Department of Endodontics, College of Dentistry, University of Tanta, Egypt.
J Adv Res. 2013 Mar;4(2):123-8. doi: 10.1016/j.jare.2012.03.002. Epub 2012 Apr 12.
The purpose of this study was to investigate canal configuration of mandibular first premolars in an Egyptian population. Two hundred fifty human extracted mandibular first premolars were collected from Egyptian patients and a small hole in the center of the occlusal surface of each tooth was made perforating the roof of the pulp chamber. Teeth were decalcified by immersing in nitric acid and dehydrated in ascending concentrations of ethyl alcohol. A waterproof black ink was passively injected from the occlusal hole into pulp system and stained teeth were immersed in methyl salicylate solution for clearing. Standardized pictures of the cleared teeth were obtained and anatomical features of the root canal were observed. The average length of the mandibular first premolar teeth was 22.48 ± 1.74 mm, one-rooted teeth were 96.8% and the two-rooted were 3.2%. Vertucci Type I canal configuration represented the highest percentage (61.2%) followed by Type V (16.4%), Type IV (13.2%), Type II (5.6%) and Type III (2.8%). Vertucci Type VI canal configuration represented the lowest percentage (0.4%) and a complex configuration was found in one tooth. Accessory canals were detected in 22.8% and inter-canal connections were observed in 24.8% while 54% showed apical delta. Such knowledge is clinically useful for localization and negotiation of canals of mandibular first premolar, as well as their subsequent management in Egyptian population.
本研究旨在调查埃及人群下颌第一前磨牙的根管形态。从埃及患者中收集了 250 个人工离体下颌第一前磨牙，并在每个牙齿的咬合面中心钻一个小孔，穿透牙髓腔的顶部。牙齿用硝酸浸泡进行脱钙，然后用递增浓度的乙醇进行脱水。将防水黑色墨水从咬合孔被动注入牙髓系统，然后将染色的牙齿浸入水杨酸甲酯溶液中进行透明化。获得了牙齿透明化的标准图片，并观察了根管的解剖特征。下颌第一前磨牙的平均长度为 22.48 ± 1.74 毫米，单根牙占 96.8%，双根牙占 3.2%。维氏Ⅰ型根管形态占比最高（61.2%），其次是维氏Ⅴ型（16.4%）、维氏Ⅳ型（13.2%）、维氏Ⅱ型（5.6%）和维氏Ⅲ型（2.8%）。维氏Ⅵ型根管形态占比最低（0.4%），且有一颗牙呈现复杂根管形态。发现 22.8%的牙齿存在副根管，24.8%的牙齿存在根管间连接，而 54%的牙齿显示根尖三角。这些知识对埃及人群下颌第一前磨牙根管的定位和预备以及后续处理具有重要的临床意义。
