In order to improve the properties of a light-cured dental resin composite, diacetyl (DA) or 1-phenyl-1,2-propanedione (PD) was used as a new visible light photosensitizer for a resin composite of urethane dimethacrylate (UDMA). Phtopolymerization efficiency of UDMA and mechanical properties of experimental resin composite containing DA. or PD were compared with those of camphorquinone (CQ), the most widely used photosensitizer for dental resin composites. Photopolymerization efficiency of UDMA studied by FT-IR spectroscopy increased with irradiation time and the amount of photosensitizer. The relative properties such as Knoop hardness, diametral tensile strength, and flexural strength of the experimental resin composite prepared by the addition of the photosensitizer into a resin of UDMA were improved the photosensitizer content and irradiation time. The resin composite of UDMA containing DA or PD shows better mechanical properties than that containing CQ. A heavily filled resin composite containing DA or PD, which has a similar composition to a commercially available resin composite, Heliomolar, also shows better mechanical properties than that containing CQ.

치고용 가시광선 중합형 복합수지의 광증감재인 camphorquinone(CQ)을 대신할 수 있는 새로운 광증감제로서 diacetyl(DA) 및 1-phenyl-1,2-propanedione(PD)을 사용하여 단량체인 urethane dimethacrylate (UDMA)에 대한 공중합 효율과 기계적 성질을 관찰하였다. 이 광증감제들에 의한 UDMA의 광중합 효율을 FT-IR로 비료한 결과 DA

Keywords: visible light photosensitizer; diacetyl; phenylpropanedione; dental resin composite; urethane dimethacrylate; camphorquinone