Engineering a hydration-responsive PMMA denture base using potassium polyacrylate

Abstract

Objective: This research aimed to identify the characteristics and the impact of potassium polyacrylate (KPA) as a heat-polymerised PMMA additive on the water sorption behaviour, mechanical property, surface characteristics, and cytocompatibility.

Methods: PMMA specimens were fabricated in different KPA concentrations (0, 0.5, 2.5 and 5 wt%). Water sorption and solubility tests were performed according to ISO’s guidelines. Mechanical characteristics were determined by three-point bending and Vickers hardness tests. Surface characteristics and chemical stability were investigated using scanning electron microscopy and Fourier transform infrared spectroscopy. MTT assay was performed on fibroblast cell cultures to determine cytocompatibility.

Results: Water sorption, but not solubility, increased with the addition of the KPA in a concentration-dependent manner. Measurement of mechanical properties showed a gradual decrease in both flexure strength and hardness values by increasing KPA content, but all were within clinically acceptable ranges. Uniformly dispersed at lower loading levels and micro-porous controllability at higher concentrations without PTMS degrading the PMMA matrix was observed in the microscopic analysis. The cytotoxicity test revealed high cell viability for all the formulations, suggesting that biocompatibility was maintained.

Conclusion:  PMMA modified with potassium polyacrylate exhibits enhanced hydration while maintaining an acceptable mechanical and biological performance. The application of mixed-in additives for a multifunctional denture base material may have some potential merits to xerostomic patients, and such ways in prosthetic biomaterials design will be a great future.