Ceramics-Silikáty 54, (4) 398 - 404 (2010)

The submitted work examined kinetics of formation of a newly formed phase of hydroxyapatite (HAp) on two synthetically prepared bone regenerating materials: β-tricalcium phosphate (TCP) and porous hydroxyapatite (HA). In vitro tests with simulated body fluid (SBF) were performed under a continual flow of fresh SBF solution in partly and fully filled testing cells. It has been found out that in the case of testing cells partly filled (¼ of the volume) with TCP and porous HA the contact between the material and SBF was better and thus also the precipitation of the new phase HAp was faster. The BET method identified a ten times increase of the (originally very small) TCP surface in both cases of cell filling, which indicates precipitation of the HAp phase. For porous HA the newly formed phase (HAp) cannot have been identified with SEM/EDS or RTG diffraction as its character was the same as that of the tested material. However, the BET analysis demonstrated a decrease in the size of the specific area of the porous HA after its exposure in the SBF solutions in both test arrangements, which indicates covering of the material surface with a newly formed HAp phase. Precipitation of the new phase was also confirmed by the increased weight of tested porous HA. The tested materials were not completely covered with the new HAp phase after 13 days of testing and their surface thus remained accessible for further resorption.