Mangal Shivani, Mathew Sylvia, Sreenivasa Murthy B V, Nagaraja Shruthi, Dinesh K, Ramesh Poornima
Department of Conservative Dentistry and Endodontics, Faculty of Dental Sciences, Ramaiah University of Applied Sciences, Bengaluru, Karnataka, India.
J Conserv Dent. 2018 Jan-Feb;21(1):63-67. doi: 10.4103/JCD.JCD_390_16.
Intraradicular procedures remove radicular dentin and jeopardizing longevity of a tooth. Traditional methods used to determine the remaining dentin thickness (RDT) have limitations.
The aim is to evaluate, using cone-beam computed tomography (CBCT), RDT following rotary instrumentation and post space preparation in buccal and palatal roots of maxillary first premolars.
Twenty-three maxillary first premolars with two roots were selected. CBCT images were taken preoperatively, after instrumentation and Parapost 3 and 4 preparation (CBCT 1, 2, 3, and 4). RDT was measured 5 mm above apex, 1 mm below furcation, and 1 mm above furcation (Levels 1, 2, and 3). Data were analyzed using ANOVA and Tukey's test ( = 0.05).
Rotary instrumentation and post space preparation reduced RDT in all walls of buccal and palatal roots. Post space preparation with Parapost 3 and 4 reduced RDT in the palatal wall of buccal root to <1 mm and Parapost 4 reduced all walls to 1 mm of dentin.
Post space preparation in maxillary first premolars should be performed cautiously. It is safer to place a post in the palatal root of this tooth and limit preparation to Parapost 3.
根管内操作会去除根管牙本质并危及牙齿的寿命。用于确定剩余牙本质厚度（RDT）的传统方法存在局限性。
旨在使用锥形束计算机断层扫描（CBCT）评估上颌第一前磨牙颊根和腭根在旋转器械预备和桩道预备后的RDT。
选择23颗有两个牙根的上颌第一前磨牙。在术前、器械预备后以及使用Parapost 3和Parapost 4进行桩道预备后（CBCT 1、2、3和4）拍摄CBCT图像。在根尖上方5 mm、根分叉下方1 mm和根分叉上方1 mm处（水平1、2和3）测量RDT。使用方差分析和Tukey检验（α = 0.05）分析数据。
旋转器械预备和桩道预备降低了颊根和腭根所有壁的RDT。使用Parapost 3和Parapost 4进行桩道预备使颊根腭侧壁的RDT降至<1 mm，Parapost 4使所有壁的牙本质厚度降至1 mm。
上颌第一前磨牙的桩道预备应谨慎进行。将桩放置在该牙的腭根并将预备限制在Parapost 3更安全。
