Comparison Fracture Strength of Injection Mold, Heat Cure and Self Cure Type by Three Point Bending Test

 Fracture of the denture base and its repair are one of the main concerns of patients with a complete denture. This is often due to patients’ carelessness in maintaining dentures, or a low strength and resistance of the acrylic resin. This study aimed to compare the fracture resistance of heat-cured, self-cured, and injectable acrylic resins using a three-point flexural test.

 In this experimental study, 30 blocks of acrylic resin (Ivoclar VivaDent-Liechtenstein), measuring 2.5×25×50were prepared with three methods of heat-cured¸ self-cured, and injection. The samples were incubated for 24 hours to simulate the oral conditions. The samples were then subjected to three-point flexural testing in a universal testing machine. The force required for the failure of the samples was measured, and the results were compared and analyzed using Kruskal-Wallis and Wilcoxon tests with SPSS 22 (α = 0.05).

 Among the three samples, the fracture resistance of the self-cured acrylic resin was the lowest, and the fracture resistance of the injected acrylic resin was the highest. The differences in fracture resistance between the acrylic resins were significant (p value < 0.001).

 Since the injected acrylic resin exhibited the highest fracture resistance, it is more appropriate for the fabrication of fracture-resistant dentures.