(A,B) Histological images of the evolution of defects in rat calvaria in the experimental periods of 14 and 42 days, respectively. BMG—defects filled with HA/β-TCP covered by a bovine biological membrane; BFMG defects filled with HA/β-TCP and heterologous fibrin biopolymer covered with bovine biological membrane; BFMLG defects filled with HA/β-TCP and heterologous fibrin biopolymer covered with bovine biological membrane and PBMT. Bone border (b), reactive connective tissue (RT), biomaterial particles (B), bovine biological membrane (asterisk), new bone tissue (blue triangle), fibrous connective tissue (fCT), collagen fibers (black arrow), blood vessel cells (red arrow). H.E. Original 10× magnification; bar = 500 µm and inserts, enlarged 40× images; bar = 100 µm).