately 20 each, and test materials were bonded by different bonding agents. Statistical analysis by ANOVA and the Student-Newman-Keuls test showed significant differences (p less than 0.05) among all groups except APR to HCR/no bonding agent, VLC to HCR/VLC bonding agent, or VLC to HCR/VLC and HCR bonding agent. The traditional bond of APR to HCR with HCR bonding agent was significantly stronger (p less than 0.05) than the strongest bond of VLC to HCR with HCR and VLC bonding agents.