Purpose: To analyze in vitro the ablative and etching effect of the Er:YAG laser on the enamel of extracted teeth using scanning electron microscopy, comparing two different laser parameter settings. Materials and Methods: Ten noncarious extracted human third molars were treated with an Er:YAG (2940 nm wavelength) set at different parameters. Changes in enamel were observed using scanning electron microscopy. Results: SEM observation of dental hard tissue showed that excessive energy parameters did not give the same results in all the samples, because of the presence of induced alterations (microcracks, melting, flakes) resulting from the thermal effect. Conclusion: This study confirms the possibility of performing ablation within defined limits, forming microcavities with a finely etched and rough surface that are well prepared for treatment with adhesive restorative materials. For best results, it is recommended to use lower levels of energy, emitted at a higher repetition rate.

Keywords: Er:YAG laser, laser etching, power density, fluence, focus, scanning electron microscopy