CALCIUM-PHOSPHATE CEMENT - IN-VITRO AND IN-VIVO STUDIES OF THE ALPHA-TRICALCIUM PHOSPHATE-DICALCIUM PHOSPHATE DIBASIC-TETRACALCIUM PHOSPHATE MONOXIDE SYSTEM

In this paper, calcium phosphate cement consisting of alpha-tricalcium phosphate (alpha-TCP), dicalcium phosphate dibasic (DCPD) and tetraca lcium phosphate monoxide (TeCP) was investigated in vitro and in vivo. Measurements of compressive strength against soaking time in simulate d body fluid (SBF) showed a rapid increase of the hardness for the fir st 7 days. The gained strength was retained up to 1 year and the maxim al mean value was 94.7 (+/-14.4) MPa. X-ray diffraction (XRD) and scan ning electron microscopy (SEM) presented precipitates of hydroxyapatit e (HA) after mixing, also after soaking in SBF and after implantation in rat subcutaneous tissues. However, the conversion to HA happened in different ways between in vitro and in vivo exposures. Histologic exa minations showed that the cement causes the same reactions at the;inte rface with surrounding soft tissues as HA. The authors consider the ce ment to be a promising material as a bone substitute, bone cement or d ental material, however, further studies in a paste form and in bone t issue environments are necessary.