Effect of final irrigation protocols on microhardness and erosion of root canal dentin.

The aim of this study was to evaluate the effect of final irrigation protocols (17% EDTA, BioPure MTAD, SmearClear, and QMiX) on microhardness and erosion of root canal dentin. Fifty roots were sectioned transversely at the cement-enamel junction and each root was sectioned horizontally into 4-mm-thick slices. The samples were divided into five groups (n = 10) according to the final irrigation protocol: G1: distilled water (control group); G2: 17% EDTA; G3: BioPure MTAD; G4: SmearClear; and G5: QMiX. The dentin microhardness was then measured with a load of 25 g for 10 s. Initially, the reference microhardness values were obtained for the samples without any etching. The same samples were then submitted to the final irrigation protocols. A new measure was realized and the difference between before and after the procedures was the dentin microhardness reduction. In sequence, the specimens were submitted to SEM analysis to verify the dentinal erosion. The Kruskal Wallis and Dunn tests (α = 5%) were used to compare the results. The dentin microhardness decreased for all final irrigation protocols. There was no significant difference between groups 2, 3, 4, and 5 (P > 0.05), but this groups presented significant dentin microhardness reduction than G1 (P < 0.05). In G2, occurred the highest incidence of dentinal erosion (P < 0.05). 17% EDTA, BioPure MTAD, SmearClear, and QMiX promoted significant dentin microhardness reduction. Dentinal tubules erosion was promoted by 17% EDTA.

Persistence of endodontic methacrylate-based cement residues on dentin adhesive surface treated with different chemical removal protocols.

The aim of this study was to evaluate the persistence of methacrylate-based cement residues on the dentin, after dentin surface cleaning with ethanol or acetone, with or without previous application of a dentin adhesive. Forty bovine crown fragments were obtained and the dentin surface was washed with 1.0 mL of 2.5% sodium hypochlorite (NaOCl), followed by 0.1 mL of 17% ethylenediaminetetraacetic acid application for 3 min, and final irrigation with 2.5% NaOCl. The specimens were air dried and resin-based cement was rubbed onto the dentine surface with a microbrush applicator. In 20 specimens, previously to cement, a dentin adhesive was applied in all surfaces. After 15 min, the surface was scrubbed with a cotton pellet and moistened with ethanol or acetone, compounding the following groups: G1-99.5% ethanol and G2-acetone, without previous use of dentin adhesive; G3-99.5% ethanol and G4-acetone, with previous use of dentin adhesive. The dentin surface was scrubbed until the cement residues could not be visually detected. Sections were then processed for scanning electron microscopy and evaluated at 500× magnification and scores were attributed to each image according to the area covered by residual sealer, and data were subjected to Kruskal-Wallis at 5% significance. The lower residue presence was observed in G3 (P = 0.005). All surface presented cement residues when acetone was used as cleaning solution (P = 0.0005). The cleaning solutions were unable to completely remove the cement residues from both surfaces. The ethanol used after previous application of the dentin adhesive promoted the lower presence of residues.

Estudo de lesões orais associadas a doenças dermatologicas / Study of oral lesions associated to dermatologic diseases

No presente trabalho, nos propusemos a avaliar a freqüência das lesões orais em pacientes portadores de doenças dermatológicas, visando despertar o cirurgião dentista para a necessidade de estabelecer um diagnóstico preciso. A amostra do nosso estudo constou de 101 pacientes procedentes do Serviço de Dermatologia do Hospital Universitário Onofre Lopes (HUOL) da UFRN com dermatopatologias diagnosticadas os quais foram examinados clinicamente com intuito de identificar alterações bucais. A idade dos pacientes variou entre 20 e 60 anos de idade, havendo predileção pelo sexo feminino (1.8:1). Do total de casos avaliados, 43 porcento eram de lúpus eritematoso, 35 porcento de líquen plano, 11 porcento de pênfigo vulgar, 8 porcento de eritema multiforme e 3 porcento eram do grupo penfigóide. As manifestações orais, em valores absolutos, foram mais freqüentes nos pacientes portadores de líquen plano (17) seguido pelo pênfigo (3), grupo penfigóide (2) e lúpus eritematoso (2). O líquen plano reticular foi a apresentação clínica mais comum e a mucosa jugal o sítio mais acometido. Os portadores de pênfigo e grupo penfigóide exibiram preferencialmente lesões de aspecto ulcerativo distribuídas na região de mucosa jugal e orofaringe, enquanto o lúpus eritematoso apresentava lesões circunscritas e eritematosas. Não foram observadas alterações bucais nos casos de eritema multiforme. De acordo com os resultados obtidos concluímos que o líquen plano foi a dermatopatologia mais prevalente em nosso estudo em relação à freqüência das alterações orais apresentadas, a partir da qual podemos inferir a necessidade do conhecimento do cirurgião dentista neste contexto e a importância do seu papel para que seja estabelecido um diagnóstico precoce e orientado o tratamento adequado com uma abordagem multidisciplinar