{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,18]],"date-time":"2026-10-18T09:25:03Z","timestamp":1792315503461,"version":"4.4.0"},"reference-count":70,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2024,5,4]],"date-time":"2024-05-04T00:00:00Z","timestamp":1714780800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JCM"],"abstract":"<jats:p>The gradual formation of hard tissue along the root canal walls is a natural process associated with aging, typically progressing slowly over time. In reaction to tooth wear, operative procedures, vital pulp treatments, or regenerative endodontic procedures, hard tissue may also accumulate within the pulp canal space at a slow rate. In certain cases, such as dental trauma, autotransplantation, or orthodontic treatment, this deposition of hard tissue can accelerate unexpectedly, resulting in rapid narrowing or complete closure of the root canal space. This situation is called calcific metamorphosis (CM), root canal calcification, or pulp canal obliteration (PCO). Performing conventional endodontic therapy on severely calcified canals presents significant challenges and increases the risk of procedural accidents. Calcified canals introduce such complexity that dedicated negotiation concepts and specially designed instruments have been developed to deal with the challenge. This article seeks to review the existing methods for effectively navigating calcified canals and to introduce the buckling resistance activation test (BRAT) technique.<\/jats:p>","DOI":"10.3390\/jcm13092703","type":"journal-article","created":{"date-parts":[[2024,5,6]],"date-time":"2024-05-06T14:26:11Z","timestamp":1715005571000},"page":"2703","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":25,"title":["Negotiation of Calcified Canals"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2844-5338","authenticated-orcid":false,"given":"Antonis","family":"Chaniotis","sequence":"first","affiliation":[{"name":"Private Practice, 17676 Kallithea, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hugo","family":"Sousa Dias","sequence":"additional","affiliation":[{"name":"Private Practice, Dentistry Department, CESPU-IUCS University, 4585-116 Gandra, Portugal"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anastasia","family":"Chanioti","sequence":"additional","affiliation":[{"name":"School of Dentistry, National and Kapodistrian University of Athens (NKUA), 11527 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2024,5,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"223","DOI":"10.3109\/00016358209019816","article-title":"Failures and healing in endodontically treated non-vital anterior teeth with posttraumatically reduced pulpal lumen","volume":"40","author":"Cvek","year":"1982","journal-title":"Acta Odontol. 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