Effect of pulse duration of Er:YAG laser on the dentin surface morphology

The purpose of this study was to investigate the effects of different pulse durations of Er:YAG laser on the morphology of human dentin. Dentin discs obtained from extracted human third molars were exposed to a single pulse irradiation with an Er:YAG laser at 150 mJ/pulse and 80, 100, 150, 200, 250, 300, 400 and 500 μs of pulse duration. The irradiated surfaces and the cross sections were evaluated using an scanning electron microscope (SEM). There was no difference among the diameters of each irradiated area. The morphology pattern was similar in the 80 to 200 μs, without melted surfaces. The 250 to 500 μs groups presented more melted surfaces. It was concluded that the difference of pulse duration partially affected the pattern of the irradiated dentin surface.