Zuli Thaíse Ayres Bezerra, Guedes Orlando Aguirre, Gonçalves Gislaine Figueiredo Zarza Arguello, da Silva Júnior Aurélio Rosa, Borges Álvaro Henrique, Aranha Andreza Maria Fábio
Department of Oral Sciences, School of Dentistry, University of Cuiabá - UNIC, Cuiabá, MT, Brazil.
Department of Endodontics, School of Dentistry, Centro Universitário de Anápolis - UniEvangélica, Anápolis, GO, Brazil.
Restor Dent Endod. 2020 Oct 16;45(4):e53. doi: 10.5395/rde.2020.45.e53. eCollection 2020 Nov.
This study investigated the incidence of root dentin defects after the use of different post space preparation (PSP) drills.
Seventy-two bovine incisors were selected and obtained 14-mm-long root sections. Twelve roots served as controls with no intervention (G1). The 60 root canals remaining were instrumented using the crown-down technique with the ProTaper Next system and obturated using the lateral condensation technique. Specimens were randomly distributed into 5 groups ( = 12) according to the operative steps performed: G2, root canal instrumentation and filling (I+F); G3, I+F and PSP with Gates-Glidden drills; G4, I+F and PSP with Largo-Peeso reamers; G5, I+F and PSP with Exacto drill; and G6, I+F and PSP with WhitePost drill. Roots were sectioned at 3, 6, 9, and 12 mm from the apex, and digital images were captured. The presence of root dentin defects was recorded. Data were analyzed by the χ test, with < 0.05 considered to indicate statistical significance.
Root dentin defects were observed in 39.6% of the root sections. No defects were observed in G1. G5 had significantly more cracks and craze lines than G1, G2, and G3 ( < 0.05), and more fractures than G1, G2, G3, and G4 ( < 0.05). When all root sections were analyzed together, significantly more defects were observed at the 12-mm level than at the 3-mm level ( < 0.05).
PSP drills caused defects in the root dentin. Gates-Glidden drills caused fewer root defects than Largo-Peeso reamers and Exacto drills.
本研究调查了使用不同的桩道预备钻后根管牙本质缺陷的发生率。
选取72颗牛切牙，制备14毫米长的牙根段。12个牙根作为未干预的对照组（G1）。其余60个根管采用冠向下技术用ProTaper Next系统进行预备，并采用侧向加压技术进行充填。根据所执行的操作步骤将标本随机分为5组（每组n = 12）：G2，根管预备和充填（I+F）；G3，I+F并用Gates-Glidden钻进行桩道预备；G4，I+F并用Largo-Peeso扩孔钻进行桩道预备；G5，I+F并用Exacto钻进行桩道预备；G6，I+F并用WhitePost钻进行桩道预备。在距根尖3、6、9和12毫米处将牙根切片，并采集数字图像。记录根管牙本质缺陷的存在情况。数据采用χ检验进行分析，P < 0.05被认为具有统计学意义。
在39.6%的牙根切片中观察到根管牙本质缺陷。G1组未观察到缺陷。G5组的裂纹和裂隙线明显多于G1、G2和G3组（P < 0.05），骨折明显多于G1、G2、G3和G4组（P < 0.05）。当对所有牙根切片进行综合分析时，12毫米水平处观察到的缺陷明显多于3毫米水平处（P < 0.05）。
桩道预备钻会导致根管牙本质出现缺陷。Gates-Glidden钻导致的根管缺陷少于Largo-Peeso扩孔钻和Exacto钻。
