Background: The purpose of this study was to physico/chemically characterize and evaluate the in vitro cytotoxicity/in vivo bone regeneration of two grafting materials in a rat calvaria model. Materials and Methods: Two particulate grafting materials, Hydroxyapatite (HA)/PLGA (poly [L-lactide-co-glycolide]) composite (MA1) and Tricalcium Phosphate (MA2), were characterized by SEM, TEM, XRD (Rie...