SYNTHESIS and PROPERTIES of NON-RIGID CALCIUM PHOSPHATE CEMENT CONTAINING CHITOSAN

Calcium phosphate cement (CPC) has biocompatibility and osteoconductive property, but it has some drawbacks, such as wash-out and rigid and brittle properties. Such drawbacks can be overcome by fast-setting and gelation of the CPC paste. The CPC powder is a mixture of tetracalcium phosphate and dicalcium phosphate dehydrate. A low or medium molecular weight chitosan (lowor med-chitosan) and malic acid solution were used in the liquid phase to develop fast-setting and high work-of-fracture CPC materials. The incorporation of 1.25 2.5 wt% chitosan increased a tripled work-of-fracture to 12.0 kJ/m when not using chitosan. The setting time was 2.8±0.3 min and 5.5±0.5 min when 2.5 wt% lowor med-chitosan was used, respectively. The "non-rigid” and “fast-setting" CPC cement was successfully obtained by adding chitosan and malic acid to the liquid phase, and the incorporation of med-chitosan may produce a high work-of-fracture and stable CPC with a desirable setting time. (Received March 31, 2016; Accepted May 2, 2016)