van der Sluis L W M, Wu M-K, Wesselink P R
Department of Cariology Endodontology Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.
Int Endod J. 2005 Sep;38(9):593-6. doi: 10.1111/j.1365-2591.2005.00921.x.
To compare the efficacy of a smooth wire with a conventional K-file, in removing dentine debris from grooves in root canals made in resin blocks, during ultrasonic irrigation.
Each resin block containing a standard simulated canal was split longitudinally through the canal, forming two halves. In one canal wall, a standard groove 4 mm in length, 0.2 mm in width and 0.5 mm in depth was cut 2-6 mm from the apical end of the canal, to simulate uninstrumented canal extensions. Each groove was filled with fresh dentine debris mixed with 2% NaOCl to simulate a situation when dentine debris accumulates in uninstrumented canal extensions. Each canal was reassembled by joining the two halves of the resin block by means of wires and sticky wax. In each canal ultrasonic irrigation was performed for 3 min using 2% NaOCl as irrigant. In one group (n = 20) a conventional K-file size 15 was used. In the other group (n = 20) a smooth wire was used which had the same length and diameter as the size 15 K-file. Before and after irrigation, images of each half of the canal with a groove were taken, using a microscope and a digital camera, after which they were scanned into a PC as TIFF images. The quantity of dentine debris in the groove was evaluated using a scoring system: the higher the score, the larger the amount of debris remaining. The score data were analysed by means of the Mann-Whitney U-test.
After ultrasonic irrigation, the debris was completely removed from the groove in 35 canals (87.5%), and there was no significant difference between the groups (P = 0.429).
Using a smooth wire during ultrasonic irrigation is as effective as a size 15 K-file in removal of artificially placed dentine debris in grooves in simulated root canals in resin blocks.
比较在超声冲洗过程中，光滑金属丝与传统K锉从树脂块中制备的根管凹槽清除牙本质碎屑的效果。
将每个含有标准模拟根管的树脂块沿根管纵向劈开，分成两半。在一个根管壁上，从根管根尖端2 - 6毫米处切割一个长4毫米、宽0.2毫米、深0.5毫米的标准凹槽，以模拟未预备的根管延伸段。每个凹槽填充新鲜牙本质碎屑并与2%次氯酸钠混合，以模拟牙本质碎屑积聚在未预备的根管延伸段的情况。通过金属丝和粘性蜡将树脂块的两半重新连接起来，使每个根管重新组合。在每个根管中，使用2%次氯酸钠作为冲洗剂进行3分钟的超声冲洗。一组（n = 20）使用传统的15号K锉。另一组（n = 20）使用与15号K锉长度和直径相同的光滑金属丝。冲洗前后，使用显微镜和数码相机拍摄带有凹槽的根管每一半的图像，然后将其作为TIFF图像扫描到个人电脑中。使用评分系统评估凹槽中牙本质碎屑的量：分数越高，残留的碎屑量越大。分数数据采用曼-惠特尼U检验进行分析。
超声冲洗后，35个根管（87.5%）凹槽中的碎屑被完全清除，两组之间无显著差异（P = 0.429）。
在超声冲洗过程中使用光滑金属丝与15号K锉在清除树脂块模拟根管凹槽中人工放置的牙本质碎屑方面效果相同。
