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ABSTRACT: To introduce a mapping method to characterize large dentin surfaces using digital microscopy and to discuss the advantages and possible applications of the method.
Twenty unerupted third molars were sectioned transversally exposing coronal dentin surfaces. The microscopic mosaic method was used to generate a large field image with the resolution necessary to measure characteristics of dentin tubules. The AxioVision 4.7 software was used to control a motorized optical microscope and the process of acquiring approximately 400 small images to generate each dentin mosaic. An image analysis routine measured the number of tubules (NT) and the ratio between the total area of tubules and the area of the mosaic - the area fraction (AF) - of each mosaic. An automatic procedure transformed the mosaic image into a color map, providing a direct visual representation of tubule density through colors. The dentin maps were used for a comparative qualitative analysis of tubule density distribution of each sample.
The results for NT (92450 to 196029 tubules/sample) and AF (4.12% to 11.10%) demonstrated a wide variation among dentin samples. The maps confirmed the microstructure variety, also revealing strong local variations in tubule density within each sample.
The mapping method was able to perform dentin morphology characterization and is a valuable tool for producing a baseline for dentin adhesion studies. The method could be also useful in determining the real contribution of dentin structures to the final adhesion quality.
The journal of adhesive dentistry 04/2012; 14(4):349-54. · 1.11 Impact Factor
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ABSTRACT: Matrix metalloproteinases (MMPs) and monocyte chemoattractants are key modulators of the biological mechanisms triggered in the periodontium by mechanical forces. The gingival crevicular fluid (GCF) provides a non-invasive method to assess longitudinally the release of inflammatory mediators during orthodontic tooth movement. The goal of this study was to examine the GCF levels of MMP-3, MMP-9, and MMP-13 and of the chemokines macrophage inflammatory protein (MIP)-1β, monocyte chemoattractant protein (MCP)-1, and regulated on activation normal T cells expressed and secreted (RANTES) at different time points during orthodontic tooth movement. Fourteen subjects (three males and 11 females, 18.8 ± 4.8 years of age; range from 12 to 28 years) had their maxillary canines retracted. Thirty-second GCF samples were collected from the tension and pressure sides 7 days prior to the activation of the orthodontic appliance, on the day of activation, and after 1 and 24 hours, and 14, 21, and 80 days of constant force application. The volume of GCF was measured and samples analysed using a multiplexed bead immunoassay for the content of the six target molecules. Differences in the mean GFC volumes and mean level for each analyte over time were assessed using the Friedman test, and differences between the tension and pressure sides at each time point with the Mann-Whitney test. The mean levels of the three MMPs changed significantly over time but only at the compression side (P < 0.05, Friedman test). The GCF levels of the three chemokines were not affected by the application of mechanical stress. The levels of MMPs in GCF at the pressure side are modulated by the application of orthodontic force.
The European Journal of Orthodontics 03/2011; 33(6):705-11. · 0.89 Impact Factor
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ABSTRACT: The purpose of this study was to research the presence of filamentous fungi in the root canals of teeth with pulp necrosis and periapical lesions and to perform the taxonomic study of the isolates.
Samples collected from 60 root canals with sterile absorbent paper points were inoculated in Sabouraud dextrose agar supplemented with chloramphenicol. The material was cultured from 7-14 days at room temperature to observe mycelial growth. Samples with growth were seeded in media specific for microculture (CYA agar, malt extract agar, or potato dextrose agar). Taxonomy was evaluated by macroscopic examination and optical microscopy.
Filamentous fungi were isolated in situ from 17 of 60 samples (28.3%). Considering the positive root canal isolates, the genus Aspergillus was isolated from 7 samples (41%); 4 species were identified: Aspergillus ustus, A. granulosus, A. niger, and A. sydowii. Emericella quadriluniata, sexual form of Aspergillus, was isolated from 1 sample. Penicillium species (Penicillium implicatum, P. micsynvisk, P. lividum, and P. citrionigrum) were isolated from 4 samples (24%). Fusarium species (Fusarium moniliforme and F. melanochorum) were isolated from 2 samples (12%). The species Aureobasidium pullulans, Exophiala jeanselmei, Eurotium amstelodame, and Cladosporium sphaerospermum were isolated from 1 sample each.
The root canals of teeth with pulp necrosis and periapical lesions might present positive culture for filamentous fungi.
Journal of endodontics 04/2010; 36(4):626-9. · 2.95 Impact Factor
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ABSTRACT: In the present study, the demineralizing ability of BioPure MTAD (Dentsply/Tulsa, Tulsa, OK), 17% EDTA, and 5% citric acid on radicular dentin was quantitatively and longitudinally analyzed. 3 mm thick disks were obtained at the root cervical third from 9 maxillary human molars, and a standardized smear layer was produced. Cosite images of the dentin surface were obtained after several cumulative demineralization times. Sixteen images were obtained in each dentin sample for each experimental time, at 1000x magnification. An image processing and analysis sequence measured sets of images, providing data of area fraction for thousands of tubules over time. Thus, it was possible to follow the demineralization phenomenon and quantitatively analyze the effect of the various substances. The nonparametric Kruskal-Wallis H-test was used to analyze the data. Based on the present results, it can be concluded that the demineralization kinetics promoted by both 5% CA and BioPure MTAD was significantly faster than by 17% EDTA.
Journal of Endodontics 12/2007; 33(11):1364-8. · 2.88 Impact Factor
