Histologic and radiological observations of a human immature premolar with pulp necrosis treated with regenerative endodontic procedure - A case report of a four-year follow-up

Background: Reports are found on long-term radiographic follow-up of teeth treated with regenerative endodontic techniques, but scarce literature is observed regarding the tissue formed in the root canal. A four-year radiographic follow-up with histologic findings in an immature mandibular premolar with dens evaginatus that underwent a regenerative endodontic procedure (REP) is presented here. After four years following REP, the tooth was extracted for orthodontic purposes thereby presenting an opportunity to report the histologic findings.Summary: The radiographic changes included a slight root lengthening and thickening and apex closure. Histologic evaluation revealed a fibrous connective tissue with an inflammatory infiltrate in the canal space. In the apical region, cementum-like irregular mineralization developed toward the center, giving the appearance of a closed apex. Root thickening, increase in length, and radio-graphic closure of the apex occurred due to cemental hyperplasia.Conclusion: After 4 years following REP in an immature mandibular premolar with apical periodontitis, granulation tissue had formed in the root canal, indicating repair and not regeneration.(c) 2023 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).