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

Abstract

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 0.5e5 wt% aluminum oxide (Al 2 O 3 ) 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 Z 10) coded A to E. Group A was the control group (without adding Al 2 O 3 ). Specimens in the other four groups (BeE) were reinforced with Al 2 O 3 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% Al 2 O 3 significantly increased the flexural strength compared to the control group (P Z 0.000). The Vickers hardness significantly increased (P < 0.05) after incorporation of 2.5 and 5 wt% Al 2 O 3. 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% Al 2 O 3 powder significantly increased its flexural strength and hardness with no adverse effects on the surface roughness.

The effects of adding various ratios of zirconium oxide nanoparticles to poly(methyl methacrylate) on physical and mechanical properties

“…Previous studies have mostly concluded that reinforcing acrylic resins with ceramic particles can provide some improvements in surface hardness (6,17); these findings are in agreement with the results for group 1 in the present study and are not in agreement with those for group 3 due to nonhomogeneous nanoparticle dispersion and low ionic interatomic bonding. Similarly, Asopa et al (3) reported that 10% and 20% of nano-ZrO 2 addition to PMMA resulted in a significant increase in flexural strength but a decrease in surface hardness.…”

“…Moreover, hardness measurement has been used as an indirect method of evaluating polymerizing depth of resin-based materials (17). Moreover, hardness impacts the surface characteristics of PMMA indicating the ease of finishing a material (6). These days, nano-ZrO 2 is used to fabricate reinforced denture base materials with high hardness (17,28).…”

“…Various methods have been attempted to increase the strength of acrylic denture base and decrease the risk of denture fracture (6,7). Studies show that administering an appropriate additive to PMMA can improve the propZirconium oxide (ZrO 2 ) is a metal oxide that possesses several advantages such as good mechanical strength, fracture toughness, hardness, wear and chemical resistance, and good thermal stability, thus making it beneficial for use in dental materials such as denture base reinforcement (4,8,11,12).…”

Effect of Zirconium Oxide Nano-Fillers Addition on Mechanical Properties of Heat-Polymerized Acrylic Resin

“…There is no significant improvement in fracture toughness values of the modified acrylic resin at the concentrations of ZrO 2 above that limit ( 5% wt and 7% wt).It is probably due to complete saturation of the polymer matrix with the ZrO 2 particles. [31] Improvement of hardness with the increase in concentration of ZrO 2 nanofillers may have be due to inherent characteristics of the ZrO 2 particles. ZrO 2 possesses strong ionic interatomic bonding, giving rise to its desirable material characteristics, that is, hardness and strength.…”

Polyamide as a denture base material- a review

“…These often lead to denture failure during chewing or when fall out of the patient's hand. In order to enhance some properties of PMMA, various efforts have been taken including addition of metal wires or plates, fibers, [3][4][5][6] metal dification of chemical structure. In recent ted attention as a denture base materials.…”