Micromorphological analysis of dentinal structure after irradiation with Nd:YAG laser and immersion in acidic beverages.
Mo kle
Abstrè
OBJECTIVE
The purpose of this study was to analyze dentinal surfaces that were exposed to acidic beverages, then treated with Nd:YAG laser and afterwards exposed to acidic beverages again.
BACKGROUND
Dentin hypersensitivity can result from surface erosion caused by acidic beverages, which exposes and enlarges the dentinal tubules. Nd:YAG laser has been used as a treatment option.
METHODS
Sixty-eight dentin samples were prepared and assigned to five groups: G1, control (n = 4); G2, 3-h immersion (n = 16); G3, 3-h immersion + Nd:YAG; G4, 3-h immersion + Nd:YAG + 3-h immersion; and G5, 3-h immersion + Nd:YAG + 6-h immersion. Each group was divided into four subgroups, with different acid beverages: lemon (n = 4); passion fruit (n = 4); cola (n = 4); and wine (n = 4). Irradiation with the Nd:YAG was in contact mode, focused and perpendicular through a quartz fiber of 300 microm of diameter in scanning movements for 60 sec with a 10-sec interval and the paramenters 0.6 W, 10 Hz, 60 mJ, and 85 mJ/cm(2). Each subgroup was examined by scanning electron microscope.
RESULTS
All the acidic beverages contributed to exposure and increased diameter of the dentinal tubules.
CONCLUSIONS
Irradiation with Nd:YAG laser produced obliteration of and reduction in the number of dentinal tubules, thus modifying the original structure.
