Effect of Reinforcement of Aluminium Oxide Nano Particles on Flexural Strength of Different Mechanical Configurations of Heat Cure and Micro- Wave Repaired Samples before and After Thermocycling

Abstract

Aim: To evaluate and compare flexural strength of different mechanical configurations of heat cure and micro-wave repaired samples with and without reinforcement of aluminum oxide nano particles before and after thermocycling. Materaials & Methodology: A total of 160 samples with four different mechanical configurations; repaired with and without reinforcement of repair material; have been prepared using heat cure and microwave processing methods and stored in distilled water. 80 samples (i.e 10 samples from each configuration) have been subjected to thermo cycling and evaluated for flexural strength; remaining 80 samples remained as control group and were evaluated for flexural strength without thermo cycling. All the results were subjected to statistical analysis (“student t-test” and Anova) and were compared.

Results: Among the Percentage declination of flexural strength values of sample groups of all configurations repaired by heat and microwave cured methods without nano alumina reinforcement of repair material, before and after thermocycling;Microwave repaired 45⁰ bevel joint configuration has shown highest percentage declination ( -12.67) , and microwave cured repaired butt joint configuration has shown flexural strength increase by (6.97%). Similarly, the Percentage declination of flexural strength values of sample groups of all configurations repaired by heat and microwave cured methods with nano alumina reinforcement of repair material, before and after thermocycling; microwave repaired 45⁰ bevel joint configuration has shown highest percentage declination ( -11.42), and heat cured repaired butt joint configuration has shown flexural strength increase by (4.89%).

Conclusion: Within the limitations of this study, among all the mechanical configurations; round end joint has shown highest flexural strength with and without reinforcement in both heat cure and microwave processed samples. Microwave processed samples in all the configurations with and without reinforcement of nano alumina have shown higher flexural strength values than heat cure samples. All the samples which are evaluated without thermocycling has shown higher flexural strength values than samples which are subjected to thermocycling in both with and without reinforcement of nano alumina except in butt joint configurations.