Acceleration of curing of resin composite at the bottom surface using slow-start curing methods

Abstract

The aim of this study was to evaluate the effect of two slow-start curing methods on acceleration of the curing of resin composite specimens at the bottom surface. The light-cured resin composite was polymerized using one of three curing techniques: (1) 600 mW/ cm2 for 60 s, (2) 270 mW/cm2 for 10 s+0-s interval+600 mW/cm2 for 50 s, and (3) 270 mW/cm2 for 10 s+5-s interval+600 mW/cm2 for 50 s. After light curing, Knoop hardness number was measured at the top and bottom surfaces of the resin specimens. The slow-start curing method with the 5-s interval caused greater acceleration of curing of the resin composite at the bottom surface of the specimens than the slow-start curing method with the 0-s interval. The light-cured resin composite, which had increased contrast ratios during polymerization, showed acceleration of curing at the bottom surface.