Evaluation of Bond Strength of Acrylic Denture Tooth to Heat Polymerized Denture Base Resin after Different Surface Treatments on the Bonding Surface of Acrylic Tooth: An In Vitro Study.

AIM: Debonding of acrylic denture tooth from the denture base resin is the most common failures in denture repair. The objectives of the study were (i) to evaluate and compare the bond strength of acrylic resin denture teeth to denture base resins after various surface treatments on the bonding area of acrylic denture teeth. (ii) to evaluate the type of failure (adhesive or cohesive) between the bonding surface of acrylic teeth and the denture base resin after these surface treatments. MATERIALS AND METHODS: 50 right and 50 left maxillary highly cross-linked acrylic central incisor denture teeth of same size and shade were selected. The 100 teeth were then divided into 5 groups. Group A served as control with no surface treatment. The other groups were B, C, D and E according to surface treatments with Heat-curing methylmethaacrylate Monomer, Acetone, Vitacoll bonding agent and Superbond bonding agent respectively. Wax models were made using a custom made jig such that the tooth was placed with a labial inclination of 1300 from the denture base and were invested and de-waxed. Surface agents were applied on the bonding surface of acrylic denture tooth. The specimens were packed with heat polymerizing denture base resin, then cured, finished and polished. After storing 1week in water for aging, the bond strengths of each group samples were evaluated using a Universal Testing Machine and values recorded. RESULTS: Bond strength values were subjected to statistical analysis using one way Anova, Tukey’s HSD and Chi- square tests. The Group E- Superbond surface treated samples had the highest bond strength values and all the failures recorded were cohesive in nature. Group C - Acetone surface treated samples had better bond strength values. There was no statistical difference in bond strength values of Group A - Control, Group B- Monomer and Group DVitacoll bonding agent groups. CONCLUSION: Surface treatment of the bonding surface of acrylic denture tooth before packing improved bonding with the denture base resin. Superbond- bonding agent samples had the highest mean bond strength values of all the tested samples with easy application protocol