The effect of aging methods on the fracture toughness and physical stability of an oxirane/acrylate, ormocer, and Bis-GMA-based resin composites.

Purpose: To determine the effect of aging methods on the fracture toughness of a conventional Bis-GMA-based resin composite (Filtek Supreme), an ormocer-based resin composite (Admira), and an experimental hydrophobic oxirane/acrylate interpenetrating network resin system (OASys)-based composite.

Methods: A 25 × 5 × 2.8-mm stainless-steel mold with 2.

Development of an oxirane/acrylate interpenetrating polymer network (IPN) resin system.

Objective: Develop a hydrophobic, degradation-resistant dental restorative based on an Oxirane-Acrylate IPN System (OASys) with low shrinkage-stress to substantially extend clinical lifetime.

Methods: Unfilled OASys blends were prepared using dipenta-erythritol-hexaacrylate (DPHA) and p-cycloaliphatic-diepoxide (EP5000). Varying proportions of camphorquinone/iodonium photoinitiator, with a co-reactant oligomeric-diol, served as the experimental curing system.