Bone regeneration is often required to provide adequate oral rehabilitation before dental implants. Vertical ridge augmentation is the most challenging of all situations, and often requires the use of autologous bone grafting. However, autologous bone grafting induces morbidity, and the harvestable bone is limited in quantity. Alternatives to autologous bone grafting include bovine-bone-derived biomaterials, which provide good clinical results and synthetic bone substitutes that still fail to provide a reliable clinical outcome. Synthetic biomimetic calcium phosphate (SBCP) biomaterials, consisting of precipitated apatite crystals that resemble in composition and crystallinity to the mineral phase of bone, arise as alternatives to both bovine bone and the current sintered bone substitutes. This study aims to compare the vertical bone regeneration capacity of the SBCP (MimetikOss, Mimetis Biomaterials) with that of a deproteinized bovine bone matrix (DBBM, Bio-Oss Ò ; Geistlich Biomaterials) on the calvaria of rats. To model vertical bone augmentation, hemispherical cups were filled with the two types of biomaterial granules and implanted onto the skull of rats, while empty cups were used as controls. After 4 and 8 weeks of healing, bone growth was determined by microcomputed tomography and histomorphometry. After 4 weeks of implantation, a significantly higher bone growth was found in the case of SBCP compared with DBBM and left empty controls. At 8 weeks, no statistically significant differences were found between the two bone substitutes. These results are promising since vertical bone regeneration was faster in the case of SBCP than for DBBM.