Morphologic analysis, by means of scanning electron microscopy, of the effect of Er: YAG laser on root surfaces submitted to scaling and root planing

Abstract

The purpose of this study was to morphologically evaluate, by means of scanning electron microscopy, the effects of Er:YAG laser on the treatment of root surfaces submitted to scaling and root planing with conventional periodontal instruments. Eighteen root surfaces (n = 18), which had been previously scaled and planed, were assigned to 3 groups (n = 6). The control Group (G1) received no further treatment; Group 2 (G2) was irradiated with Er:YAG laser (2.94 mum), with 47 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 0.57 J/cm of fluency per pulse; Group 3 (G 3) was irradiated with Er:YAG laser (2.94 mum), with 83 mJ/10 Hz, in a focused mode with air/water spray during 15 s and with 1.03 J/cm2 of fluency per pulse. We concluded that the parameters adopted for Group 3 removed the smear layer from the root surface, exposing the dentinal tubules. Although no fissures, cracks or carbonized areas were observed, an irregular surface was produced by Er:YAG laser irradiation. Thus, the biocompatibility of the irradiated root surface, within the periodontal healing process, must be assessed.

Effect of Er,Cr:YSGG and Er:YAG laser irradiation on the adhesion of blood components on the root surface and on root morphology

“…4,7 The surfaces irradiated with Er:YAG and Er,Cr:YSGG lasers showed similar morphological characteristics, including root surface roughness, no smear layer, open dentinal tubules and lack of thermal damage. These characteristics are consistent with those observed in other in vitro studies that evaluated the morphology of dentin irradiated with Er:YAG 4,8,11 and Er,Cr:YSGG lasers. 7,9,12,13 The morphological characteristics of the surfaces irradiated with these lasers are explained by the laser tissue ablation mechanism, called photomechanical ab- …”

“…One possible explanation for this is that surfaces irradiated by the Er,Cr:YSGG laser are relatively more thermally affected than those irradiated by the Er:YAG laser, insofar as the ablation produced by the Er:YAG laser is initiated at temperatures of approximately 300°C, whereas that produced by the Er,Cr:YSGG laser is initiated at approximately 800°C. 5 On the other hand, studies that evaluated the adhesion of fibroblasts 10 and blood elements 13 on root surfaces irradiated with the Er,Cr:YSGG laser showed that irradiated surfaces present a biocompatibility greater than 10 or comparable 11,13 to that of surfaces scaled with hand tools. This may have occurred owing to the work angles used in these studies (~20-30° 10 and ~45° 13 ), smaller than those used in our study.…”

“…Studies that have evaluated the influence of the irradiation angle on root surface morphology have shown that greater angles of irradiation promote higher wear on root surfaces, 11,15 and this occurs because the removal of tissue is related to the energy density, 16 which, in turn, is directly proportional to the irradiation angle. 15 .…”

“…21 Another important feature is the presence of open dentinal tubules that may induce cervical dentin hypersensitivity in subjects where the root surface is exposed to the oral environment. 11 In both cases, one should take into account that after periodontal treatment, the inflamed gingival margin will retract, and surfaces that were once subgingivally located will eventually become supragengival. 13 …”

Clinical and Microbiologic Follow‐Up Evaluations After Non‐Surgical Periodontal Treatment With Erbium:YAG Laser and Scaling and Root Planing

“…High‐intensity lasers have been used to promote periodontopathogen reduction 4 and also for scaling and root planing (SRP) 5‐11 . The erbium‐doped: yttrium, aluminum, and garnet (Er:YAG) laser has a wavelength of 2.94 μm and it may have bactericidal effects and potential to remove bacterial endotoxins and calculus from the root surface, due to its high water absorption capacity.…”