Vascular response of the periodontal membrane after replantation of teeth.

Thirteen replanted maxillary central incisors were studied by means of histologic and cleared sections to evaluate the pattern of revascularization of the periodontal membrane and the modification of its vasculature due to root resorption, dentoalveolar ankylosis, and periapical processes. Early reparative activity was noted in the apical and cervical parts of the replanted membrane where proliferating vessels were intermingling with reparative cells and interrupted collagenous fibers. These areas of the membrane corresponded with those receiving a better vascular supply after replantation. The middle third of the membrane, however, showed a scarcity or absence of reparative cells as a result of delayed revascularization. Root resorption, dentoalveolar ankylosis, or periapical processes changed both the tissue specificity of the replanted membrane and its pattern of vascular supply. Revascularization of the pulps showed vacuolar degeneration due to lack of nutrition.