"In vitro" evaluation of morphologic changes on the root dentine irradiated by CO2 laser associated or not to calcium hydroxide

Abstract

This in vitro study has evaluated the structural changes on the root dentine irradiated by a CO2 laser associated or not to calcium hydroxide - an alternative method for dentine hypersensitivity treatment. Fourteen human teeth 3rd molars were utilized, divided into 7 groups. Group I (control group),Groups II, III and IV received an application of Ca (OH)2 paste followed by CO2 laser irradiation for 5 seconds, intervals of 10 seconds, continuous emission, power of 0.5W, constant distance of 30mm (Group II), 1.0W (Group III), 1.5W (Group IV); Groups V, VI, VII received laser irradiations following the same parameters applied to groups II, III, and IV. Morphologic changes suggesting to fusion and re-solidification were observed, and the presence of material obstructing the whole analyzed surface on groups II, III, and IV. For groups V, VI, and VII, fusion, re-solidification, and cracks, were observed, results statistically significant (P<0,01). No statistically significant differences were observed in groups that used the same treatment. Powers above 1.0W (DP=125,38W/cm2) showed carbonization and dark surface, results unfavorable due to the undesirable morphologic alterations and aesthetic compromising.