The authors estimated the porous hydroxyapatite alloplasts in the treatment of periodontitis in a clinical and radiological way. The material has been used in 30 patients who had bone pockets deeper than 6 mm. Together, 46 bone pockets were filled. We obtained reduction of the depths of the pockets of 3.02 mm, decrease of the degree of the teeth mobility and the improvement of Engelberger, Marthaler and Raitetschak's radiological indicator by 13%. The results were compared with other works describing the usage of this material in stomatology. Basing on the literature the authors also presented the histological changes in periodontium tissues after the usage of tricalcium phosphate and compact and porous alloplastic hydroxyapatite ceramics.