Aydin B, Köse T, Calişkan M K
Department of Restorative Dentistry and Endodontology, Ege University, Izmir, Turkey.
Int Endod J. 2009 Nov;42(11):1050-6. doi: 10.1111/j.1365-2591.2009.01624.x.
To compare the effectiveness of gutta-percha removal and the maintenance of canal anatomy when using the HERO 642 system or Hedström files (H-files) in mandibular molar teeth.
The root canals of 40 mandibular molar teeth were instrumented using H-files and filled with gutta-percha and sealer. After 1 year in storage, the roots were sectioned horizontally to provide apical, middle and coronal root thirds. Sections were photographed, and an individual muffle was produced for each tooth. Teeth were randomly divided into four groups (n = 10) and the gutta-percha removed using either the HERO 642 system or H-files, with or without solvent. Digital images of the root canals were then re-taken. Root thirds were inspected for lateral perforations, and the percentage of the residual canal filling was determined on postoperative images. Transportation and centring ratio were calculated using preoperative and postoperative images of the cross-sections of root thirds.
H-files groups were associated with less filling material than the HERO 642 system (H-files-HERO 642 P = 0.056, H-files-HERO 642+solvent P = 0.041, H-files + solvent-HERO 642 P = 0.018, H-files + solvent-HERO 642 + solvent P = 0.016). The percentage of residual filling material was similar in the apical thirds, and the contribution of solvent to canal debridement was not statistically significant (P > 0.05). Perforation occurred mesiobuccally in 48% of specimens in the apical sections of mesial roots. There were no significant differences for centring ratio, transportation and perforation rate between groups.
H-files left less gutta-percha overall; however, there was no difference in the apical third. The effect of solvent was not remarkable. Both instrument systems created a large number of perforations.
比较在处理下颌磨牙时，使用HERO 642系统或赫氏锉（H锉）去除牙胶和保持根管解剖结构的效果。
使用H锉对40颗下颌磨牙的根管进行预备，并用牙胶和封闭剂充填。储存1年后，将牙根水平切片，得到根尖、根中及根冠三分之一部分。对切片进行拍照，为每颗牙齿制作单独的模型。将牙齿随机分为四组（每组n = 10），使用HERO 642系统或H锉去除牙胶，使用或不使用溶剂。然后重新拍摄根管的数字图像。检查根三分之一部分是否有侧穿，并在术后图像上确定根管充填物残留的百分比。使用根三分之一横截面的术前和术后图像计算偏移率和定心率。
与HERO 642系统相比，H锉组残留的充填材料更少（H锉 - HERO 642，P = 0.056；H锉 - HERO 642 + 溶剂，P = 0.041；H锉 + 溶剂 - HERO 642，P = 0.018；H锉 + 溶剂 - HERO 642 + 溶剂，P = 0.016）。根尖三分之一处残留充填材料的百分比相似，溶剂对根管清创的作用无统计学意义（P > 0.05）。在近中牙根根尖段的标本中，48%在近中颊侧发生侧穿。各组之间在定心率、偏移率和侧穿率方面无显著差异。
总体而言，H锉残留的牙胶较少；然而，根尖三分之一处无差异。溶剂的效果不显著。两种器械系统均造成大量侧穿。
