WOUND-HEALING AND REVASCULARIZATION - A HISTOLOGIC OBSERVATION OF EXPERIMENTAL TOOTH ROOT FRACTURE

We used dogs as an animal model to generate tooth root fracture and to observe the wound-healing process of the fracture. Histologic examina tion of the specimens revealed that the early reaction of the wound he aling was infiltration of inflammatory cells particularly at the coron al part of the fracture, whereas less inflammation but more abundant c ollagen fibers were seen at the apical part of the fracture (15 and 30 days). inflammation lasted for more than 90 days and then subsided. A t bay 180, bone tissue healing was observed. Revascularization of the pulp tissues reached a high level at the same stage that bone healing took place. Our data suggest that in tooth root fracture, the regenera tion of blood vessels is important in the wound-healing process and th e revascularization is synchronized with the fracture wound healing. I n this animal model the complete hard tissue healing could rake as lon g as 6 months.