“…A previous systematic review (Ahmad & Pani, 2015) was carried out; however, some limitations in this study need to be overcome to increase the certainty of the evidence, as most of the included studies were in vitro investigations. The most reliable evidence is obtained from well-conducted clinical studies and, since 2013 (the search date of the previous systematic review), several clinical studies have been performed to assess the accuracy of different EALs used for working length determination in primary teeth (Abdullah et al, 2016;Alafandy, 2018;Awasthi et al, 2017;Balaji & Pravallika, 2019;Bhat et al, 2017;Caliskan et al, 2021;Dandempally et al, 2013;Davalbhakta et al, 2021;de Alencar et al, 2019;Hafiz, 2018a;Koruyucu et al, 2018;Kumar et al, 2016;Nellamakkada et al, 2020;Nogorani et al, 2014;Oznurhan et al, 2015;Rathore et al, 2020;Sankar & Jeevanandan, 2021;Senthil et al, 2016;Sivadas et al, 2013;Soruri et al, 2013;Wankhade et al, 2013). However, the results of these studies have not been are based on clinical studies with low methodological quality and high heterogeneity, which require careful interpretation for clinical practice.…”