Effect of incorporating aluminum oxide nanoparticles on thermal conduction and flexural strength of acrylic resins

Abstract

Background: The mechanical and thermal properties of polymethyl methacrylate, as the most
commonly used material for the fabrication of dental prostheses, should be improved due to its structural
weaknesses. The present study aimed to compare the flexural strength and thermal conduction of two
heat‑cured and self‑cured acrylic resins reinforced with aluminum oxide nanoparticles.
Materials and Methods: In this in vitro study, a total of 114 samples consisting of heat‑ and
self‑cured three subgroups (1% and 3% Al2O3 and the control) with 66 samples for the thermal
conduction (n = 11) and 48 samples for the flexural strength (n = 8) tests were prepared. Flexural
strength was assessed with a three‑point bending test using a universal testing machine. One‑way
ANOVA was applied for data analysis, followed by post hoc Tukey paired group comparison
tests (P < 0.05).
Results: An increase in the aluminum oxide nanoparticle percentage in acrylic resins increased the
thermal conduction in heat‑cured acrylic resin from 2.142 ± 0.0298 to 2.487 ± 0.0359 m (2)/sec
and in self‑cured acrylic resin from 2.0150 ± 0.02646 to 2.1475 ± 0.04031 m (2)/sec and decreased
the flexural strength in heat‑cured acrylic resin from 60.521 ± 8.9278 to 49.747 ± 4.4729 MPa and
in self‑cured acrylic resin from 37.573 ± 10.9237 to 35.569 ± 6.1531 MPa (P < 0.05).
Conclusion: The incorporation of aluminum oxide nanoparticles adversely affected acrylic resin
flexural strength; however, it increased the thermal conduction.
Key Words: Aluminum oxide nanoparticles, flexural strength, nanoparticles, polymethyl
methacrylate, thermal conductivity