The effect of aluminum oxide addition on the flexural strength of heat activated acrylic resin: An in vitro study

Abstract

Aim: This study was done to investigate the effect of adding 5-20% aluminum oxide (Al 2 O 3 ) powder by weight on the flexural strength of heat-polymerized acrylic resin. Materials and Methods: A total of 50 specimens of heat-polymerized acrylic resin were fabricated and were divided into five groups (n = 10). Group A was the control group (unmodified acrylic resin specimens). The specimens of the remaining four groups i.e., Groups B, C, D and E were reinforced with Al 2 O 3 powder to achieve loadings of 5%, 10%, 15% and 20% by weight. Specimens were stored in distilled water for 1 week and the flexural strength of the specimens was tested in a universal testing machine (5 mm/min crosshead speed). Results were analyzed by one-way analysis of variance. Weibull analysis was used to calculate the Weibull modulus, characteristic strength and the required stress for 1% and 5% probabilities of failure. Results: The mean flexural strength values of the heat-polymerized acrylic resin were (in MPa) 92.01, 114.46, 116.77, 123.11 and 129.72, for Groups A, B, C, D and E, respectively. The flexural strength increased significantly with the incorporation of Al 2 O 3 . Conclusion: Al 2 O 3 fillers are potential components to be added in denture bases to provide increased flexural strength. Adequate flexural strength of denture base is quite essential for the longevity of the prosthesis.