Evaluation of the Possible Synergic Regenerative Effects of Platelet-Rich Plasma and Hydroxyapatite/Zirconia in the Rabbit Mandible Defect Model

Background: platelet-rich plasma (prp) and bioceramics such as hydroxyapatite (ha) and zirconium oxide (zro_2) are used to reconstruct mandibular defects. we sought to determine the synergistic effects of ha/zro_2 and prp and compare their osteogenic activity. methods: zro_2 scaffolds were constructed by the slurry method and were then coated with ha and impregnated by prp/ heparan sulfate (hs). bilateral mandibular defects were created in 26 male rabbits. in 20 rabbits, the left defects were treated with ha/zro_2/prp (group 1) and the corresponding right defects were filled with ha/zro_2 (group 2). the 6 remaining models were treated with prp gels at both sides (group 3). the osteo conductivity of ha/zro_2/prp was compared with that of ha/zro_2 or prp by radiological and histological methods after the follow-up period, at weeks 2, 6 and 8. the statistical analyses were performed by anova and lsd using spss, version 16.0, for windows (p<0.05). results: after 2 weeks, the percentage of the surface occupied by bone was significantly higher in the ha/zro_2/prp-treated defects than in the prp-treated defects (p=0.007). osteoblast and osteocyte counts were higher significantly in the prp- treated group (p=0.032); however, the cells had not started matrix formation on a large scale and just small islands of osteoid with trapped osteocytes were observed. in the long term, the regenerative potential of all the scaffolds was the same. conclusion: ha/zro_2 showed a superior osteoconductive capacity over prp in the short term; however, they showed norm synergic effects.