上颌第二磨牙近颊根根管形态的研究

目的:运用透明牙技术研究上颌第二磨牙近颊根根管形态。方法:收集离体上颌第二磨牙70颗,先去除牙髓,根管内注入印度墨水,经10%硝酸脱钙,酒精梯度脱水,于99%水杨酸甲酯中透明,在放大镜下观察根管形态,按Vertucci标准对根管分类。结果:70颗上颌第二磨牙中67颗为三根牙,占95.71%。67颗三根牙的腭根和远颊根均为单根管,近颊根单根管率为55.22%。70颗上颌第二磨牙中,近颊第二根管(MB2)的发生率为42.86%,其根管类型以Ⅱ型(2-1)和Ⅳ型(2-2)为主。结论:上颌第二磨牙近颊根根管形态复杂,对其解剖形态熟练掌握,能够提高该牙根管治疗的成功率。

Root canal morphology of mesio-buccal root of maxillary second molars.

Objective： To investigate the root canal morphology of mesio-buccal root of maxillary second molars using a clearing technique and to provide a morphological basis in endodontic therapy. Method： A total of seventy extracted maxillary second molars were investigated. Following pulp tissue removal and canal system staining with Indian ink, the teeth were decalcified with 10 % nitric acid, dehydrated and cleared with 99 % methyl salicylate. Then the root canal configura- tion （Vertucci＇s classification） could be observed under good lighting with a magnifying. Result： 70 maxillary second molars had two different root forms, of which 67 molars had three separate roots （95.71%）. Among 67 molars, the majority of palatal （100 %）,disto-buceal （100 %） and mecio-buecal （55.22%） roots possessed one canal （type Ⅰ）. 42.86 % of 70 molars had MB2 and type Ⅱ（2-1） and type Ⅳ （2-2） were the most common. Conclusion：The root canal morphology of maxillary second molars especially the mesio-buccal root.presents a complicated canal system. It is hepful to increase the success of endodontic therapy based on the clear root canal morphology of maxillary second molars.