Comparative Evaluation of the Effects of CO_2 and Er:YAG Lasers on Smear Layer Removal and Blood Cell Attachment to Tooth Root Surfaces

Introduction: the tooth root surfaces are modified by different agents for better removal of the smear layer, the formation of fibrin clots, and the attachment of blood cells. this in vitro study compared the removal of the smear layer, the formation of fibrin clots and the attachment of blood cells after exposing periodontally compromised root surfaces to er:yag and co_2 laser beams. methods: eighteen dentin block samples were prepared from freshly extracted periodontally compromised teeth that were deemed hopeless, and they were divided into 3 groups: exposed to er:yag laser beams, exposed to co_2 laser beams, and the control group. the samples were evaluated using scanning electron microscopy and micrographs were taken. smear layer removal and blood cell attachment were scored. data were analyzed using kruskal-wallis and mann-whitney tests. results: in the er:yag laser group, the smear layer was removed completely. in the specimens exposed to blood, better fibrin clot formation and blood cell attachment were observed in the er:yag laser group. in the co_2 laser group, the smear layer was also removed; however, there were no significant differences between the co_2 laser and control groups in fibrin clot formation and blood cell attachment. conclusion: the application of the er:yag laser to the root dentin appears to result in the formation of a suitable surface for fibrin clot formation and blood cell attachment. further clinical studies are necessary to support these results.