Histologic and histomorphometric assessment of sinus-floor augmentation with beta-tricalcium phosphate alone or in combination with pure-platelet-rich plasma or platelet-rich fibrin: A randomized clinical trial.

BACKGROUND: The potential effects of adding pure platelet-rich plasma (P-PRP) or platelet-rich fibrin (PRF) to beta-tricalcium phosphate (beta-TCP) graft substitute on bone formation and regeneration after maxillary sinus-floor elevation remains unclear. PURPOSE: To compare the histologic and histomorphometric outcomes of maxillary sinus-floor augmentation among beta-TCP alone, P-PRP-mixed beta-TCP, and PRF-mixed beta-TCP. MATERIAL AND METHODS: In this randomized clinical trial, elevated sinus cavities were grafted with beta-TCP (the control group), P-PRP-mixed beta-TCP (the P-PRP group), and PRF-mixed beta-TCP (PRF group). The sample was composed of 26 patients: 9 subjects in control and P-PRP groups, and 8 subjects in PRF group. After a 6-month, healing period, bone graft biopsies were harvested prior to implant placement, and the specimens were analyzed. The main outcome variables included findings of histologic and histomorphometric analyses of the bone graft biopsies. The data were analyzed by ANOVA and Tukey HSD tests. RESULTS: The mean percentages of new bone formations were 33.40 +/- 10.43%, 34.83 +/- 10.12%, and 32.03 +/- 6.34% in control, P-PRP, and PRF groups, respectively, with no significant differences (P > .05). Mean percentages of residual graft particle area were 30.39 +/- 10.29%, 28.98 +/- 7.94%, and 32.66 +/- 7.46% in control, P-PRP, and PRF groups, respectively, with no significant differences (P > .05). The mean percentages of soft-tissue area were 36.21 +/- 10.59%, 36.19 +/- 13.94%, and 35.31 +/- 10.81% in control, P-PRP, and PRF groups, respectively, with no significant differences (P > .05). Mean densities of osteoblasts, osteoclasts, osteocytes, and capillary vessels showed insignificant difference between groups (P > .05), but osteoprogenitor cells were lower and inflammatory cells were higher in the PRF group than those in other groups (P < .01). Biopsies of P-PRP, PRF, and control groups showed similar composition and distribution of histologic structures. CONCLUSION: These findings suggested that adding P-PRP or PRF to beta-TCP graft substitute was not beneficial on new bone formation and regeneration, and P-PRP plus beta-TCP or PRF plus beta-TCP is not superior to beta-TCP alone.