College of Dentistry, King Saud University, Riyadh, Saudi Arabia.
J Appl Oral Sci. 2012 Nov-Dec;20(6):655-60. doi: 10.1590/s1678-77572012000600011.
The aim of this study was to quantify the surface area, volume and specific surface area of endodontic files employing quantitative X-ray micro computed tomography (mXCT).
Three sets (six files each) of the Flex-Master Ni-Ti system (Nº 20, 25 and 30, taper .04) were utilized in this study. The files were scanned by mXCT. The surface area and volume of all files were determined from the cutting tip up to 16 mm. The data from the surface area, volume and specific area were statistically evaluated using the one-way ANOVA and SNK multiple comparison tests at α=0.05, employing the file size as a discriminating variable. The correlation between the surface area and volume with nominal ISO sizes were tested employing linear regression analysis.
The surface area and volume of Nº 30 files showed the highest value followed by Nº 25 and Nº 20 and the differences were statistically significant. The Nº 20 files showed a significantly higher specific surface area compared to Nº 25 and Nº 30. The increase in surface and volume towards higher file sizes follows a linear relationship with the nominal ISO sizes (r²=0.930 for surface area and r²=0.974 for volume respectively). Results indicated that the surface area and volume demonstrated an almost linear increase while the specific surface area exhibited an abrupt decrease towards higher sizes.
This study demonstrates that mXCT can be effectively applied to discriminate very small differences in the geometrical features of endodontic micro-instruments, while providing quantitative information for their geometrical properties.
本研究旨在通过定量 X 射线微计算机断层扫描（mXCT）来量化根管锉的表面积、体积和比表面积。
本研究使用了 Flex-Master Ni-Ti 系统（N° 20、25 和 30，锥度为.04）的三组（每组 6 根）文件。通过 mXCT 对文件进行扫描。从切削尖端到 16mm 处，确定所有文件的表面积和体积。使用单向方差分析和 SNK 多重比较检验，以文件尺寸为判别变量，对表面积、体积和比表面积数据进行统计学评估，α=0.05。使用线性回归分析测试表面积和体积与名义 ISO 尺寸之间的相关性。
N° 30 文件的表面积和体积显示出最高值，其次是 N° 25 和 N° 20，且差异具有统计学意义。N° 20 文件的比表面积明显高于 N° 25 和 N° 30。随着文件尺寸的增加，表面积和体积呈线性增加，与名义 ISO 尺寸呈线性关系（表面积的 r²=0.930，体积的 r²=0.974）。结果表明，表面积和体积呈线性增加，而比表面积则呈急剧下降趋势。
本研究表明，mXCT 可有效用于区分根管锉几何特征的微小差异，并为其几何特性提供定量信息。
