Kaushal Ravneet, Bansal Ramta, Malhan Sunil
Department of Conservative Dentistry and Endodontics, Desh Bhagat Dental College and Hospital, Mandi Gobindgarh, Punjab, India.
Department of Conservative Dentistry and Endodontics, Luxmi Bai Institute of Dental Sciences and Hospital, Patiala, Punjab, India.
J Conserv Dent. 2020 Jan-Feb;23(1):71-78. doi: 10.4103/JCD.JCD_43_20. Epub 2020 Oct 10.
Irrigants remove or dissolve smear layer formed during instrumentation. Thus it is important to study the effect of different irrigant solutions on smear layer removal.
The aim of this study is to determine which irrigant effectively removes the smear layer from the coronal, middle, and apical third of the root canal.
One hundred and twenty single-rooted mandibular premolars were decoronated and biomechanical preparation was done through hand instrumentation up to size 40 k file with 2.5% NaOCl irrigation between each successive filing, followed by irrigation with 5 ml of saline. The teeth were divided into Groups I, II, III, and IV containing 30 samples each and irrigated with 5 ml of 17% ethylenediamine tetraacetic acid (EDTA), 10% Citric acid, 7% Maleic acid and normal saline respectively for 1 min and final irrigation was done with 5 ml of distilled water of each sample. The canals were dried with 2% absorbent paper points. The roots were then split with a chisel and mallet. One-half of each tooth was selected and then was analyzed using a scanning electron microscope. The dentinal surfaces were observed at the cervical, middle, and apical third with ×2000 for the smear layer. The scores were attributed, according to Torabinejad . rating system.
7% maleic acid and 10% citric acid both are equally effective in smear layer removal from coronal and middle third, but in apical third 7% maleic acid is more effective than 10% citric acid. Between citric acid and EDTA, both are equally effective in smear layer removal from coronal and middle third, but in apical third, 10% citric acid is more efficacious than 17% EDTA.
Within the limitations of the study, it can be concluded that all three tested irrigants removed the smear layer from coronal, middle, and apical third. However, in apical third 7% maleic acid is the most efficacious irrigant in smear layer removal.
冲洗剂可去除或溶解根管预备过程中形成的玷污层。因此，研究不同冲洗剂溶液对玷污层去除的效果很重要。
本研究的目的是确定哪种冲洗剂能有效去除根管冠部、中部和根尖三分之一处的玷污层。
选取120颗单根下颌前磨牙，去除牙冠，通过手动器械进行生物力学预备，直至40号K锉，每次锉削后用2.5%次氯酸钠冲洗，随后用5毫升生理盐水冲洗。将牙齿分为I、II、III和IV组，每组30个样本，分别用5毫升17%乙二胺四乙酸（EDTA）、10%柠檬酸、7%马来酸和生理盐水冲洗1分钟，每个样本最后用5毫升蒸馏水冲洗。用2%吸水纸尖干燥根管。然后用凿子和锤子劈开牙根。选取每颗牙齿的一半，用扫描电子显微镜进行分析。在颈段、中段和根尖三分之一处观察牙本质表面，放大2000倍观察玷污层。根据Torabinejad评分系统进行评分。
7%马来酸和10%柠檬酸在去除冠部和中部三分之一处的玷污层方面同样有效，但在根尖三分之一处，7%马来酸比10%柠檬酸更有效。在柠檬酸和EDTA之间，两者在去除冠部和中部三分之一处的玷污层方面同样有效，但在根尖三分之一处，10%柠檬酸比17% EDTA更有效。
在本研究的局限性内，可以得出结论，所有三种测试冲洗剂都能去除根管冠部、中部和根尖三分之一处的玷污层。然而，在根尖三分之一处，7%马来酸是去除玷污层最有效的冲洗剂。
