LAUSR

OBJECTIVE To evaluate the effect of resting and compression time after centrifugation on the physical properties of platelet rich fibrin (PRF) membranes, and to provide optimal guidance regarding the clinical preparation of PRF. MATERIALS AND METHODS A total of 12 volunteers enrolled in this study divided into 2 groups equally. For each volunteer, 6 tubes of 10 mL venous whole blood was drawn. To evaluate the influence of resting time after centrifugation, PRF clots were taken out 0, 1, 3, 5, 7, and 10 min from tubes following centrifugation, and then the weight, size, maximum stress, and maximum strain of each group were measured. To evaluate the influence of compression time on the preparation of PRF membranes, the weight ratio of PRF membranes to PRF clots was calculated by compression for 10 s, 30 s, 60 s, 90 s, 120 s, and 180 s, respectively. Scanning electron microscopy was performed to observe the cross-linking of the fibers within membranes, and the maximum stress and strain of PRF membranes were tested followed by stress-strain curve analysis. RESULTS The weight and volume of PRF clots and PRF membranes increased in size and weight reached the top at 3 min, followed by a decrease after 7-min resting. The maximum strain of the PRF membranes after 10 min decreased significantly compared to the 3-min and 5-min groups. The maximum stress was found at 3 min followed by a statistical decrease when resting time went on. Scanning electron microscopy demonstrated that the internal fibrous structure of the PRF membranes was looser when the compression time was less than 60 s when comparing the 90-s group. The maximum stress of PRF membranes was shown using a wait period of 3 min post-centrifugation followed by compression for 120 s. CONCLUSION The findings from the present study demonstrate that the time post-centrifugation of PRF membranes showed a maximum weight, volume, and mechanical properties after resting for 3-5 min in the tube post-centrifugation followed by a compression time of 120 s. CLINICAL RELEVANCE Although research to date has focused primarily on centrifugation protocols, this study revealed for the first time that the resting time post-centrifugation greatly affected the mechanical properties of PRF. This study demonstrated that the resting and compression time after centrifugation influences the mechanical strength of PRF membranes, which might explain differences in PRF characteristics prepared by different clinicians that may provide a standard guide for preparation of PRF membranes.