Objectives: 1) to compare mandibular bone regeneration by applying autologous bone, platelet-rich plasma and two biomaterials (synthetic calcium hydroxyapatite, and demineralized bone matrix), and thus establish the potential benefits of these biomaterials in the regeneration of postextraction alveolar bone, 2) to identify wich of them accelerates more bone regeneration and 3) to determine whether there are differences in the postoperative period (pain, swelling, trismus, infection) depending on the material used. Study Design: It consists in a prospective, controlled (with a split- mouth design) and double blinded study. We use as a model an easily reproducible non-critical bone defect: the defect that remains after extraction of mandibular impacted third molar. The study design is based on the extraction of two mandibular impacted third molars in a patient during the same surgical procedure by the same surgeon. We assessed postoperative clinical data, and short, medium and long term neoformation of alveolar bone after extraction. We compared the two sockets (right and left), which had been grafted in a different way with the various elements mentioned above. In addition, we compared the postoperative inflammatory symptoms between groups. Results: The highest acceleration in bone formation was observed in groups in which we used autologous bone and demineralized bone matrix. There were no statistically significant differences between groups regarding pain, swelling, trismus and infection throughout the postoperative period. Conclusions: According to the results of our study, autologous bone persists as the gold standard material for bone regeneration. Among the assessed biomaterials, demineralized bone matrix has yielded the best results obtained. No significant differences in the postoperative (pain, swelling, trismus and infectious events) were observed, depending on the type of material used as a graft.