Factors that affect the rheologic properties of acrylic resin denture base materials.

The rheologic characteristics of different formulations of acrylic resin denture base materials are presented in this study. This is of practical significance in selecting resins with optimum rheologic properties for denture base construction. The materials are characterized in respect to their constituents, mean powder particle size and distribution, molecular weight averages and distributions, and glass transition temperature. A comparison of the polymers indicates that smaller particles saturate with monomer more readily, and this results in a higher viscosity. A higher viscosity for higher molecular weight and lower viscosity for lower molecular weight have been observed. Increasing the percentage of copolymerization increases the viscosity. No correlation has been found between the rheologic properties of denture base polymers and the powder glass transition temperature.