Characterization of experimental composite biomaterials

A comparison was made among the elastic moduli of various combinations of dimethacrylates that may be used as matrix resins in dental restorative composite biomaterials systems. Two ceramic filler materials with contrasting shape and size were synthesized by wet chemistry; these were used to produce a range of experimental composite systems. Dynamic elastic moduli determinations were used to study the influence of filler volume, filler size/shape, use of silane coupling agents, and storage in water. The filler was varied from 0 to 59% by volume for filler A and from 0 to 48% volume for filler B. Silane treatment was found to have a significant effect on modulus. Moduli for composite materials containing silane-treated filler were higher compared to materials containing the same volume loading of non-silane-treated filler. Using a light curing resin as a matrix gave a significantly higher modulus for a filler loading of 38% by volume. Storage in water for 29 days was found to have only a slight effect on moduli for composite systems containing in excess of 20% by volume of filler. The experimental composite systems produced slightly higher values for moduli than were predicted by the theoretical Reuse constant stress model.