Fabrication of biporous low-crystalline apatite based on mannitol dissolution from apatite cement.

Biporous (macro- and microporous) calcium phosphate gains much attention as a bone substitute material because of its large surface area and that it improves cell penetration. In the present study, we evaluated the feasibility of biporous, low-crystalline apatite based on dissolution of mannitol from self-setting apatite cement (Biopex). Mannitol--known as a biocompatible, easily dissolved monosaccharide alcohol--was recrystallized to obtain larger crystals.

Effects of added sodium alginate on mechanical strength of apatite cement.

Effects of added sodium alginate on the mechanical strength of Biopex, one type of apatite cement, were investigated since sodium alginate addition is very effective for Biopex to acquire anti-washout property. Addition of sodium alginate into the liquid phase of Biopex resulted in a slower transformation to apatitic monolith. As a result, mechanical strength of set Biopex in terms of diametral tensile strength (DTS) decreased when it was hardened in an incubator kept at 37 degrees C and 100% relative humidity for 7 days.