The article is dedicated to the study of the efficacy of the periapical therapy of chronic periodontitis with the use of synthetic calcium-phosphate biomaterial. 30 patients aged from 22 to 56 years participated in a clinical study. Radiological evaluation was performed by radiovisiography and radiodensitometry. Follow-up examination was carried out at 3, 6 and 12 months. Densitometry indicators at the destruction site showed an increase in radiodensity from 74.2 ± 9.9 units (58.2%) to 111.9 ± 10.6 units (87.8%) after 12 months. Anterior group of teeth demonstrated statistically significant high rate of lesion compaction compared to posterior teeth.