The purpose of the study was to demonstrate bone regeneration and the time of formation of new alveolar bone based on implanted FlexiOss®Vet bone substitute material. The study attempted to determine the time taken to fill bone defects with newly formed osseous bone compared to alveoli with a standard method of filling the post-extraction alveolus with a collagen sponge. The study was conducted on a group of 12 dogs with advanced periodontal disease (stage IV) in which polymeric hydroxyapatite bone substitute material (FlexiOss®Vet) was implanted into alveoli on the right side, and collagen sponge was implanted into alveoli on the left side in the same patient. The patients underwent macroscopic inspection and X-ray examination at different periods of regeneration after the procedure. On the right side, macroscopically, the alveoli showed features of marked enlargement, and on X-ray examination they gave opacity to X-rays and there was no clear border between the alveolus and alveolar bone. On the left side, the alveoli were clearly penetrable to X-rays, and hollow alveoli filled mainly with connective tissue were observed. The study also showed a significant reduction in bone healing time in alveoli with implants compared to self-healing alveoli. These results suggest that the implanted material is significantly beneficial in the process of bone regeneration in large bone defects in dogs and notably shortens the process of bone regeneration after tooth extractions. It is presumed that this could reflect a model for the treatment of large bone defects in not only the maxilla and mandible, but also long bones, and that it could be a model for alveolar healing in humans.