Usta Sıla Nur, Tekkanat Hilal, Sağlam Yiğitcan, Aydin Cumhur
Department of Endodontics, Gulhane Faculty of Dentistry, University of Health Sciences, Ankara, Turkey.
J Dent Res Dent Clin Dent Prospects. 2025 Mar 31;19(1):23-28. doi: 10.34172/joddd.025.42125. eCollection 2025 Mar.
This study evaluated the influence of the combined effects of remaining dentin walls and mechanical instrumentation with taper sizes of 0.04 and 0.06 on the fracture resistance of endodontically treated mandibular premolars.
Seventy single-canal mandibular premolar teeth with similar dimensions were selected and divided into one control group and three main experimental groups: control group: intact teeth, group 1: four remaining walls, group 2: three remaining walls, and group 3: two remaining walls. Each group was further divided into two subgroups in terms of preparation size (0.06 or 0.04 taper). The teeth were restored with composite resin after creating restorative models and performing endodontic treatments. The fracture resistance of teeth was measured by the push-out test. Data were analyzed using two-way ANOVA and post hoc tests and the square of Spearman's linear coefficient (<0.05).
The control group exhibited the highest fracture resistance compared to the experimental groups (<0.05). Regardless of the taper size, group 3 showed the lowest fracture resistance values compared to groups 1 and 2 (<0.05). Preparation sizes similarly affected the fracture strength of teeth (>0.05). A significant positive association was found between the remaining dentin walls and fracture resistance (<0.05).
This study emphasized the importance of preserving coronal dentin for fracture resistance in endodontically treated teeth (ETTs). Conservative instrumentation did not provide any advantages over traditional preparation in increasing fracture resistance.
本研究评估了剩余牙本质壁以及锥度尺寸为0.04和0.06的机械预备对经根管治疗的下颌前磨牙抗折性能的联合影响。
选取70颗尺寸相似的单根管下颌前磨牙，分为1个对照组和3个主要实验组：对照组：完整牙齿；第1组：保留4个壁；第2组：保留3个壁；第3组：保留2个壁。每组根据预备尺寸（0.06或0.04锥度）进一步分为两个亚组。制作修复模型并进行根管治疗后，用复合树脂修复牙齿。通过推出试验测量牙齿的抗折性能。使用双向方差分析、事后检验和Spearman线性系数平方（<0.05）分析数据。
与实验组相比，对照组表现出最高的抗折性能（<0.05）。无论锥度大小，与第1组和第2组相比，第3组的抗折性能值最低（<0.05）。预备尺寸同样影响牙齿的抗折强度（>0.05）。剩余牙本质壁与抗折性能之间存在显著正相关（<0.05）。
本研究强调了保留冠部牙本质对经根管治疗牙齿抗折性能的重要性。在增加抗折性能方面，保守预备与传统预备相比没有任何优势。
