Bone resorption is created by different etiological factors, such as tumors, infections, and trauma. When defects are too large and healing is not possible in a spontaneous way, the defect is called a critical size defect, which is defined as the smallest size of an intra-osseous wound that will not heal spontaneously during the lifetime of the individual. This study was conducted to evaluate the use of a mineralized plasmatic matrix versus bone graft alone or in the augmentation of bony cavities in animals. Ten adult male dogs ranging in age from 12 months to 18 months with a mean weight of ten kilograms were used in this study. Bone cavities were made in the tibia of each animal. The upper holes were implanted with a bovine bone material substitute the medial holes were implanted with a mineralized plasmatic matrix and the lower holes were left free from any implant material acting as control. The dogs were euthanized at 2, 4, and 6 weeks and prepared for H and E stain and trichrome stain. The healing process of bone cavities implanted with mineralized plasmatic matrix was better compared to cavities filled with bone grafts and those left to heal spontaneously. Mineralized plasmatic matrix facilitates graft application, in its stabilization, and improves cell penetration into the graft.