UNASSIGNED: Thirty-six Vertucci\'s type III mandibular incisors were evaluated by micro-computed tomography (micro-CT) and divided into 3 groups (n = 12) according to the root canal preparation protocol (HyFlex CM [HCM], HyFlex EDM [HEDM], and Sequence Rotary File [SRF]). The teeth were scanned before and after performing 0.25 mm and 0.40 mm apical diameter preparations. The canal volume, dentin thickness, percentage of accumulated debris and untouched canal areas, transportation, and centering ability were measured. The data were statistically analyzed by ANOVA, Tukey, Kruskal-Wallis, and Dunn tests (P < 0.05).
UNASSIGNED: The volume increase was more evident in the apical third. After 0.40 mm preparation, the SRF system provided a higher reduction (P < 0.05) in dentin thickness on the buccal surface 1 mm from the apex. There was higher canal transportation in the bucco-lingual direction. The 0.40 mm apical preparation reduced the percentage of untouched canal areas. The apical third had the highest percentage of untouched canal areas. The cervical third had the lowest volume of accumulated debris.
UNASSIGNED: Increasing the apical preparation to a diameter of 0.40 mm with the HCM, HEDM, and SRF systems in Vertucci\'s type III root canals of mandibular incisors proved to be safe and effective, reducing untouched canal areas.
UNASSIGNED: Root flattening can be intense to the point of generating a root canal bifurcation. Despite the decrease in the root canal diameter, a greater enlargement of the apical region is necessary and safe.
■通过显微计算机断层扫描(micro-CT)评估了36个Vertucci的III型下颌切牙,并根据根管准备方案将其分为3组(n=12)(HyFlexCM[HCM],HyFlex电火花[HEDM],和序列旋转文件[SRF])。在进行0.25mm和0.40mm根尖直径准备之前和之后扫描牙齿。运河容积,牙本质厚度,堆积的碎片和未触及的运河面积的百分比,交通运输,和对中能力进行了测量。数据进行方差分析,Tukey,Kruskal-Wallis,Dunn检验(P<0.05)。
■体积增加在顶端第三区更明显。在0.40mm准备之后,SRF系统在距顶点1mm的颊表面上提供了更高的牙本质厚度减少(P<0.05)。在颊舌方向上有较高的运河运输。0.40毫米的根尖准备减少了未触及的根管面积的百分比。根尖三分之一的未受影响的运河面积百分比最高。宫颈三分之一的积聚碎片体积最低。
■用HCM将根尖准备增加到0.40mm的直径,HEDM,VertucciIII型下颌切牙根管的SRF系统被证明是安全有效的,减少未触及的运河区域。
■根部展平可能强烈到产生根管分叉的程度。尽管根管直径减小,根尖区域的扩大是必要和安全的。