influence of different proportions of external irrigation during the er,cr:ysgg laser irradiation on wear and roughness of root surface

introduction: the aim of this study was to evaluate the influence of different levels of external irrigation during irradiation with an erbium, chromium: yttrium-scandium-gallium-garnet (er,cr:ysgg) laser on the roughness and wear of dental tissue during scaling procedures. methods: twenty-five uniradicular bovine teeth had the proximal surfaces planed and divided into 3 regions: upper, middle and lower. the upper region was treated with hand instruments, the middle region was not treated and served as a control, and the lower region was treated by the er,cr:ysgg laser. the teeth were randomly divided into five groups according to the different proportions of external irrigation used during the laser irradiation: g1: 10%; g2: 20%; g3: 30%; g4: 40% and g5: 50%. the samples were analyzed for roughness and wear on the root surface irradiated with the laser. results: there were no differences in the surface roughness and wear parameters between the groups irradiated with the laser, but the laser irradiation produced a rougher surface of the dentin than treatment with hand scaling. conclusion: changes in the external irrigation level did not influence the wear and roughness of root surfaces treated with an er,cr:ysgg laser