In Vitro Evaluation of the Fracture Strength among Three Different Denture Base Materials

Failure in the form of denture fracture is commonly encountered by both removable prosthodontics wearers and dentists, it is mainly attributed to material properties, technical features, stresses while in function or due to impact as a consequence of dropping the dentures. Traditionally, Heat-Polymerized Polymethylmethacrylate (PMMA) has been the gold standard for denture bases due to its ease of processing and acceptable mechanical properties. However, newer materials, injectable flexible nylon-based resin and CAD/CAM Polyether ether Ketone (PEEK) denture bases are being introduced with claims of superior strength and durability. The aim of this study was to investigate the fracture strength of three commonly used denture base materials in Libya, which may aid in selecting the best material for a given application and predicting potential material behavior under load when holding the durability of the material in mind. A total of 36 samples were tested. These samples were divided into three groups, with 12 samples each: Group I heat polymerized acrylic resin PMMA, group II Injectable flexible nylon-based resin and group III CAD/CAM (PEEK). The fracture strength test was carried out on a universal testing machine at a crosshead speed of 5 mm/min. The results were analyzed using ANOVA, and multiple comparisons were undertaken using Tukey’s HSD test. Statistical significance was set at P ≤ 0.001. The result of this study shows there were significant differences in the fracture strength among the three groups (P< 0.001). Moreover, CAD/CAM (PEEK) denture base material exhibited significantly the highest fracture strength (234.17N ± 13.5) whereas the least fracture strength value was measured with Injectable flexible nylon-based resin denture base material (75.25N±10.5). The study concluded that, within the limitations of this study, the results demonstrate that CAD/CAM (PEEK) outperforms Injectable flexible nylon-based resin and heat polymerized acrylic denture base materials in terms of the fracture strength, supporting its potential as an advanced material for denture construction. However, further clinical studies are recommended.