应用显微CT评估两种镍钛锉预备重度弯曲根管成形能力的实验研究(1)
[摘要]目的：使用显微CT(micro-computde tomographic imaging，Micro-CT)掃描成像系统，观察比较ProTaper Next(PTN)和Twisted Files Adaptive(TFA)预备下颌磨牙近中弯曲根管的成形能力。方法：20颗近期拔除的具有两个独立且呈25°～35°近中根管的下颌磨牙，采用两种机用根管锉系统进行根管预备，Micro-CT扫描并三维重建根备前后并成像，对以下参数分析：根管容积、表面积、根管偏移、根管/根宽度比和预备时间。结果：PTN平均偏移范围为0.038～0.174mm，TFA为0.079～0.197mm，在各水平评估的参数的统计学比较无显著性差异(P>0.05)。根管预备完成后，所有根管在观测水平的根管宽度都不超过根宽的35%。结论：应用Micro-CT系流评估，PTN和TFA在根管偏移和对中能力上具有相似结果，两种器械没有出现过度切削牙本质，降低了根折的风险。
[关键词]根管治疗；根管预备；Micro-CT；根管偏移；牙本质厚度
[中图分类号]R781.33 [文献标志码]A [文章编号]1008-6455(2019)01-0122-04
Experiment Research on Evaluating the Shapping Ability of Two Nickel-Titanium Instruments to Prepare Severely Curved Canals with Micro-CT
CHEN Xiao-yan，MA Yan，QIU Shen-cai，SHE Yu-xiu，WU Pei-ling
(Department of Stomatology， the Second Affiliated Hospital of Xinjiang Medical University， Urumqi 830068，Xinjiang，China)
Abstract： Objective ProTaper Next (PTN) and Twisted Files Adaptive (TFA) systems were used to prepare the proximal and medial curved root canals of mandibular molars. Micro-CT scans were used to compare the shapping ability. Methods A total of 20 with two independent 25°to 35°curved mesial root canals of extracted first mandibular molars were scanned using micro-CT imaging before and after root canal preparation with the 2 instrument systems.Three-dimensional reconstruction and analysis of image data before and after root preparation.The following parameters： root canal volume， surface area， root canal transportation， root canal/root width ratio， and preparation time. Results The ProTaper Next averaged transportation range was 0.038 to 0.174mm， and the TFA was 0.079 to 0.197mm. There was no statistically significant difference in the parameters evaluated at each level (P>0.05). After root canal preparation， the root canal width of all root canals at the observation level did not exceed 35% of the root width. Conclusion PTN and TFA have similar results in root canal transportation and center ratio. Both instruments do not have excessive cutting dentin and reduce the risk of root fracture.
Key words： root canal treatment ；root canal preparation；micro–computed tomographic imaging； root canal transportation；dentin thickness
根管预备是根管治疗的一个关键阶段，因为它不仅仅针对去除剩余的感染组织、微生物和碎屑，同时也为有效冲洗和根管封闭创造了先决条件。在牙髓治疗中，根管的解剖特征，如中重度弯曲度、裂纹、生理或病理矿化、根管宽度，均增加了根管预备程序的难度并要求医生更谨慎的专业技巧[1]。根管弯曲产生了一个复杂的因素，即无论选用哪种器械都会影响根管壁的成形和清洁的能力[2]。根管偏移为弯曲根管预备过程中的并发症之一，是指根管预备器械过度切削管壁，预备后的根管偏离根管中轴未维持原根管走向的现象[3]。在预备过程中，不同的镍钛器械、根尖预备大小等对根管壁的损伤程度也存在差异[4]。根管成形可能出现过度去除牙本质，当根部在受到来自根管充填、修复操作或咀嚼等进一步负荷时容易发生折裂[5-7]，有报道当根管宽度大于牙根宽度的35%时，根部折裂风险增加。本文通过Micro-CT评估两种镍钛锉预备重度弯曲根管的成形能力，旨在为临床应用提供参考。, http://www.100md.com(陈晓燕 马琰 邱申彩)
[关键词]根管治疗；根管预备；Micro-CT；根管偏移；牙本质厚度
[中图分类号]R781.33 [文献标志码]A [文章编号]1008-6455(2019)01-0122-04
Experiment Research on Evaluating the Shapping Ability of Two Nickel-Titanium Instruments to Prepare Severely Curved Canals with Micro-CT
CHEN Xiao-yan，MA Yan，QIU Shen-cai，SHE Yu-xiu，WU Pei-ling
(Department of Stomatology， the Second Affiliated Hospital of Xinjiang Medical University， Urumqi 830068，Xinjiang，China)
Abstract： Objective ProTaper Next (PTN) and Twisted Files Adaptive (TFA) systems were used to prepare the proximal and medial curved root canals of mandibular molars. Micro-CT scans were used to compare the shapping ability. Methods A total of 20 with two independent 25°to 35°curved mesial root canals of extracted first mandibular molars were scanned using micro-CT imaging before and after root canal preparation with the 2 instrument systems.Three-dimensional reconstruction and analysis of image data before and after root preparation.The following parameters： root canal volume， surface area， root canal transportation， root canal/root width ratio， and preparation time. Results The ProTaper Next averaged transportation range was 0.038 to 0.174mm， and the TFA was 0.079 to 0.197mm. There was no statistically significant difference in the parameters evaluated at each level (P>0.05). After root canal preparation， the root canal width of all root canals at the observation level did not exceed 35% of the root width. Conclusion PTN and TFA have similar results in root canal transportation and center ratio. Both instruments do not have excessive cutting dentin and reduce the risk of root fracture.
Key words： root canal treatment ；root canal preparation；micro–computed tomographic imaging； root canal transportation；dentin thickness
根管预备是根管治疗的一个关键阶段，因为它不仅仅针对去除剩余的感染组织、微生物和碎屑，同时也为有效冲洗和根管封闭创造了先决条件。在牙髓治疗中，根管的解剖特征，如中重度弯曲度、裂纹、生理或病理矿化、根管宽度，均增加了根管预备程序的难度并要求医生更谨慎的专业技巧[1]。根管弯曲产生了一个复杂的因素，即无论选用哪种器械都会影响根管壁的成形和清洁的能力[2]。根管偏移为弯曲根管预备过程中的并发症之一，是指根管预备器械过度切削管壁，预备后的根管偏离根管中轴未维持原根管走向的现象[3]。在预备过程中，不同的镍钛器械、根尖预备大小等对根管壁的损伤程度也存在差异[4]。根管成形可能出现过度去除牙本质，当根部在受到来自根管充填、修复操作或咀嚼等进一步负荷时容易发生折裂[5-7]，有报道当根管宽度大于牙根宽度的35%时，根部折裂风险增加。本文通过Micro-CT评估两种镍钛锉预备重度弯曲根管的成形能力，旨在为临床应用提供参考。, http://www.100md.com(陈晓燕 马琰 邱申彩)