Alveolar Bone and Microvascular Changes after Synthetic Bone Regeneration Therapy Using Platelet-Rich Plasma (PRP)

Abstract

In this study, bio-resorbable synthetic bone graft material and platelet-rich plasma (PRP) was applied to extraction sockets in dogs. To examine the relationship between the bone formation and vascular changes, a micro-vascular resin cast model was examined under a scanning electron microscope (SEM). The mandibular premolars of beagle dogs on both sides were extracted and eight sockets were created on mandibular bones. Platelet-rich plasma was made for experimental animals. Synthetic bone (TCP, Japan Medical Material) was grafted on one side for the experimental group and on the other side the synthetic bone was only grafted on the tooth sockets for the control group. Vascular resin injection was performed 14, 30 and 90 days after surgery.
The microvascular resin cast is a method for observing the vasculature and clear, three-dimensional images can be observed through complete infusion of an injected synthetic resin up to the capillaries. SEM images were captured and loaded onto the image programs (Image J, NIH). The bone formation ratio and vascular regeneration ratio was measured.
In the control group at 14 days after operation, newly formed blood vessels were found in the sockets. The blood vessels extended from the bone marrow space vessels were regenerated in the socket. In the experimental group, the socket was filled with the newly formed bone. The regenerated blood vessels were surrounded by new bone. The inside of the socket at 30 days after operation was filled with newly formed bone in both groups. In the control group, thin new bone formation was seen along the blood vessels. In the experimental group, bone trabecula and blood vessels were arranged in the bone marrow space. At 90 days after surgery, in the control group, new bone had filled the inside of sockets. However, we could not definitely identify any new trabeculae. In the experimental group at 90 days after surgery, the resemblance of the pattern of the trabeculae and its vascular network to bone marrow space had become even stronger.
These results suggest that PRP promotes the regeneration of the blood vessels and bone.