Abstract
Objectives: The purpose of this in vitro study was to determine whether there is a change in dentin permeability following 9.6-μmm CO2 laser irradiation and high-speed drilling. Materials and Methods: Twenty permanent, intact, non-carious molars were selected. The crowns were separated from the roots at the cemento-enamel junction. The teeth were randomly divided into two groups, control and experimental, each containing 10 teeth. After class I preparation using a high-speed drill, 9.6-μm CO2 laser irradiation was applied to dentinal areas only on the experimental group. The samples were soaked in 0.5% methylene blue for 48 h; three independent examiners using scanning electron microscopy evaluated dye penetration through the specimens. Results: The results of the three examiners were similar. There was a significant difference in dye penetration into dentin after laser irradiation versus controls (p < 0.05). Conclusions: The 9.6-μm CO2 laser appears to be a promising tool in the clinical setting. However, further investigation is needed to ensure maximum effectiveness.