Rashed Bayan, Iino Yoshiko, Ebihara Arata, Okiji Takashi
Department of Pulp Biology and Endodontics, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University (TMDU), Tokyo, Japan.
King Abdul-Aziz Airbase Hospital, Dhahran, Saudi Arabia.
Scanning. 2019 Dec 30;2019:5240430. doi: 10.1155/2019/5240430. eCollection 2019.
This study is aimed at determining (1) the effect of root-end resection, ultrasonic root-end preparation, and root-end filling on the incidence of crack formation and propagation by using a digital microscope (DM) and optical coherence tomography (OCT) and (2) the performance of OCT on the detection of cracks by comparing with microcomputed tomography (micro-CT) as a reference standard.
Thirty extracted lower incisors were endodontically treated and subjected to root-end resection and ultrasonic root-end cavity preparation. Then, the teeth were divided into three groups ( = 10, each), and the root-end cavity was either left unfilled or filled with mineral trioxide aggregate (MTA) or super-EBA. The resected surface was observed with OCT and DM after the root-end resection, ultrasonic root-end preparation, and root-end filling, and the frequency of incomplete and complete cracks were recorded. The observation was repeated after two weeks, one month, and two months, and micro-CT scans after two months were taken as the gold standard.
The DM results show dentinal crack formation in 47% of the samples following root-end resection and in 87% following ultrasonic preparation. After the ultrasonic preparation, no existing crack propagated to a complete crack, but new cracks were formed. MTA and super-EBA had no effect on crack formation. The Spearman correlation coefficient between OCT and DM was 0.186 (very weak correlation; = 0.015). Sensitivity and specificity in comparison to micro-CT were 0.50 and 0.55 in OCT and 1.00 and 0.35 in DM, respectively. McNemar's test showed a significant difference between OCT and DM ( < 0.05).
Apical resection and ultrasonic preparation could form dentinal cracks. OCT and DM showed different detection frequencies of cracks with very weak correlation. DM showed superior sensitivity compared with OCT.
本研究旨在确定：（1）使用数字显微镜（DM）和光学相干断层扫描（OCT）观察根尖切除术、超声根尖预备和根尖充填对裂纹形成和扩展发生率的影响；（2）通过与作为参考标准的微型计算机断层扫描（micro-CT）比较，评估OCT检测裂纹的性能。
选取30颗拔除的下颌切牙进行根管治疗，然后进行根尖切除术和超声根尖窝洞预备。之后，将牙齿分为三组（每组n = 10），根尖窝洞分别不充填、用三氧化矿物凝聚体（MTA）或超级EBA充填。在根尖切除、超声根尖预备和根尖充填后，用OCT和DM观察切除表面，记录不完全裂纹和完全裂纹的发生率。在两周、一个月和两个月后重复观察，以两个月后的micro-CT扫描作为金标准。
DM结果显示，根尖切除后47%的样本出现牙本质裂纹形成，超声预备后87%的样本出现牙本质裂纹形成。超声预备后，现有的裂纹没有扩展为完全裂纹，但形成了新的裂纹。MTA和超级EBA对裂纹形成没有影响。OCT和DM之间的Spearman相关系数为0.186（相关性非常弱；P = 0.015）。与micro-CT相比，OCT的敏感性和特异性分别为0.50和0.55，DM的敏感性和特异性分别为1.00和0.35。McNemar检验显示OCT和DM之间存在显著差异（P < 0.05）。
根尖切除术和超声预备可形成牙本质裂纹。OCT和DM显示出不同的裂纹检测频率，相关性非常弱。与OCT相比，DM显示出更高的敏感性。
