Evaluation of bonding to denture base and mechanical properties of soft realining materials

In this study, peel and shear bond strength of four different soft relining materials were evaluated. The mechanical properties of these materials were also evaluated with regard to tear and tensile strengths. Four soft relining materials, Molloplast B, Flexor CC, Mucopren soft and Ufigel soft were chosen. Heat polymerized Meliodent was used as the denture base material. Five samples for each material were prepared according to the standards for peel and shear bond; tear and tensile testing of soft relining materials. Tests were performed on a universal testing machine and data was collected by a PC using Nexygen software. In order to evaluate the effect of different bonding agents on the denture base material, SEM imaging technique was used. Each bonding agent was applied to the surface of denture base material and images were taken after the drying of the agent. In addition, SEM images were taken from the surfaces of failed specimens for the concern of understanding the nature of the failure whereas failure types were classified as adhesive or cohesive.-105 According to the results of this study, soft relining materials gave different results for bond strength tests. Mucopren soft material gave the highest results for peel bond strength testing setups whereas Molloplast, Flexor CC and Ufigel Soft materials were found to be in the same statistical group(p>0.05). Likewise, Mucopren soft material gave the highest results for shear bond testing and a significant difference was found with Flexor CC material (p<0.05). Failure types were classified as cohesive for Mucopren soft and Molloplast B materials and adhesive for the other mateiials used. During the mechanical testing of these materials, no significant difference (p>0.05) were found among materials with regard to tear strength. According to the results of tensile strength test, Molloplast B, Flexor CC and Mucopren soft were in the higher group(p>0.05) whereas lowest results were obtained from Ufigel soft. SEM imaging and observations showed that the recommended bonding agents affected the poly(methyl methacrylate) surface differently. The smoothest surface was observed with the bonding agent of Mucopren soft. The level of smoothness observed was Ufigel soft>Molloplast B>Flexor.