ABSTRACT
To evaluate the characteristics of a thermomechanically loaded composite resin enhanced with graphene nanoparticles. A total of 60 specimens were manufactured with Test group TG1 (20), TG2 (20), and control group CG (20). All samples were subjected to surface roughness using a three-dimensional (3D) Optical profilometer and flexural strength. All specimens were subjected to thermomechanical cyclic loading. Microhardness measurement was performed with a microhardness tester. The average microhardness and flexural strength were higher in test groups TG1 and TG2 and lowest in control group CG. There was an improvement in surface roughness, flexural strength, and microhardness in the test group after the addition of graphene nanoparticles compared to the control group. Conclusion: The addition of graphene nanoparticles to composite resin significantly improved flexural strength and microhardness. The physical and chemical properties of the composite showed marked improvement.
ABSTRACT
OBJECTIVES: The successful endodontic therapy is judged by ability of tooth to withstand masticatory forces. The present study focused on comparing the strength of restorative materials, i.e., compomer, ormocer, nanocomposite, and ACTIVA Bioactive after conditioning in dietary solvents. MATERIALS AND METHODS: This in vitro study consisted of 26 specimens of each restorative material Compomer (F2000 3M ESPE), Nanocomposite (Filtek Z350XT), Ormocer (Admira VOCO), and ACTIVA Bioactive (Pulpdent). The I-shear-punch test was conducted with the help of custom-designed shear-punch apparatus in Universal Testing Machine in different dietary solvents. Results were statistically analyzed using IBM SPSS Statistics for Windows, Version 20.0. (IBM Corp., Armonk, NY) and using Tukey's test and one-way analysis of variance test at P < 0.5. RESULTS: Ormocer conditioned in heptanes had the highest mean shear-punch strength. ACTIVA Bioactive conditioned in distilled water showed the highest mean shear-punch strength. There was a significant difference in bond strength among all restorative materials (P < 0.05). CONCLUSION: Ormocer conditioned in heptane had significantly higher shear strength. ACTIVA Bioactive conditioned in distilled water had significantly increased shear strength. The nanofilled composite was significantly stronger than the Ormocer, ACTIVA Bioactive, and Compomer - a polyacid-modified composite.
