Clinicopathological study of periapical scars

Background/purpose: Periapical scar (PS) is an alternative healing process with the formation of scar tissue after appropriate endodontic treat ments/retreatments with or without periapical surgeries. This retrospective study evaluated the clinical, radiographic, and histopathological features of 7 PSs. Materials and methods: The clinical, radiographic, and histopathological data of 7 PSs were collected and analyzed. Results: The 7 PSs were taken from the maxilla (3 cases) and mandible (4 cases) of 3 men and 4 women. The most frequently involved teeth were maxillary or mandibular incisors (4 cases) and first or second molars (3 cases). Of 7 PS patients, 6 had none of symptoms, 5 had previous nonsurgical endodontic treatments/retreatments, and 2 had previous endodontic treatments/ retreatments plus periapical surgery. Radiographically, all 7 PS cases presented as a persistent and well-defined periapical radiolucent lesion for a long period of time. Microscopically, all 7 surgical specimens of PS showed dense fibrous collagenous tissues with one having amalgam particles in the scar tissue. Conclusion: PSs do have their common clinical and radiographic features. When the periapical radiolucent lesion is well-defined, persistent without a significant change of its size, and free from symptoms and signs after a long-term follow-up; the involved tooth has no evidence of root fracture and healthy periodontium except the periapical radiolucency; and the previous endodontic treatment/retreatment or periapical surgery is well performed with an adequate root canal or retrograde filling, then the PS may be a possible diagnosis and a close follow-up may be a more conservative treatment strategy for this condition. (c) 2021 Association for Dental Sciences of the Republic of China. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons. org/licenses/by-nc-nd/4.0/).