tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g...tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL -1 .The setting time could be adjusted,the maximum compressive strength was 45.36MPa,and the hydration product was hydroxyapatite (HAP).In vitro biological simulated experiments indicate that α TCP/TTCP bone cement has α certain dissolubility.The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks.The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response,no muscle stimulation,no haemolysis,no cruor,no inflammatory reaction and no exclusion response are caused by α TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging.α TCP/TTCP cement hydrated and hardened continually in vivo.The materials fused with host bone together with implanting time prolonging.Therefore,it is believed that α TCP/TTCP composite bone cement has a high biocompatibility and bioactivity,a certain biodegradation and good osteogenesis as well.展开更多
The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentratio...The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentration of 0.05?mol/L or higher. The relationship between the setting time of the system cement and the concentration of citric acid solution shows concave type curve. When solution concentration was 0.2?mol/L, the setting time was 8 min, which was the shortest. While the relationship between 24?h compressive strength of the cement and the citric acid concentration shows convex type curve. When solution concentration was 0.2?mol/L, the compressive strength was 39.0?MPa, which was the highest. Afterwards, the microstructure of the hardening product was observed by SEM, the effect of citric acid on the exothermic rate of hydrate reaction was studied by microcalorimeter, and the crushed specimens were subjected to X ray diffraction. The results verified that the low citric acid concentration can accelerate the hydrate reaction rate of the α TCP/TTCP system. However, the high citric acid concentration inhibited hydroxyapatite formation and retarded the rate of hydrate reaction of the α TCP/TTCP cement.展开更多
文摘tricalcium phosphate(α TCP)/tetracalcium phosphate(TTCP) composite bone cement had good hydration characteristic.In our system,α TCP/TTCP powder mixture was mixed with water at a powder/liquid (P/L) ratio of 1.50g·mL -1 .The setting time could be adjusted,the maximum compressive strength was 45.36MPa,and the hydration product was hydroxyapatite (HAP).In vitro biological simulated experiments indicate that α TCP/TTCP bone cement has α certain dissolubility.The hardened product is mainly HAP after soaking in simulated body fluid (SBF) for 10 weeks.The results of in vitro test and animal experiments and SEM analyses show that no local or general toxicity response,no muscle stimulation,no haemolysis,no cruor,no inflammatory reaction and no exclusion response are caused by α TCP/TTCP cement, which can be contributed to bone tissue spreading and impinging.α TCP/TTCP cement hydrated and hardened continually in vivo.The materials fused with host bone together with implanting time prolonging.Therefore,it is believed that α TCP/TTCP composite bone cement has a high biocompatibility and bioactivity,a certain biodegradation and good osteogenesis as well.
文摘The properties of calcium phosphate cement consisting of α tricalcium phosphate ( α TCP) and tetracalcium phosphate (TTCP) have been investigated by using a cement liquid that contained citric acid with concentration of 0.05?mol/L or higher. The relationship between the setting time of the system cement and the concentration of citric acid solution shows concave type curve. When solution concentration was 0.2?mol/L, the setting time was 8 min, which was the shortest. While the relationship between 24?h compressive strength of the cement and the citric acid concentration shows convex type curve. When solution concentration was 0.2?mol/L, the compressive strength was 39.0?MPa, which was the highest. Afterwards, the microstructure of the hardening product was observed by SEM, the effect of citric acid on the exothermic rate of hydrate reaction was studied by microcalorimeter, and the crushed specimens were subjected to X ray diffraction. The results verified that the low citric acid concentration can accelerate the hydrate reaction rate of the α TCP/TTCP system. However, the high citric acid concentration inhibited hydroxyapatite formation and retarded the rate of hydrate reaction of the α TCP/TTCP cement.
