title: In vitro radiographic analysis of Nd:YAG-laser-irradiated dentin.
abstract: The aim of this study was to evaluate the effects of Nd:YAG laser irradiation on the dentin radiographic image. Previous studies have shown that Nd:YAG laser irradiation is capable of promoting morphological and chemical changes of the dentin surface, indicating the possibility of an alteration of its radiographic image. Dentin of 2-mm-thick mid-coronal sections from 68 extracted posterior teeth was irradiated for 30 s by a Nd:YAG laser (lambda=1,064 nm) on one half of its surface area. The other half was left as a control. The irradiation parameters were: 80 mJ/pulse, 0.8 W, 10 Hz, with a 320-mum flexible quartz optic fiber in contact mode. The 68 samples were radiographed with a 70-kV X-ray setup. The focus-film distance was established as 30 cm and there was no distance between the object and the film. The X-ray exposure time was set as 0.16 s and the radiographic film used was an F-speed dental film. The obtained radiographic images were submitted to a densitometric analysis. The images analyzed showed that there were statistically significant differences between the density of the irradiated dentin images and the non-irradiated dentin images. The image density data showed that the irradiated dentin radiographic images were 6.36% more radiopaque than the non-irradiated dentin images. The Nd:YAG laser irradiation of dentin is able to alter its radiographic image, producing more radiopaque images of the irradiated dentin.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, São Paulo University, Av. Prof. Lineu Prestes 2227, CEP, 05508-900, São Paulo, Brazil.
authors.forename: H C P
authors.initials: HC
authors.lastname: Brucoli
authors.forename: E S
authors.initials: ES
authors.lastname: Arita
authors.forename: C P
authors.initials: CP
authors.lastname: Eduardo
mesh_terms: D015502:Absorptiometry, Photon; D000535:Aluminum; D003804:Dentin / Q000000981:diagnostic imaging* / Q000528:radiation effects* / Q000648:ultrastructure; D006801:Humans; D007834:Lasers; D009354:Neodymium; D015019:Yttrium
chemical_list: C503779:yttrium-aluminum-garnet; D009354:Neodymium; D015019:Yttrium; D000535:Aluminum