Pulpal blood flow in immature permanent dog teeth after replantation.

Pulpal blood flow (PBF) was measuring by H2-gas clearance in 35 replanted (incisors and premolars) and 22 contralateral control dog teeth. The PBF measurements were taken 6, 10, 16, 21 and 28 days after replantation. At 6, 10 and 16 days after replantation there was no measurable blood flow in the coronal pulp of either replanted incisors or premolars. 21 days after replantation a considerable reduction in PBF was measured in all replanted teeth. On average, PBF was reduced to about one fifth of PBF in the simultaneously measured contralateral controls. Four weeks after replantation, a more than threefold increase in PBF was measured in premolars with two roots, while PBF in premolars with one root and incisors was consistently reduced to an average of 40% of the controls. The vascular pattern of the teeth 4 wk after replantation was identified with perfusion of silicon rubber. The measurements suggest that replanted multirooted teeth revascularize more easily than single-rooted teeth, and that pulpal repair is restored by a gradual replacement and proliferation of new tissue.