Thermoplastic polymer blend as novel material for denture base

To develop new polymer blend, the glass transition temperature (Tg) and flexural properties including flexural strength and flexural modulus of thermoplastic polymer blend between poly(methyl methacrylate) and poly(lactic acid) (PMMA/PLA blend) were investigated and compared to currently available denture base materials. Thermoplastic injection PMMA/PLA blend (PB), fuse-deposition modelling PLA (FL), thermoplastic injection polyamide (VP), and heat-polymerized compression molding PMMA (CM) are the 4 polymers employed in this investigation. The Tg of each material was investigated with differential scanning calorimetry. The eight bar-shaped specimen size 65 × 10 × 3.3 mm of each group were fabricated with the proper condition of each material. The specimens were polished and immersed in 37°C water for 48 hours prior to flexural testing by universal testing machine. The testing conditions complied with ISO 20795-1. The data of flexural strength and flexural modulus was collected and analyzed by one-way ANOVA with post-hoc test. The CM group showed the highest Tg followed by PB, FL, and VP groups, accordingly. The flexural strength of PB group was the highest but not was significantly different from CM group, while VP group showed the lowest flexural strength. The PB group also showed the highest flexural modulus than the others while VP group showed the lowest flexural modulus. By blending PMMA with PLA, Tg of the material could be increased to the level suitable for intra-oral usage. Because it has the comparable flexural strength, and higher flexural modulus than that of conventional heat-polymerized PMMA, thermoplastic injection PMMA/PLA blend could be alternative material for denture base.