Investigation of the effectiveness of platelet rich fibrin on new bone formation in rabbit calvarial bone defects

The present study aimed to investigate the effectiveness of platelet-rich fibrin (PRF) on bone regeneration when used alone or in combination with hydroxyapatite (HA)/beta-tricalcium phosphate (βTCP). 20 New Zeland rabbits were used in the study. On the calvarium of each rabbit, 4 standarized defects, 6-mm in diameter, were created. One of the defects was used as control and the other three were used as experimental groups. Experimental defects were filled with PRF, HA/βTCP and PRF mixed with HA/βTCP. Half of the rabbits were sacrificed at 4th week and other half sacrificed at 8th week. After micro-computed tomography (micro-CT) scanning, the samples were sent for histological and histomorphometric analysis. Histomorphometric analysis showed that increase in new bone formation at 8th week was statistically significant in all groups except control group in comparison to the new bone formation at 4th week. Micro-CT analysis showed that increase in new bone formation at 8th week was statistically significant in all groups in comparison to the new bone formation at 4th week. Histomorphometric and micro-CT analysis showed that both PRF and HA/βTCP significantly increased new bone formation in comparison to the control group at 4th week and 8th week. When PRF was used in combination with HA/βTCP, a further significant increase in new bone formation was observed at 4th week and 8th week compared with that when PRF or HA/βTCP was used alone.To conclude, PRF increases new bone formation either alone or in combination with HA/βTCP. Key Words: Platelet rich fibrin, hydroxyapatite/ beta-tricalcium phosphate, calvarial defect, micro computed tomography, rabbit