C형 근관을 가진 하악 제2대구치 주근단공의 주사전자현미경적 관찰

Abstract

하악 제2대구치는 임상에서 근관치료시 많은 실패율을 보이고 있다. 특히, C형 근관을 갖는 경우에는 치근단부 해부학적 형태의 복잡성으로 인해 근관 내 기구조작 및 이상적인 충전이 어려워 실패의 많은 빈도를 보이고 있다. 본 연구에서는 해부학적 형태를 관찰하기가 어려운 C 형 근관을 가진 하악 제2대구치의 근단부에 위치한 주근단공의 크기와 변위방향, 그리고 주근단공의 형태를 주사전자현미경을 이용하여 조사하였다. C형 근관을 가진 하악 제2대구치의 주근단공의 가장 넓은부위와 좁은부의의 평균 폭경은 각각 0.372mm, 0.176mm로 다른 치아에 비해 더 큰 폭경을 갖고 근첨에서 원심협측 방향으로 편향됨이 관찰되었다. 따라서 임상가들은 C형 근관의 초기근관장 파일의 설졍시 좀 더 큰 크기의 파일을 사용해야 하며 기구 조작 시 측방천공의 가능성을 염두에 두고 주의를 기울여야 한다. 또한 대부분 C형 근관의 주근단공의 형태는 난원형으로 근관의 적절한 폐쇄를 위해 근관성형과 충전시 많은 주의가 필요할 것으로 사료된다.|The complexicity of C-shaped canals prevents these canals from being cleaned, shaped, and obturated effectively during root canal therapy. Therefore, a thorough knowledge of the root canal anatomy, especially of the apex area, may have an important effect on the prognosis of endodontic therapy. The aim of this study was to examine the apical region of C-shaped canal systems in mandibular second molars with the use of a scanning electron microscope (SEM) to determine size, direction of deviation and shape of main apical foramen. Thirteen mandibular molars with C-shaped root were selected. After coronal section, the molars were stored into the solution of 5% sodium hypochlorite for 24 hours, and the roots were cut at 5 mm coronally from the apexes. Samples were prepared for SEM observation. During examination, the size and position of every foramen larger than 10 ㎛ was recorded. Foramina larger than 100 ㎛ were characterized as main formina (MF) and formaina smaller than 100 ㎛ as accessory foramina (AF). The results were as follows : 1. The mean value for the longest and the shortest diameter of the main foramen were found to be 0.176 mm and 0.375 mm. 2. Main foramen was not found to coincide with the main axis of the root. Direction of deviation of main foramen from apex was distobuccal. 3. Shape of the main foramen was oval. In conclusion, the apical anatomy of C-shaped root canal systems is extremely complex with many anatomical varieties. Diameter of main foramen was observed to be larger diameter compared to other teeth and all canals were deviated from tooth axis. Therefore, the clinicians should be care of the possibilities of overinstrumentation, and as for the C-shaped root canal, use of larger files can be recommended to establish initial apical file (IAF). And the shape of most C-shaped root canal is oval, so that special attention will be needed during canal preparation and canal filling.