Clinicopathological study of periapical scars

Abstract

Background/purpose: Periapical scar (PS) is an alternative healing process with the formation of scar tissue after appropriate endodontic treatments/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.

Keywords: Clinical feature; Histopathological feature; Periapical scar; Radiographic feature.

Figure 1

Histopathological features of periapical scars (PSs). (A, B and C) Low-, medium-, and high-power microphotographs of a PS showing dense fibrous collagenous tissues with a few spindle-shaped fibroblasts scattered among collagen fibers and no inflammation. (D, E and F) Medium- and high-power microphotographs of a long-duration PS exhibiting dense fibrous collagenous tissues with marked hyalinization and fewer spindle-shaped fibroblasts than those seen in the PS specimen shown in A, B and C. (Hematoxylin and eosin stain; original magnification; A, 4×; B, 10×; C, 40×; D, 10×; E, 20×; F, 40×).

Figure 2

Histopathological features of a periapical scar (PS) with embedded amalgam particles. (A and B) Medium-power microphotographs of a PS exhibiting aggregates of small and large black amalgam particles in the dense fibrous connective tissue. (C) Aggregates of small amalgam particles were surrounded by fibrous connective tissue with a more significantly mild chronic inflammatory cell infiltrate. (D) However, aggregates of large amalgam particles were surrounded by fibrous connective tissue with minimal chronic inflammation. (Hematoxylin and eosin stain; original magnification; A, 10×; B, 20×; C, 40×; D, 40×).