ABSTRACT
The effects of laser etching on dentin are studied by microenergy-dispersive x-ray fluorescence spectrometry (µ-EDXRF) and scanning electron microscopy (SEM) to establish the correlation of data obtained. Fifteen human third molars are prepared, baseline µ-EDXRF mappings are performed, and ten specimens are selected. Each specimen received four treatments: acid etching (control-CG) or erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation (I-100 mJ, II-160 mJ, and III-220 mJ), and maps are done again. The Ca and P content are significantly reduced after acid etching (p<0.0001) and increased after laser irradiation with 220 mJ (Ca: p<0.0153 and P: p=0.0005). The Ca/P ratio increased and decreased after CG (p=0.0052) and GI (p=0.0003) treatments, respectively. CG treatment resulted in lower inorganic content (GI: p<0.05, GII: p<0.01, and GIII: p<0.01) and higher Ca/P ratios than laser etching (GI: p<0.001, GII: p<0.01, and GIII: p<0.01). The SEM photomicrographies revealed open (CG) and partially open dentin tubules (GI, GII, and GIII). µ-EDXRF mappings illustrated that acid etching created homogeneous distribution of inorganic content over dentin. Er:YAG laser etching (220 mJ) produced irregular elemental distribution and changed the stoichiometric proportions of hydroxyapatite, as showed by an increase of mineral content. Decreases and increases of mineral content in the µ-EDXRF images are correlated to holes and mounds, respectively, as found in SEM images.
Subject(s)
Acid Etching, Dental/methods , Dentin/chemistry , Lasers , Molar, Third/radiation effects , Tooth/radiation effects , Algorithms , Aluminum , Erbium/chemistry , Humans , Microscopy, Electron, Scanning , Surface Properties , YttriumABSTRACT
Os diastemas nos dentes anteriores são vistos como um fator antiestético e a busca pelo belo tem se intensificado nos últimos anos. Com o desenvolvimento das porcelanas e dos sistemas adesivos, as facetas de porcelana têm apresentado ótimos resultados estéticos, biológicos e funcionais ao longo do tempo. Porém, o sucesso do tratamento depende do conhecimento das propriedades e limitações do material, bem como do domínio da técnica. O objetivo deste artigo é apresentar um caso clínico de fechamento de diastema utilizando facetas de porcelana