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Medical Sciences	100%

Selected Abstracts

Percentage of filled canal area in mandibular molars after conventional root-canal instrumentation and after a noninstrumentation technique (NIT)

INTERNATIONAL ENDODONTIC JOURNAL, Issue 9 2003
C. N. Ardila
Abstract Aim, To compare the percentage of filled canal area in mandibular molar roots after using conventional root-canal hand instrumentation or after a noninstrumentation technique (NIT). Methodology, Forty mandibular molars were used shortly after extraction. The root canals of 20 molars in the manual group were conventionally prepared using hand instruments and then filled with warm vertical compaction of gutta-percha. The 20 teeth in the second group were cleaned and obturated by NIT. In each case, the entire molar, including the crown and the roots, was embedded in an acrylic resin cylinder before NIT. Horizontal sections were cut at 2, 4, 6 and 8 mm from the apex. Images of the sections were taken using a microscope at ×40 magnification and a digital camera; the images were scanned as Tagged Image File Format (TIFF) images into a PC. The cross-sectional area of the canal with the filling materials was measured using an image analysis programme. The percentage of filled area was calculated. The difference in the percentage of filled canal area between the two groups was analysed using a Student's t -test. Results, At all levels, 93,100% of the canal area was filled in both groups. No significant difference was found between the manual technique and the NIT technique at any level (P > 0.05). Conclusions, Within the limitations of this study, following the cleaning and filling of root canals using NIT, the percentage of filled root canal was similar to that using warm vertical compaction of gutta-percha after conventional root-canal instrumentation. [source]

Application of a digital technique in evaluating the reliability of shade guides

JOURNAL OF ORAL REHABILITATION, Issue 5 2004
E. Cal
summary, There appears to be a need for a reliable method for quantification of tooth colour and analysis of shade. Therefore, the primary objective of this study was to show the applicability of graphic software in colour analysis and secondly to investigate the reliability of commercial shade guides produced by the same manufacturer, using this digital technique. After confirming the reliability and reproducibility of the digital method by using self-assessed coloured images, three shade guides of the same manufacturer were photographed in daylight and in studio environments with a digital camera and saved in tagged image file format (TIFF) format. Colour analysis of each photograph was performed using the Adobe Photoshop 4·0 graphic program. Luminosity, and red, green, blue (L and RGB) values of each shade tab of each shade guide were measured and the data were subjected to statistical analysis using the repeated measure Anova test. The L and RGB values of the images taken in daylight differed significantly from those of the images taken in studio environment (P < 0·05). In both environments, the luminosity and red values of the shade tabs were significantly different from each other (P < 0·05). It was concluded that, when the environmental conditions were kept constant, the Adobe Photoshop 4·0 colour analysis program could be used to analyse the colour of images. On the other hand, the results revealed that the accuracy of shade tabs widely being used in colour matching should be readdressed. [source]

Embedding 3D models of biological specimens in PDF publications

MICROSCOPY RESEARCH AND TECHNIQUE, Issue 11 2008
Bernhard Ruthensteiner
Abstract By providing two examples, the option for embedding 3D models in electronic versions of life science publications is presented. These examples, presumably representing the first such models published, are developmental stages of an evertebrate (Patella caerulea, Mollusca) and a vertebrate species (Psetta maxima, Teleostei) obtained from histological section series reconstruction processed with the software package Amira. These surface rendering models are particularly suitable for a PDF file because they can easily be transformed to a file format required and components may be conveniently combined and hierarchically arranged. All methodological steps starting from specimen preparation until embedding of resulting models in PDF files with emphasis on conversion of Amira data to the appropriate 3D file format are explained. Usability of 3D models in PDF documents is exemplified and advantages over 2D illustrations are discussed, including better explanation capabilities for spatial arrangements, higher information contents, and limiting options for disguising results by authors. Possibilities for additional applications reaching far beyond the examples presented are suggested. Problems such as long-term compatibility of file format and hardware plus software, editing and embedding of files, file size and differences in information contents between printed and electronic version will likely be overcome by technical development and increasing tendency toward electronic at the cost of printed publications. Since 3D visualization plays an increasing role in manifold disciplines of science and appropriate tools for the popular PDF format are readily available, we propose routine application of this way of illustration in electronic life science papers. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc. [source]