Hilaly Eid Ghada El, Wanees Amin Suzan Abdul
Department of Endodontics, Faculty of Oral and Dental Medicine, Cairo University, Cairo, Egypt.
Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 2011 Nov;112(5):688-95. doi: 10.1016/j.tripleo.2011.05.007. Epub 2011 Sep 8.
The objective of this study was to compare the shaping ability of manual H-files, rotary nickel-titanium ProTaper system, and reciprocating SafeSiders in long oval-shaped root canals.
The roots of 45 human premolars were sectioned at 2 levels in the middle third and reassembled using a 3-piece metal mold. Pre- and postinstrumentation cross-sectional images were superimposed and evaluated in terms of change in buccolingual-to-mesiodistal canal ratio, maximum buccolingual and mesiodistal canal dimensions, and cross-sectional areas. Ratios of touched canal wall and canal outline with more than 200 μm dentin removal to the original canal perimeter were also calculated.
The buccolingual-to-mesiodistal ratio decreased after instrumentation with no difference among techniques (P > .05). The change in the buccolingual dimension was significantly less for SafeSiders compared with H-files and ProTaper (P < .05). The change in mesiodistal dimension was significantly less with SafeSiders compared with H-files only (P < .05). The change in area, in descending order, was as follows: H-files > ProTaper > SafeSiders (P < .05). The ratio of touched canal outline was highest with H-files, compared with ProTaper and SafeSiders (P < .05), and H-files recorded the highest ratio of canal outline with more than 200 μm of dentin thickness removal (P < .05).
None of the 3 instrumentation techniques completely prepared the oval root canal. Manual and rotary NiTi instrumentation may perform better than reciprocating SafeSider instrumentation in shaping oval canals.
本研究的目的是比较手动H锉、旋转镍钛ProTaper系统和往复式SafeSiders在长椭圆形根管中的根管预备能力。
将45颗人前磨牙的牙根在中1/3处分为2个水平，并使用三件式金属模具重新组装。将器械操作前后的横截面图像进行叠加，并根据颊舌径与近远中径的根管比率变化、最大颊舌径和近远中径根管尺寸以及横截面积进行评估。还计算了器械操作后根管壁与根管轮廓的接触比率，即去除超过200μm牙本质后的接触比率与原始根管周长的比值。
器械操作后颊舌径与近远中径的比率降低，各技术之间无差异（P>.05）。与H锉和ProTaper相比，SafeSiders在颊舌径上的变化明显更小（P<.05）。与仅H锉相比，SafeSiders在近远中径上的变化明显更小（P<.05）。面积变化由大到小依次为：H锉>ProTaper>SafeSiders（P<.05）。与ProTaper和SafeSiders相比，H锉的根管轮廓接触比率最高（P<.05），且H锉记录的去除牙本质厚度超过200μm的根管轮廓比率最高（P<.05）。
三种器械操作技术均未完全预备椭圆形根管。在椭圆形根管预备方面，手动和旋转镍钛器械操作可能比往复式SafeSider器械操作效果更好。
