Comparison of the Flexural Strength and Surface Roughness of Conventional Heat Cure and High Impact Denture Base Resins on Microadditions of Carbon Nanotubes- An In Vitro Study

Background and Objectives: Midline fracture of dentures and fractures due to sudden impact on denture bases, like accidental dropping, are common. The limitation that the strength of these materials displays sets a need for further improvement of the polymethylmethacrylate resin. Studies have demonstrated that carbon nanotubes possess outstanding mechanical properties of flexural and impact strengths. The present study evaluated and compared the flexural strength and surface roughness on reinforcing conventional heat cure denture base resins and high impact resins with carbon nanotubes. Method: A metal template of specific dimensions 65 mm × 10 mm × 3 mm was fabricated and flasked to obtain moulds. Monomer (methylmethacrylate) containing 1wt% carbon nanotubes was mixed with DPI and Lucitone polymers respectively and packed into the moulds to obtain 20 samples for each. Monomer without nanoparticles was used to fabricate 20 more samples for each resin. Following curing and deflasking, a total of 80 specimens were finished to required dimensions. Surface roughness of each specimen was evaluated using an optical profilometer. The flexural strengths were evaluated using a Universal Testing Machine. Results: The results showed that there was statistically significant difference among the flexural strength values of the groups with microadditions of CNTs when compared to the groups without microadditions. The surface roughness values, on comparison, showed no statistical significance. Interpretation and Conclusion: On comparison of the values obtained, the study concludes that flexural strength significantly improved on addition of carbon nanotubes. However, the comparison of surface roughness values suggested that incorporation of nanotubes does not increase the surface roughness of denture resins.