My patient needed the extraction of two adjacent teeth in the maxillary arch. He needs Guided Bone Regeneration for site development to place implants. The vestibule is very, very shallow and prevents primary closure by releasing the flap. My experience with PTFE and college membranes, when exposed, tells me not to rely on membranes as a solution, for this case. I am considering using PRF as a membrane, but I have no experience in trying it under the above described circumstances. What do you recommend in this case?