Maresin 1 Promotes Wound Healing and Socket Bone Regeneration for Alveolar Ridge Preservation.

Tooth extraction results in alveolar bone resorption and is accompanied by postoperative swelling and pain. Maresin 1 (MaR1) is a proresolving lipid mediator produced by macrophages during the resolution phase of inflammation, bridging healing and tissue regeneration. The aim of this study was to examine the effects of MaR1 on tooth extraction socket wound healing in a preclinical rat model. The maxillary right first molars of Sprague-Dawley rats were extracted, and gelatin scaffolds were placed into the sockets with or without MaR1. Topical application was also given twice a week until complete socket wound closure up to 14 d. Immediate postoperative pain was assessed by 3 scores. Histology and microcomputed tomography were used to assess socket bone fill and alveolar ridge dimensional changes at selected dates. The assessments of coded specimens were performed by masked, calibrated examiners. Local application of MaR1 potently accelerated extraction socket healing. Macroscopic and histologic analysis revealed a reduced soft tissue wound opening and more rapid re-epithelialization with MaR1 delivery versus vehicle on socket healing. Under micro-computed tomography analysis, MaR1 (especially at 0.05 mu g/mu L) stimulated greater socket bone fill at day 10 as compared with the vehicle-treated animals, resulting in less buccal plate resorption and a wider alveolar ridge by day 21. Interestingly, an increased ratio of CD206(+):CD68(+) macrophages was identified in the sockets with MaR1 application under immunohistochemistry and immunofluorescence analysis. As compared with the vehicle therapy, local delivery of MaR1 reduced immediate postoperative surrogate pain score panels. In summary, MaR1 accelerated extraction wound healing, promoted socket bone fill, preserved alveolar ridge bone, and reduced postoperative pain in vivo with a rodent preclinical model. Local administration of MaR1 offers clinical potential to accelerate extraction socket wound healing for more predictable dental implant reconstruction.