Histological Evaluation of Gingival and Intrabony Periodontal Defects Treated with Platelet-rich Fibrin Using Different Protocols: A Canine Study.

PURPOSE To histologically compare the effects of platelet-rich fibrin (PRF) produced using different protocols on periodontal wound healing/regeneration in periodontal defects in dogs. MATERIALS AND METHODS Dehiscence-type gingival recession and two-wall intrabony defects were created bilaterally in the maxillary canines and mandibular premolars, respectively, in four beagle dogs. The recession defects were randomly treated with coronally advanced flap (CAF) alone, CAF and PRF produced via fixed-angle centrifugation (F-PRF; Leukocyte and PRF (L-PRF) protocol) or CAF and PRF produced via horizontal centrifugation (H-PRF). After 2 weeks, the two-wall intrabony defects were randomly treated as follows: open flap debridement (OFD), OFD + F-PRF, OFD + H-PRF and OFD + heated albumin with PRF using bio-heat technologies (Alb-PRF). Eight weeks after the 2nd reconstructive surgery, the animals were euthanised for histological evaluation. RESULTS In the PRF-applied defects, new bone and new cementum formation occurred to varying degrees regardless of the protocols used to produce PRF. Particularly in the two-wall intrabony defects, new bone formation extended from the host bone toward the coronal region of the defects in the H-PRF applied sites compared with those in the OFD, F-PRF and Alb-PRF groups, and the H-PRF group showed the greatest amount of newly formed cementum. CONCLUSION PRF induced periodontal regeneration in gingival recession and two-wall intrabony defects in dogs. Further studies are needed to determine the optimal protocol for obtaining predictable periodontal regeneration in periodontal defects in humans.