Evaluation of root canal dentin after Nd : YAG laser irradiation and treatment with five different irrigation solutions: A preliminary study

This study evaluated in vitro any changes in the morphology and mineral content of root canal dentin after treatments with Nd:YAG laser irradiation and 5 different irrigation solutions. The groups of extracted single-rooted human teeth were exposed to sterile saline solution, 5.25% NaOCl, 3% H2O2, 15% ethylenediaminetetraacetic acid, 2% chlorhexidine gluconate, and Nd:YAG laser irradiation. All prepared teeth were bisected longitudinally; half of each tooth was used for wavelength dispersive x-ray fluorescence spectrometry analysis to assess the mineral content. The other half was studied by using scanning electron microscopy to analyze the surface of the dentin. The results showed that the calcium level and calcium/phosphorus ratio decreased significantly with the NaOCl irrigation solutions (p < .05), suggesting the presence of changes at molecular level. Significant differences among the test groups were also observed in the scanning electron microscopy evaluation (p < .05). The lowest scores for root cleaning were obtained by using ethylenediaminetetraacetic acid followed by Nd:YAG laser treatment.