Regeneration of Microcirculation and Alveolar Bone after Application of Platelet-Rich Plasma

Abstract

In order to model the vascularization stage of periodontal recovery, platelet-rich plasma (PRP) was applied to the sockets of the beagle dog's dentition. Microvascular resin injection was performed 14, 30, and 90 days later and examined by light and scanning electron microscopy to investigate the relationship between bone formation and vascular changes. Bone formation ratios were measured from the scanning electron microscopic images. Fourteen days after the operation, newly formed blood vessels filled the untreated sockets, except for the center portion. These blood vessels had regenerated along the pre-existing bone wall of the socket. In the sockets treated with PRP, however, the sockets were filled with newly formed bone, and regenerated blood vessels were surrounded by new bone. Thirty days after the operation, the insides of the sockets were filled with newly formed porous bone in both groups. In untreated sockets, porous new bone formation was observed along the blood vessels, but in sockets treated with PRP, bone trabecula and blood vessels were arranged in the porous bone. Ninety days after the operation, both treated and untreated sockets contained regenerated normal bone tissue, with bone marrow reproduced along the trabeculae and vascular networks observed. However, the bone formation ratios of the PRP-treated sockets were significantly higher than the untreated sockets after 14 and 30 days. At 90 days, nearly identical bone formation was measured in both groups. Taken together, these observations suggest that PRP application to the extraction sockets advanced bone regeneration and promoted regeneration of the blood vessels.