Authors: Harrison JW, Jurosky KA.
Title: Wound Healing in the Tissues of the Periodontium following Periradicular Surgery. III. The Osseous Excisional Wound.
Journal: J Endod
Date: Feb 1992
Citation: 18(2):76-80
Category: Endodontic Surgery
Evidence-based Ranking: 5
Purpose/Objectives: To describe the osseous response to excisional wounding at post surgical intervals ranging from 1 to 28 days.

Materials & Methods: Rhesus monkeys had 24 total flaps reflected in the anterior and posterior sextants of the maxilla and mandible. An excisional wound was made in interdental bone by penetrating the cortical plate with a #10 round bur in a high-speed, with water coolant, creating a wound similar to that produced during surgery. The flaps were stabilized by interrupted plain gut sutures. Surgery and sacrifices were scheduled to provide post-surgical periods of 1 to 4 days and 14 to 28 days.

Results: At 1 through 3 days after surgery, the wound remained filled with a coagulum of disorganized, interrupted, fibrin stands. Erythrocytes, inflammatory cells and tissue debris were present. Peripheral devitalization of the cancellous bone was present. At day 4, endosteal tissues were proliferating into the coagulum. An increase in cellularity and vascularity is present; inflammatory and reparative cells move into the coagulum. At day 14, endosteal tissue and multiple woven bone trabeculae occupied about 4/5 of the excisional wound. New trabeculae had large lacunae with plump osteocytes and were rounded by an osteoid layer. Osteoblastic activity was evident throughout the site. Woven bone formation was seen on the cortical and trabecular devitalized bone at the wound edges. At day 28, the trabeculae had coalesced and occupy a slightly greater total area of the defect as compared with the endosteal tissue which was predominant at 14 days. The new trabeculae showed a decreased cellular activity, and a layer of cells of the delimiting membrane (cells similar to the periosteum) were actively depositing on the outer surface.

Author’s Conclusion: A new bone matrix formed directly on devitalized bone surfaces, osteoclastic activity was not observed within the excisional wound site, the endosteal tissues play the major role in osseous excisional wound healing, and the periosteum (delimiting membrane) does not function in bone repair until the excisional wound is almost filled with woven bone trabeculae of endosteal tissue origin.