Nonsurgical Endodontic Retreatment of a Large Cyst‐Like Periapical Lesion With Buccal and Palatal Cortical Plate Perforations and Maxillary Sinus Involvement: A 2‐Year <scp>CBCT</scp> Follow‐Up Case Report

Abstract

Large cyst-like periapical radiolucencies with cortical perforations are traditionally managed surgically. However, nonsurgical retreatment may be effective when adequate disinfection and seal are achieved. This case report describes the management of a large maxillary periapical lesion involving five endodontically treated teeth (from 21 to 25), associated with buccal and palatal cortical perforations and maxillary sinus involvement. Nonsurgical retreatment using enhanced disinfection and obturation with a hydraulic calcium-silicate sealer was performed. Successfully establishing patency was reflected in the creation of evident sealer puffs. Radiographic follow-up at 8 months and 2 years using Cone-Beam Computed Tomography (CBCT) demonstrated substantial bone fill and near-complete re-establishment of both cortical plates. The patient remained asymptomatic throughout the follow-up period. This case illustrates that, when meticulously executed and supported by modern bioactive materials, nonsurgical retreatment can promote significant healing even in extensive lesions, although surgical intervention remains the recommended secondary option when indicated.