RSUSSH 2020
IN20-057 The Effect of Different Surface Treatments on Tensile Bond Strength of Acrylic Denture Teeth and Light-cured Resin composite
Presenter: Chotinut Wongpornpirot
Chulalongkorn University, Thailand
Abstract
Acrylic denture teeth often exhibit wear or fracture which may lead to a loss of mastication efficiency and aesthetically unpleasant. Light-cured resin composite can be used to repair the acrylic denture teeth. However, the research published on the tensile bond strength between acrylic denture teeth and resin composite is very limited. The purpose of this study is to investigate the effect of different chemical surface treatments on tensile bond strength of acrylic denture teeth and resin composite. Sixty maxillary lateral incisors acrylic denture teeth were embedded with labial surface downwards and ground with silicon carbide paper. The teeth were divided into six groups (n=10): no surface treatment (control), methyl methacrylate treatment (MMA) for 180 seconds, methyl formate-methyl acetate mixture (MF-MA) solution at a ratio of 25:75 (v/v) treatment for 15 seconds, composite bonding agents, MMA (180 seconds) with the application of bonding agent, and MF-MA (15 seconds) with a bonding agent. Tensile strength was measured using a universal testing machine at crosshead speed 0.5mm/min. The data were analyzed using one-way ANOVA and post hoc Dunnett T3 test (α=0.05). The surface treatments significantly affected the tensile bond strength between acrylic denture teeth and resin composite (p<0.05). The bond strengths of the control group, MMA treated, and MF-MA treated group were not significantly different (p>0.05). The bond strength of the MF-MA with bonding agent group was significantly higher than the other group (p<0.05). This study suggests the application of MF-MA solution for 15 s followed by a composite bonding agent before repair procedure can increase the tensile bond strength between acrylic denture teeth and resin composite.
Citation format:
Wongpornpirot, C., & Wiwatwarrapan, C.. (2020). The Effect of Different Surface Treatments on Tensile Bond Strength of Acrylic Denture Teeth and Light-cured Resin composite. Proceeding in RSU International Research Conference, May 1, 2020. Pathum Thani, Thailand.QUESTIONS & ANSWERS
Thank you for the interesting experiment. In this study, the uncured resin composite was used to repair the denture, and you discussed that the bonding agent improves wetteability and penetration of resin composite. What do you think or do you have any discussion if the cured resin composite teeth was used to repair the denture.
thank you very much
Dear Dr.Spun Lenglerdphol,
Thank you for your question,
According to Bartoloni et al. (Bartoloni, Murchison, Wofford, & Sarkar, 2000) and Urban et al. (Urban et al., 2007), heat-cured polymethyl methacrylate is highly polymerized, the degree of conversion is approximately 93%, therefore the chemical bond between the acrylic denture teeth and the repaired materials may not occur. In order to achieve effective mechanical retention, chemical solvents that have similar solubility parameters to the solubility parameter of polymethyl methacrylate must be used to swell the denture teeth surface and create the micro-irregularities. Moreover, the materials that are used to repair denture teeth must be small and have low viscosity enough to penetrate and infiltrate into the microstructure which will resulted in micro-mechanical retention.
Using a bonding agent not only improves the wettability of resin composite but the monomers present in bonding agent that are similar to those used in resin composite also play an important role in the polymerization between the bonding agent and the newly applied resin composite. Therefore, using the cured resin composite teeth to repair the denture may not provide sufficient bond strength, since the consistency of the cure resin composite teeth are high and resin composite teeth do not contain the monomers to polymerize with the bonding agent.
Your respectfully, Chotinut Wongpornpirot