上颌第一恒磨牙根管形态的透明牙观察

目的:运用透明技术研究上颌第一恒磨牙根管形态。方法:收集离体上颌第一恒磨牙90颗保存在10%的福尔马林液中,将离体牙制作成透明标本,按Vertucci的标准对根管分类并记录根尖孔数目。结果:上颌第一恒磨牙均为三根牙。所有的腭根及绝大多数的远颊根(97.78%)为单根管。近颊根单根管率为22.22%,双根管率为73.34%,三根管率为4.44%,以Ⅱ型和Ⅳ型根管最为普遍。管间侧支在近颊根多见,侧支根管多见于根尖1/3。结论:上颌第一恒磨牙近颊根多根管率较高(77.78%),掌握其解剖形态对提高根管治疗成功率具有重要的临床意义。

Root and Canal Morphology of the Maxillary Permanent First Molars Using a Clearing Technique

Objective: To investigate the root and canal morphology of the maxillary permanent first molars using a clearing technique.Methods: A total of ninety extracted human maxillary first molars were used.The teeth were stored in 10% formalin solution after extraction.Then the specimens were studied using a clearing technique.The cleared teeth were examined under good lighting with a magnifying(×3),and examination of the root canal systems of the teeth was based on the vetucci's classification.The number of apical foramina were recorded.Results: All the maxillary first molars had three separated root.The majority of palatal(100%) and disto-buccal(97.78%) roots possessed one canal(typeⅠ).22.22% of mesiobuccal root had one canal.73.34% of mesiobuccal root had two canals and typeⅡ and Ⅳ were the most common.4.44% teeth had three root canals.Intercanal communications were most prevalent in mesiobuccal roots.Lateral canals were most prevalent in the apical third of the roots of the maxillary first molars.Conclusions: The maxillary first permanent molar has a high ratio of more than one root canal in mesiobuccal root(77.78%).