International Journal of Advanced Engineering Research and Science (IJAERS) Peer-Reviewed Journal ISSN: 2349-6495(P) | 2456-1908(O) Vol-8, Issue-8; Aug, 2021 Journal Home Page Available: https://ijaers.com/ Article DOI: https://dx.doi.org/10.22161/ijaers.88.56 www.ijaers.com Page | 497 Apical microleakage evaluation of a new proposal for endodontic sealer associated with hydroxyapatite: an ex vivo study Carlos Eduardo Fontana 1* , Beatriz Anjos do Santos 2 , Mariana Xavier Pilla 2 , Letícia Fernandes Sobreira Parreira 3 , Sérgio Luiz Pinheiro 4 1 Pontifical Catholic University of Campinas (PUC-Campinas), Center for Health Sciences, Postgraduate Program in Health Sciences, Campinas, São Paulo, Brazil. 2 Undergraduate Dentistry and Scientific Initiation PUC-Campinas, Center for Health Sciences, Campinas, São Paulo, Brazil. 3 Postgraduate Program in Health Sciences PUC-Campinas, Center for Health Sciences, Campinas, São Paulo, Brazil. 4 Pontifical Catholic University of Campinas (PUC-Campinas), Center for Health Sciences, Postgraduate Program in Health Sciences, Campinas, São Paulo, Brazil. Received: 14 Jul 2021, Received in revised form: 12 Aug 2021, Accepted: 20 Aug 2021, Available online: 31 Aug 2021 ©2021 The Author(s). Published by AI Publication. This is an open access article under the CC BY license (https://creativecommons.org/licenses/by/4.0/). Keywords— Endodontics, Root canal filling, Dye penetration, apical leakage. Abstract— The filling of the root canal system has a fundamental role in endodontic treatment, since it will take the place of the root pulp, thus the material must act by isolating the root canal system, preventing the penetration of microorganisms and their toxic by-products, which can compromise the prognosis of the procedure. The present study was carried out to evaluate the apical microleakage of a hydroxyapatite modified sealer. After removal of crowns and endodontic instrumentation, 40 selected maxillary single root teeth were randomly divided into two experimental groups (n = 15 each) according to the sealer: GENDO – Endomethasone Sealer / GENDOHX - Endomethasone Sealer +5% hydroxyapatite, and two control groups (n = 5 each). The root canals of specimens from the experimental group were filled with the cold lateral condensation technique. To assess apical microleakage, the apical linear dye penetration was measured microscopically from apex to most coronal part and data were statistically analyzed. Descriptive analyses were performed, followed by the Mann- Whitney test. The mean values of leakage observed in the groups were GENDO – 0,95± 1,80 and GENDOHX – 1,01± 1,82. No significant differences were found between experimental groups (p>0,05). Conclusion: The addition of hydroxyapatite to the endomethasone sealer did not interfere with its apical sealing capacity. I. INTRODUCTION For the endodontic treatment to be successful, a sequence of procedures must be performed inside the root canals, starting with the removal of all organic and inorganic content present inside the root canal [1]. Although the chemical-mechanical preparation is a very important step in the endodontic treatment, modeling and decontamination of the canal will be of no use if the sealing promoted at the end by the endodontic filling is faulty [2]. A three-dimensional root canal filling has a fundamental role in endodontic treatment, since it will take