In recent years, calcium hydroxyapatite (HAp) and its substituents are increasingly used in dentistry and medicine. The influence of nanoparticles Ca / Co-HAp in strengthening weak osteoporotic bone jaw tegmenta was tested in an experimental model. The study was conducted on Wistar soy rats, aged 6-8 weeks. The biomaterial was implanted in the osteoporoticly weakened mandible of these animals. The best results in the strengthening of the lower jaw bone tegmenta were achieved 24 weeks after implantation of hydroxyapatite nanoparticles in which the calcium ion was substituted with 12% of cobalt ions. Histochemical parameters of bone synthesis were in a statistically significant increase. SEM analysis showed a high degree of osteogenetic ability of nano-particulate material implanted in the bone defect