DENTURE BASE RESIN REINFORCED WITH HIGH-PERFORMANCE POLYETHYLENE FIBER - WATER SORPTION AND DIMENSIONAL CHANGES DURING IMMERSION

Reinforcement of acrylic denture base resin with high-performance polyethylene fiber in various forms (chopped, woven, and continuous parallel) resulted in a significant reduction of both water sorption at saturation and dimensional changes taking place during immersion. Incorporation of the fibers does not decrease the rate of approach to equilibrium, and in some cases, this is increased. The nonsteady state for each system can be described in terms of a ''Fickian''-type diffusion process. Diffusion coefficients can be calculated with water uptake or with dimensional changes data, both giving similar values for any given system.