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

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.

In this in vitro study, a total of 114 samples consisting of heat‑ and self‑cured three subgroups (1% and 3% Al2 O3 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).

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).

The incorporation of aluminum oxide nanoparticles adversely affected acrylic resin flexural strength; however, it increased the thermal conduction