US EPA

1768966 

Journal Article 

Effects of aluminum oxide addition on the flexural strength, surface hardness, and roughness of heat-polymerized acrylic resin 

Vojdani, M; Bagheri, R; Khaledi, AAliR 

2012 

Yes 

Journal of Dental Sciences
ISSN: 1991-7902 

7 

3 

238-244 

10.1016/j.jds.2012.05.008 

WOS:000310719500005 

Background/purpose: Acrylic dentures frequently fracture
during service due to their poor strength characteristics. The aim of this study was to evaluate
the effects of adding 0.5-5 wt% aluminum oxide (Al2O3) powder on the flexural strength, surface
hardness, and roughness of a conventional heat-polymerized acrylic resin. Materials and methods:
In total, 50 specimens were prepared for each test. Specimens were divided into five groups (n =
10) coded A to E. Group A was the control group (without adding Al2O3). Specimens in the other
four groups (B-E) were reinforced with Al2O3 at loadings of 0.5, 1, 2.5 and 5 wt%. Flexural
strength was assessed with a three-point bending test using a universal testing machine. Hardness
testing was conducted using a Vickers hardness tester. A surface-roughness test was performed
with a profilometer. Results: Data analyses using analysis of variance and Tukey'shonest
significant difference tests showed that adding 2.5 wt% Al2O3 significantly increased the
flexural strength compared to the control group (P = 0.000). The Vickers hardness significantly
increased (P < 0.05) after incorporation of 2.5 and 5 wt% Al2O3. No significant difference (P >
0.05) was detected in surfaceroughness levels between the reinforced and control groups.
Conclusion: Reinforcement of the conventional heat-cured acrylic resin with 2.5 wt% Al2O3 powder
significantly increased its flexural strength and hardness with no adverse effects on the surface
roughness. Copyright (c) 2012, Association for Dental Sciences of the Republic of China.
Published by Elsevier Taiwan LLC. All rights reserved. 

aluminum oxide; acrylic resin; hardness; roughness; flexural strength