Agarwal Anand, Deore Rahul B, Rudagi Kavitarani, Nanda Zinnie, Baig Mirza Osman, Fareez Md Adil
Department of Conservative Dentistry and Endodontics A.C.P.M. Dental College, Dhule, Maharashtra, India.
Department of Conservative Dentistry and Endodontics A.C.P.M. Dental College, Dhule, Maharashtra, India, Phone: +919673390777, e-mail:
J Contemp Dent Pract. 2017 Sep 1;18(9):790-794. doi: 10.5005/jp-journals-10024-2128.
The aim of this study was (i) to evaluate the formation of air bubbles in the apical region of root canal (apical vapor lock) during syringe irrigation, using cone beam computed tomography (CBCT) and (ii) comparative evaluation of the elimination of an established vapor lock by EndoActivator, ultrasonics, and manual dynamic agitation (MDA), using CBCT.
A total of 60 extracted human single-rooted teeth were equally divided into three groups of 20 teeth each. The samples were decoronated 17 mm from the apex, cleaned, and shaped to size F4 Protaper using 3% sodium hypochlorite. Samples were irrigated with 3% sodium hypochlorite + cesium chloride radiopaque dye, and preoperative CBCT images were obtained. After formation of apical vapor lock in the scanned teeth, EndoActivator (group I), passive ultrasonic irrigation (group II), and MDA with K-file (group III) were performed and the teeth were again placed in CBCT scanner and results analyzed using the chi-square test.
The apical vapor lock was formed in all the samples. Out of the 20 teeth in each group, the apical vapor lock was eliminated in 18 samples of EndoActivator group (90%), 16 samples of ultrasonic group (80%), while it was eliminated in 10 samples by MDA (50%).
It is concluded that (1) apical vapor lock is consistently formed during endodontic irrigation in closed canal systems and (2) sonic activation performs better than the ultrasonics and MDA in eliminating the apical vapor lock, with statistically significant difference between all the three groups (p < 0.05).
The results suggest that the apical vapor lock (dead water zone) is consistently formed during routine endodontic irrigation which impedes irrigant penetration till the working length, thereby leading to inefficient debridement. Hence, to eliminate this vapor lock, techniques, such as sonics or ultrasonics should be used along with the irrigant after shaping and cleaning of the root canal.
本研究的目的是（i）使用锥形束计算机断层扫描（CBCT）评估在注射器冲洗过程中根管根尖区域气泡的形成（根尖气锁），以及（ii）使用CBCT对EndoActivator、超声和手动动态搅拌（MDA）消除已形成的气锁进行比较评估。
总共60颗拔除的人单根牙平均分为三组，每组20颗牙。将样本从根尖处截冠17毫米，清洁后使用3%次氯酸钠预备至F4 Protaper锉的尺寸。样本用3%次氯酸钠+氯化铯显影剂进行冲洗，并获取术前CBCT图像。在扫描的牙齿中形成根尖气锁后，进行EndoActivator冲洗（第一组）、被动超声冲洗（第二组）和使用K锉进行MDA冲洗（第三组），然后将牙齿再次放入CBCT扫描仪中，并使用卡方检验分析结果。
所有样本均形成了根尖气锁。每组20颗牙中，EndoActivator组有18个样本（90%）的根尖气锁被消除，超声组有16个样本（80%）的根尖气锁被消除，而MDA组有10个样本（50%）的根尖气锁被消除。
得出以下结论：（1）在封闭根管系统的根管冲洗过程中持续形成根尖气锁；（2）在消除根尖气锁方面，声波激活比超声和MDA效果更好，三组之间存在统计学显著差异（p<0.05）。
结果表明，在常规根管冲洗过程中持续形成根尖气锁（死水区域），这会阻碍冲洗液渗透到工作长度，从而导致清创效率低下。因此，为了消除这种气锁，在根管预备和清洁后，应在冲洗液中使用声波或超声等技术。
