The present study investigated the feasibility of a high short-rod fiber content in denture base resins using polymethylmethacrylate (PMMA) powder with a small particle diameter. The effects of fiber contents on mechanical properties of composite resins were studied.
A commercial denture base PMMA powder (AC; average particle size, 150 μm) and an industrial PMMA powder (MB; average particle size, 4 μm) were selected. Short-rod glass fibers were mixed with the two powders at a mass ratio of 0-50%. Flexural strengths and moduli of the mixtures were evaluated by a three-point bending test.
The flexural strength of AC composites did not change regardless of fiber content, while that of MB composites increased significantly at fiber contents exceeding 40%. The flexural moduli of AC and MB composites at fiber contents exceeding 20% were significantly greater than those of AC and MB resins without short-rod glass fibers, respectively.