[An analysis by scanning electron microscopy and surface roughness meter of the impact of the CO2 laser on the dentin].

The aim of the study was to compare the morphology of craters produced on the dentinal surface by CO2 laser beams (LASERSAT CO2) before and after the removal of the carbonized layer, besides with different settings of the power and duration of the laser beam. Thirty-three recently extracted non carious young third molar teeth were sectioned from vestibular and lingual surfaces, exposing a planed dentinal surface. Twenty impacts were made on each of dentinal surface producing 20 individual craters. The duration and the power of each laser beam were different on each tooth. The duration varied from 0.1 to 0.4 second (0.1-0.2-0.3-0.4 s). The power varied from 1 to 5 watts (1, 2, 3, 4, 5 w). Specimens obtained for a power of 3 and 4 watts and a duration of 0.1 and 0.2 second were examined with a JEOL 35CF (25 KV, magnification: x 30, x 110, x 200), before and after the removal of the carbonized layer. The carbonized layer of the craters was removed with an air polisher (HEATCO). Craters obtained for all duration values as well as for all power values were analyzed with a profilometer. The chosen profilometer was: TALISURF 10; horizontal amplification Vh = 20; vertical amplification Vv = 200. Samples were observed by a SEM and the craters depth and diameter were measured with a profilometer. Then, the carbonized layer of the craters was removed with an air polisher and the cleaned dentinal surface was observed again with the SEM and the profilometer.(ABSTRACT TRUNCATED AT 250 WORDS)