Ultra-structural evaluation of root canal dentine submitted to Nd:YAG laser irradiation associated to different chemical solutions / Avaliação ultraestrutural da dentina radicular submetida à irradiação do laser Nd:YAG associada a diferentes substâncias químicas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2005

RESUMO

The aim of this study was to evaluate the dentin morphology after the application of Nd:YAG laser, using different chemical substances used to irrigate the radicular canals. Thirty and six sound superior teeth were prepared by the Crown-Down technique and the roots were sectioned longitudinally and randomly distributed in 4 groups: distilled water; 17% EDTAC; 1% sodium hypochlorite and 2% chlorhexidine. Next, groups were subdivided according to the laser technique of application(3W, 20Hz, for 15s and perpendicularly to the surface) in the 3 thirds: dried surface before the irradiation and surface flooded for the liquid during the irradiation. The specimens were analyzed by MEV, in a double-blind study, for three calibrated examiners. The results did not demonstrate differences in dentin morphology in relation to the different root regions. In the group where surface was dried before the irradiation, regardless the substance, it was verified that the morphological alterations were more evident than the other group, due to the presence of fusion areas, boiling process, globular structures, irregularities, fissures and craters. As regards to chemical substances, it were observed that the group irrigated with sodium hypochlorite presented similar morphological aspect to the chlorhexidine, being verified fusion areas, absence of evident tubules and fissures. When laser was performed in a dried surface, it was verified fusion areas, craters, charring and tubules partially exposed. In specimens irrigated with EDTAC, it was verified the presence of surfaces without smear layer and partially opened tubules. When the irradiation was performed in water presence, the smear layer was apparently incorporated into the modified-laser surface. It may be concluded that the Nd:YAG laser promoted ultrastructural alterations in dentin surface of all studied groups. The association of EDTAC and Nd:YAG laser provided a more favorable surface standard, due to the removal of the contaminated smear layer and posterior sealing of dentin tubules.

ASSUNTO(S)

laser odontologia odontologia substâncias químicas dentistry chemical substances endodontia laser endodontics

ACESSO AO ARTIGO

Documentos Relacionados