Platelet-rich plasma activity on maxillary sinus floor augmentation by autologous bone

Objectives: This work aims to evaluate the regenerative potential of platelet-rich plasma (PRP) on an implant site of peculiar clinical impact, such as sinus augmentation. Material and methods: Sixteen consenting patients (11 females and five males), with symmetrical maxillary sinus atrophy, underwent bilateral sinus floor augmentation, using autologous (iliac crest) bone on one side and PRP plus autologous bone contralaterally. Implants were inserted 4, 5, 6 and 7 months after surgery in the patients randomly split into four groups. Orthopantomographies, computed tomography with transverse image digital reconstructions and densitometries were used to monitor the treatment progress. A core biopsy was performed at the site of implant. Results: Clinical performance across both sites showed no statistical significance (P=0.414). Densitometric values were higher at PRP sites (mean Hounsfield units similar to+57%), even if densitometry converged in the two sites 8 months after surgery. Histology documents enhanced bone activities in sites treated with PRP, 4 months after surgery. Reduced bone activity was observed in both sites 5, 6 and 7 months after surgery. Bone amount, higher in sites treated with PRP (mean trabecular bone volume similar to +37%), decreased in both sites over time. Conclusions: Our results seem to indicate a certain regenerative potential of PRP when used with autologous bone. The effect of this enhancement of bone regeneration appeared to be restricted to shorter treatment times. A progressive extinguishment of the PRP effect is recorded after an interval longer than 6-7 months.