Tensile Strength Essay Comparing Three Different Platelet-Rich Fibrin Membranes (L-PRF, A-PRF, and A-PRF+): A Mechanical and Structural In Vitro Evaluation oleh Mara Simões-Pedro, Pedro Maria B. P. S. Tróia, Nuno Bernardo Malta dos Santos, António M. G. Completo, Rogerio Moraes Castilho, Gustavo Vicentis de Oliveira Fernandes