[2-P1-P34] 多血小板フィブリン(PRF)適応時における歯肉組織再生過程の解析

Author: 〇劉宇豪¹、東雅啓¹、高橋聡子²、高橋俊介³、松尾雅斗¹
Affiliation: ¹神歯大　院歯　口腔解剖、²神歯大　院歯　口腔生理、³神歯大　院歯　歯科薬理
Abstract:
Purpose: Platelet-Rich Fibrin (PRF) is widely used for wound healing because it contains many growth factors, such as vascular endothelial growth factor (VEGF). It is a safe and beneficial therapeutic agent for bone formation. We have previously reported on microcirculation during alveolar bone regeneration by PRF. In this study, we investigated the effects of PRF on regeneration process in gingival tissue in the early stage after tooth extraction.Material and Method: Under general anesthesia, blood was collected from each beagle dog (female, 12 months old) before tooth extractions to prepare PRF. Four (first-fourth) premolars were extracted bilaterally in the upper and lower jaws. The right extraction socket was filled with PRF and sutured as the experimental group, the opposite side just extracting the tooth and sutured as the control group. All animals were sacrificed by perfusion-fixation at 1, 3, and 7 days after the operation. The upper jaws were prepared to HE stain and immunostained stain (with CD34 and VEGF) for observed with an optical microscope. The lower jaws were prepared for the mandible and observed with a scanning electron microscope (SEM). Blood flow in the gingiva was measured using a laser Doppler blood flow meter before surgery and sampling.Result and Conclusion: In PRF group, a large number of microvessel was observed in the gingival tissue on the first day after surgery. In contrast, the microvessel in the control group was sparse. Blood flow in the gingiva was significantly higher in the PRF group than before surgery. In the vascular resin cast observation by SEM, a large number of new blood vessels were found on the first day of the PRF group, in concordance with the findings in HE staining. In immunohistochemistry, CD34 showed more positive reaction around blood vessels in the PRF group than the control group. In VEGF, a strong positive reaction was observed in the perivascular tissue in the PRF group on the first day after surgery. Our results showed that PRF has promote the angiogenesis in the gingiva by inducing VEGF expression. Thus, PRF is one of the useful materials for soft tissue regeneration.