Citation: Anindita Talukdar et al (2021). Working Length Determination Using Apex Locator and Cone Beam Computed Tomography in Presence of Three Irrigating Solutions in Primary Teeth: An In Vitro Comparative Study. Saudi J Oral Dent Res, 6(2): 92-96. 92 Saudi Journal of Oral and Dental Research Abbreviated Key Title: Saudi J Oral Dent Res ISSN 2518-1300 (Print) |ISSN 2518-1297 (Online) Scholars Middle East Publishers, Dubai, United Arab Emirates Journal homepage: https://saudijournals.com Original Research Article Working Length Determination Using Apex Locator and Cone Beam Computed Tomography in Presence of Three Irrigating Solutions in Primary Teeth: An in Vitro Comparative Study Anindita Talukdar 1* , Prakash Chandra 2 , Latha Anandakrishna 3 1 Private consultant, Pedodontist Guwahati, India 2,3 Professor, Department of Paediatric Dentistry, Faculty of Dental Sciences, M S Ramaiah University of Applied Sciences, Bengaluru, India DOI: 10.36348/sjodr.2021.v06i02.002 | Received: 02.02.2021 | Accepted: 12.02.2021 | Published: 16.02.2021 *Corresponding author: Dr. Anindita Talukdar Abstract The purpose of the present study was to determine the working length using electronic apex locator in various intracanal mediums and cone beam computed tomography scan and to compare the lengths with the actual length of the tooth. Methods: In an in vitro setting, a total of 45 primary molar roots were decoronated till the cemento enamel junction for standardization, working length was measured with the Apex DSP (Septodont, France) at the ‘apex’ in presence of three different irrigating solutions namely 0.9 % saline, 0.2 % chlorhexidine and 2.5 % sodium hypochlorite. The radiological working length was then calculated with cone beam computed tomography scans. The collected data was analyzed using descriptive statistics. Independent‘t’ test was done to compar e the working length between the groups. Results: Findings showed there was significant difference in working length determination using apex locator in presence of saline and chlorhexidine when compared to sodium hypochlorite. Also working length determination with cone beam computed tomography compared to actual length did not show any significant difference. Conclusion: Apex DSP can be considered to be accurate across a variety of irrigants commonly used in the pediatric endodontic practice. A CBCT scan can be used as a diagnostic tool for pulpal treatment when treating multiple carious lesions. Keywords: Working length, apex locator, chlorhexidine, sodium hypochlorite, Cone beam computed tomography. Copyright © 2021 The Author(s): This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC BY-NC 4.0) which permits unrestricted use, distribution, and reproduction in any medium for non-commercial use provided the original author and source are credited. INTRODUCTION Endodontic treatment in pedodontics requires treatment of pulpally involved primary and young permanent teeth in children to maintain the integrity and health of the oral tissues and also it is desirable to maintain pulp vitality wherever possible[1]. In permanent teeth, definitive rules for successful endodontic therapy have been established such as dense obturation and apical/coronal seal. In contrast, in pediatric endodontics, because of open apices, there are technical hitches in estimating the exact root canal length [2]. Working length determination is an important step in successful root canal therapy [3]. The accurate determination of working length has a major impact on the outcome of successful endodontic treatment in primary dentition. Frequently used method for determining working length are periapical radiographs. However there are various shortcomings in using conventional radiographs which includes the sensitivity of the technique, subjectivity and errors due to image magnification, distortions or the superimposition of anatomical structures [4]. Moreover, while performing endodontic procedure in children various factors should be taken into consideration like the time taken for the procedure, feasibility of taking multiple radiographs for working length determination. In such cases apex locator might be of importance as this device can be used with ease and also reduces the number of radiographs. Again with the advent of newer technologies like Cone-beam computed tomography (CBCT) which is a contemporary radiological imaging system, undistorted images can be obtained with a significantly lower- effective radiation dose than conventional computed tomography[5]. Hence the null hypothesis is that there is no significant difference in the diagnostic ability of CBCT scan and apex locator in different solutions when