Evaluation of the effect of the cumulative centrifugation force on the characteristics and the tissue regeneration potential of the platelet rich fibrin: a clinical and laboratory study

Background: Although the platelet-rich fibrin (PRF) gained a considerable popularity as a tissue regeneration technique to
reconstruct the surgical defets, the effect of the cumulative centrifugation force (in terms of speed and time) on its regeneration
potential is unclear.
Material and Methods: Ten patients with maxillary surgical defects were randomly and equally divided into two groups where
in the study group, the centrifugation speed and time were 1500 rpm and 18 minutes respectively and in the control group, these
centrifugation parameters were 2700 rpm and 12 minutes on order. For each patient, the surgical defect was packed with the
clots and an extra clot was assigned for histologic, immunohistochemical and histomorphometric examination.
Results: The laboratory results exhibited that the slower but longer duration centrifugation resulted in a looser fibrin clot with
larger interfiber spaces and deeper penetration of neutrophilic granulocytes. In both groups, the other cells (except for platelets
which were distributed through out the clot) were confined to the proximal ⅓ - ¼ of the clot. But that difference failed to impact
the regeneration potential on the clinical level as assessed by bone formation scale and density changes.
Conclusion: Although changing the comulative centrifugation force resulted in deeper penetration of granulocytes, the
regenerative potential did not enhance, perhaps due to the complex nature of the regeneration process where one element alone
cannot alter the regeneration potential.