ESTEVES OLIVEIRA, MARCELLACARVALHO, WENDELL L.EDUARDO, CARLOS de P.ZEZELL, DENISE M.2014-07-152014-07-302014-07-152014-07-302008ESTEVES OLIVEIRA, MARCELLA; CARVALHO, WENDELL L.; EDUARDO, CARLOS de P.; ZEZELL, DENISE M. Influence of the additional Er:YAG laser conditioning step on the microleakage of class V restorations. <b>Journal of Biomedical Materials Research, B</b>, v. 87, n. 2, p. 538-543, 2008. DOI: <a href="https://dx.doi.org/10.1002/jbm.b.31141">10.1002/jbm.b.31141</a>. Disponível em: http://repositorio.ipen.br/handle/123456789/5096.1552-4973http://repositorio.ipen.br/handle/123456789/5096The purpose of this study was to evaluate the influence of an additional Er:YAG laser conditioning step after laser cavity preparations, on the microleakage of class V composite restorations. Forty-eight bovine incisors were randomly divided into four groups: G1(control) cavities prepared with bur, G2- cavities prepared with laser (400 mJ/2 Hz), G3- cavities prepared and subsequently conditioned with Er:YAG laser (60 mJ/2 Hz); G4-idem for G3, but the laser conditioning was carried out without water-spray. All the cavities were restored using Clearfill SE Bond® and Z-250® composite resin. The samples were thermal cycled for 700 cycles and then immersed in 50% silver nitrate solution. The sectioned restorations were exposed to a photoflood lamp to reveal silver nitrate penetration. The Kruskal-Walis one-way analyses of variance test and post hoc Wilcoxon pair-wise comparison were used to compare microleakage degrees. At the gingival margin G2 showed a lower microleakage mean than the control bur-prepared cavities (p = 0.0003). At occlusal margins there were no statistically significant differences between the groups (p = 0.28). It may be concluded that Er:YAG laser class V cavity preparations do not need to be followed by an additional laser conditioning step to result in levels of microleakage similar to or lower than those obtained after bur preparations.538-543closedAccesslaserserbiumteethdentinenamelsoral cavitybiological recoveryArtigo de periódico28710.1002/jbm.b.31141https://orcid.org/0000-0001-7404-9606