Abstract
The rapid apatite conversion type calcium phosphate cement (RAC-CPC) becomes high alkalinity when stiffening, and it becomes neutral and shows no stimulation when it changes into hydroxyapatite. The purpose of this study was to evaluate the effects of RAC-CPC on the biological tissue and to evaluate the pH changes of RAC-CPC.
All of the agents (calcium hydroxide, a -TCP,1.7 RAC-CPC (Ca/P: 1.7) and 2.0 RAC-CPC (Ca/P: 2.0)) were applied to the dorsal subcutaneous tissue of rats and the pH values of tissue were measured. The pH changes of all of the agents themselves were also measured. The pH values were statistically analyzed using the Welch's t-test.
The results were as follows:
1) a -TCP kept the surface of dorsal subcutaneous tissue neutral.
2) Calcium hydroxide changed the surface of dorsal subcutaneous tissue to a status of high alkalinity for 2 days.
3) 1.7 RAC-CPC and 2.0 RAC-CPC kept their pH high alkalinity for 60 minutes.
4) 1.7 RAC-CPC and 2.0 RAC-CPC kept the surface of dorsal subcutaneous tissue at high alkalinity for 30 minutes and changed the tissue to neutral.
The biological tissue reacted maintain constancy in pH homeostasis by the action of blood and exudation liquid. Calcium hydroxide however, induced strong reaction to the biological tissue.
It was suggested that RAC-CPC has the ability to the dental pulp stimulates enough to induce the hard tissue formation.
