Effects of injectable platelet rich fibrin on bone remodeling in combination with DBBM in maxillary sinus elevation: a randomized preclinical study.

OBJECTIVES This study aims to assess the angiogenic and osteogenic capacity in rabbit sinus model grafted with Deproteinized bovine bone mineral (DBBM) particles soaked in injectable Platelet rich fibrin (iPRF), both of which interacted to form an integrated block. MATERIALS AND METHODS Among sixteen rabbits, bilateral maxillary sinuses were randomly grafted with either DBBM containing iPRF (iPRF+DBBM group), or DBBM alone (DBBM group). After a 4 and 8-week healing period, animals were sacrificed for micro-CT, histological and immunofluorescence analyses, respectively. RESULTS New bone formation in the iPRF+DBBM group was largely observed around the basal bone wall and Schneiderian membrane (SM), which further substitute the bone grafting material in a bidirectional remodeling pattern. Although the ultimate amount of bone volume was of no significant difference between two groups in radiographical image, the expression of ALP and TRAP staining were significantly higher in the experimental group with numerous vascular formations at 4th week. Moreover, the substitution rate of DBBM by new bone formation after 8 weeks was significantly higher in the experimental group. As a result, mature collagen fibers were detected in the larger amount of area in iPRF+DBBM group even at an early stage. CONCLUSION iPRF+DBBM accelerated vascular formation, bone remodeling and substitution of bone graft materials at the early healing period, even though it failed to increase the bone volume in a long-term period. This integrated grafting biomaterial will have great potential in the application of sinus augmentation, which provides a favorable environment for early implant placement.