Visible lights and visible light-activated composite resins

Abstract

U ltraviolet light (W)-activated composite resins serve a useful purpose.‘,* The depth of cure provided by the various UV systems has contributed to their acceptance.3 Recently, the visible light-activated composite resins have gained in popularity. At the start of this investigation, there were 11 visible light-activated composite resins and eight visible lights for their polymerization on the market. Some manufacturers claim 4 mm depth of polymerization in a 20-second exposure to a visible light. This depth is greater and the exposure time shorter than that reported for UVactivated composite resins.3 There have been several reports on visible lightactivated systems.4-9 Swartz et al.’ found that these resins could be polymerized through 1 mm of enamel. Like Swartz et al.,4 Leung et aL5 found that a greater exposure time increased the hardness of the specimen at a particular depth. All studies were made in metal or plastic molds except for one cliaical report.‘j The purpose of this study was to compare the depth of polymerization in teeth of combinations of 11 visible light-activated composite resins and the eight visible lights. These results were compared with those obtained from the previous study on W-activated systems.3