Photochemical Studies on Composite Resins Cured by Visible Light

The characteristics of the method of curing resin using visible light was examined, photochemically. Commercially available light curing units emitted much unnecessary light, predominantly in a long wavelength range. The internal hardness of cured resins increased with argon ion laser output along with deep hardness, but the maximum hardness was not always increased. The degree of polymerization of the commercially available composite resins measured using a laser Raman spectrophotometer was about 55 -70%, which indicated that there is ample room for improvement. The degree of polymerization of bonding agents in dentinal tubule determined by laser Raman microspectroscopy was about 80-85%.