Mechanical strength of urethane-based visible-light-cured resins

In experimental urethane-based visible-light-cured(VLC) resins containing a diluent monomer, a lower value of activation energy for polymerization than in bis-GMA-based VLC resin was obtained. A greater increased diametral tensile strength and slightly larger compression strength were observed. The diluent monomer in the urethane-based VLC resins gives an increase of strength, associated with lower activation energy for polymerization, compared with the bis-GMA-based resin.