Healing following simulated fiber retention procedures in rats.

Healing responses of a simulated fiber retention procedure in rats has been presented. In the area of attached, but severed supracrestal fibers, a loss of cells was observed in the initial stages of repair. Subsequently, connective tissue cells migrated into this area as did blood vessels. A very distinct interface was seen at about 1 week after surgery between the advancing soft tissues from the flap wound surface and the attached, but severed supracrestal fibers. By 4 weeks after surgery, such distinction was absent and supragingival fiber bundles appeared continuous from their cemental attachment over to the adjacent alveolar crest. However, no evidence of cementogenesis was seen at this site which suggests that these attached fibers were attached prior to surgery. The position of the new junctional epithelium appeared to be limited to the level of the retained supracrestal fiber fragments. However, in areas where cementum, and thereby attached fibers, had been removed during surgery, an altered epithelial adherence was usually seen. This altered adherence was in the form of a long junctional epithelium or a short junctional epithelium on top of parallel oriented collagen fibers. The latter also appeared to adhere to the tooth surfaces.