The Use of Platelet-rich Fibrin in the Management of Soft Tissue Healing and Pain in Post-extraction Sockets: a Randomized Clinical Trial

Production of PRF membranes A venipuncture was performed, prior of performing any treatment (median basilica vein, median cubital vein, median cephalic vein). Blood was drawn into four sterile, red cover tubes (IntraSpin™, Biohorizons®, Birmingham, Alabama, USA) 10-mL tubes without anticoagulant. The tubes were immediately centrifuged at 2700 rpm for 12 min (~708g) using a vertical/ fixed angle centrifuge (IntraSpin™, Biohorizons®, Birmingham, Alabama, USA). The g-force values were referenced at the bottom of the centrifugation tubes (RCF-max). After centrifugation, each L-PRF clot was removed from the tube and separated from the red element phase at the base with pliers. Four L-PRF clots were squeezed between a sterile metal plate and a metal box to obtain L-PRF membranes, similar in size and thickness.

Surgical procedures and initial clinical measurements The participants underwent periapical radiography or computed tomography (when necessary) and clinical examination to assess the absolute need for dental extraction. The participants underwent initial periodontal treatment, including supra and subgingival scaling, plaque control, and were given oral hygiene instructions.

Before tooth extraction, participants from both groups underwent local anaesthesia with mepivacaine 2% (Mepiadre, Nova DFL, Rio de Janeiro, Brazil). All teeth were extracted using a minimally traumatic procedure. No vertical releasing incisions were performed. To avoid root and bony fractures, the molar teeth were sectioned using a multilaminated drill (Zecrya, Microdont, São Paulo, Brazil). Luxation of the teeth was performed using a periotome followed by removal using forceps. After exodontia, a rigorous inspection and curettage of the socket was performed, followed by irrigation with sterile saline solution (Linhamax, Eurofarma, Rio de Janeiro, Brazil).

The sockets of the test group were filled with two PRF membranes followed by cross suture (Mononylon Ethilon, Johnson & Johnson, NJ, USA) to stabilize the membranes (Figure 1A), while the sockets of the control group received no type of biomaterial (i.e., left to spontaneous healing).

Postoperative control It was prescribed Ibuprofen (400 mg, Advil, Pfizer, São Paulo, Brazil) every 6 h was also prescribed in case of pain. Mouthwash with chlorhexidine gluconate 0.12% (Periogard, Colgate, São Paulo, Brazil) was also prescribed twice per day for 2 weeks. Sutures were removed after 10 days.