October 2013

Objective: This study evaluated the effect of desensitizing agents associated with a laser diode on dentin permeability and surface morphology. Methods: One hundred four bovine root dentin specimens were randomly divided into four groups and two subgroups (n = 13): G1A = no treatment (control), G1B = diode laser, G2A = Oxagel, G2B = diode laser + Oxagel, G3A = MI PasteTM, G3B = diode laser + MI PasteTM, G4A = Sensitive Pro-ReliefTM in-office, G4B = diode laser + Sensitive Pro-ReliefTM in-office. For permeability analysis, 10 specimens from each subgroup were immersed in 1% hydrochloric acid (three times for 20 seconds at intervals of 2 hours) to expose the dentinal tubules. The application of desensitizing agents was performed according to the manufacturer’s instructions and irradiation with the laser diode was made for 25 sec (contact mode, 970 nm ± 10 nm, 0.7W CW, 10 Hz). After that, the permeability was measured in digitized images in an optical microscope. The remaining specimens (n = 3) were divided into two areas (control and experimental) and the surface morphology was analyzed using scanning electron microscopy. The permeability values were analysed using analysis of variance (ANOVA). Results: For dentin permeability, no statistically significant differences were noted among the treatments. No significant differences were verified on the dentin surface by scanning electron microscopy. Conclusion: The desensitizing agents alone or associated with a diode laser did not affect the root dentin permeability and the dentin surface morphology.