Repair of denture base resins with visible light-polymerized reline material: Effect on tensile and shear bond strengths

Statement of problem. Triad visible light-polymerized (VLP) reline resin has the potential to repair denture bases from other resin systems with the elimination of flasking/deflasking procedures. Purpose. This study measured the tensile and shear bond strengths of Triad VLP, PMMA,, and glass-fiber-reinforced PMMA (GF-PMMA) acrylic resins before and after repair with Triad VLP reline material. Material and methods. Fifty-six specimens were fabricated from Triad NTP, PMMA, and GF-PMMA denture base resins. Both Triad VLP reline material and autopolymerizing acrylic resins were used to repair identical laboratory fabricated resin joints. Twenty-eight rectangular specimens (in 4 different groups of 7 each) were prepared to study the shear bond strength of Triad reline material used to repair different denture base resin joints. Results. Statistically significant differences (P < .0001) were found between the tensile strengths of specimens repaired with the Triad VLP reline resin used as a repair agent and those repaired with the autopolymerizing resin. The tensile strength of the Triad NTP denture base resin was found to be higher than that of both the PMMA, and GF-PMMA acrylic resins. Conclusion. The low tensile and shear bond strengths found after the repair of PMMA and GF-PMMA acrylic resins,vith Triad VLP reline material were attributed to a lack of cohesion/adhesion between the Triad VLP reline material and the interfaces of the treated sites. The use of Triad VLP reline material to repair Triad VLP denture base resin produced the highest strengths.