Madarati Ahmad A, Qualtrough Alison J E, Watts David C
Department of Endodontic, Aleppo University, Syria.
J Endod. 2009 Jan;35(1):125-8. doi: 10.1016/j.joen.2008.10.005.
This in vitro study aimed to investigate the effect of ultrasonic removal of endodontic fractured files on tooth structure. Fifty-three canine roots were cleaned and weighed. They were scanned by a microcomputed tomography scanner producing two-dimensional images that were reconstructed into two-dimensional slices, and, finally, the canal volume was measured. In a control group, canals were prepared to F5-size ProTaper (Dentsply Ltd, Surrey, UK). In three experimental groups, F5-fractured files were ultrasonically removed from three root canal locations: coronal, middle, and apical. All roots were reweighed and rescanned. Reconstruction and analysis were performed to remeasure the canal volume. The differences in root mass (weight) and canal volume between before and after treatment were calculated. The highest change increase in canal volume was found when fractured files were removed from the apical part followed by middle and coronal. A positive correlation existed between canal volume and root mass changes. Microcomputed tomography scanning can reliably determine changes in canal volume resulting from fractured-file removal.
这项体外研究旨在探讨超声去除根管内折断锉对牙齿结构的影响。对53颗犬牙根进行清洁并称重。用微型计算机断层扫描仪对其进行扫描，生成二维图像并重建为二维切片，最后测量根管容积。在对照组中，将根管预备至F5尺寸的ProTaper（登士柏有限公司，英国萨里）。在三个实验组中，从三个根管位置（冠部、中部和根尖部）超声去除F5折断锉。所有牙根再次称重并重新扫描。进行重建和分析以重新测量根管容积。计算治疗前后牙根质量（重量）和根管容积的差异。当从根尖部去除折断锉时，根管容积增加的变化最大，其次是中部和冠部。根管容积变化与牙根质量变化之间存在正相关。微型计算机断层扫描能够可靠地确定去除折断锉后根管容积的变化。
