Flexural and bonding properties of a denture base polymer treated with nitric acid or ultraviolet radiation before relining with Molloplast-b

This study investigated adhesive forces and flexural strength of acrylic resin denture base relined with Molloplast-B soft lining material. To increase bonding between the two materials, the surface of the resin was modified with ultraviolet (UV) irradiation or nitric acid treatment. The peel strength greatly increased with nitric acid treatment because of the high polarity on the poly (methyl methacrylate) (PMMA) surface and the increase in the surface roughness, whereas low peel strength was seen with the UV treatment of the PMMA surface. Although both types of the surface pretreatment increased the flexural strength of PMMA-reline composites compared with the control and bulk PMMA groups, the increase in the UV-treated group was found to be higher than that of the nitric acid treated group.