Abstract
The process of wound healing after a flap operation, regeneration of the gingival epithelium and gingival connective tissues, was investigated.
Seventy male Wistar rats weighing approximately 90g were used The full thickness of the palatal gingiva was elevated by the operation from M1 to M3 in the left maxilla, the right side was the control.
The intervals of observation after the operation were 2, 4, 16, 32, 64 and 128 hrs.
The methods of observation were as follows:
1. The healing process was observed by histopathological examination (H-E staining).
2. Labeled silver grains present in basal cells the gingival epithelium were detected by DNA activity measured by 3H-thymidine autoradiography.
3. The density of silver grains during collagen metabolism was determined by 3H-proline autoradiography.
4. The labeling index of epithelial basal cells was calculated for labeled cells from the elevated flap margin.
The following results were obtained:
1. Judging from histopathological findings, regeneration of the gingival epithelium occurred from 64 to 128 hr after the flap operation.
2. 3H-thymidine autoradiography revealed that in early regeneration of the gingival epithelium, the activity of epithelial basal cells increased in the portions distant from the flap margin and gradually proceeded to the healing wound, whereas the activity of fibroblasts was increased on the root surface in the epithelium after 64 hr.
3. 3H-proline autoradiography revealed that after the wound edges in the gingival epithelium, recovered, activity of fibroblasts increased during the collagen metabolism, continuing throughout the 128 hr.
4. Laveling indicies showed a tendency to be higher from to 128 hr, with a peak at 14 hr.
