An alternative method of polymerization involves the gradual exposure of resin composite material to the light-activating lamp. This process is intended to facilitate the internal flow of the resin during the hardening phase, resulting in a better adaptation of the restoration to the cavity walls. A regulating device is added to a conventional lamp to allow a gradual increase in intensity of the emitted light until it attains the values emitted in normal use. This study compared the adherence of resin composite to dentin after conventional polymerization or polymerization with the slow and gradual technique. The resin composite-dentin interface in replicas obtained from longitudinal sections of the specimens was examined by scanning electron microscopy. Results revealed that it was possible to improve the adaptation of resin composites to the dentinal surface by reducing the speed of polymerization.