Rheological Properties of Calcium Phosphate Cement

Objectives:The purpose of this study was to investigate the rheological properties of calcium phosphate cement (CPC) paste mixed with 2 kinds of setting solution, hydroxyprophyl methylcellulose(HPMC) and polyacrylic acid(PAA).

Methods:The calcium phosphate cement used in this study was Dicalcium phosphate dehydrate(DCPD, Riedel de Hann, Germany). The calcium phosphate cement powders were used to prepare pastes with 2 different setting solutions, sodium phosphate solution(0.05M/L) with HPMC(2%) and PAA solution(35%)

Complex viscosity(ç*) of the CPC pastes were measured with a rheometer. (AR-G2, TA instrument, New catle, Delaware, USA).

Results:The result of frequency sweep test presented property of shear thinning.

The result of time sweep test demonstrated that Complex viscosity(ç*) increased with hydration time, which shows the hardening reaction of the CPC paste. Complex viscosity of CPC with HPMC was higher than that of CPC with PAA.

Conclusions:The CPC paste with both setting solutions presented shear thinning, and hardening with time.