Revascularization of an excisional wound in gingiva and oral mucosa. A scanning electron microscopic study using corrosion casts in rats.

The purpose of this study was to examine microvascular regeneration associated with gingival wound healing. A full-thickness piece of gingiva and oral mucosa was excised along the palatal aspect of the right maxillary first and second molars in 20 young Wistar rats. The contralateral side served as unoperated control. After 2, 4, 7, 10 or 20 days of healing, microvascular corrosion casts were produced and examined by scanning electron microscopy. At 2 days, vessels surrounding the wound were dilated and impressions representing sites of leukocyte margination were prominent in the walls of venules. Capillary buds were emerging from venules and capillaries. At 4 days, the vessel buds had lengthened and connected in pairs to produce capillary loops. At 7 days, new vessels extended deeply into the wound space, mainly from the medical side, in a palisade-like pattern. At 10 days, the denuded bone surface was still not completely revascularized and Volkman's canals opening to the wound area were empty. At 20 days, the bone surface was covered by large, irregular vessels which originated mainly from the palatal mucosa. The periodontal ligament was less important in the tissue repair process, while the bony vasculature contributed little or not at all to revascularization of the healing gingiva and palatal mucosa.