Fabrication of porous calcium polyphosphate implants by solid freeform fabrication: a study of processing parameters and in vitro degradation characteristics.

摘要: Solid freeform fabrication (SFF) involves the creation of a solid 3-D object desired shape by successively adding raw materials in particles or layers. Its use fabricating surgical implants is being explored. The objective this study was to determine feasibility using SFF build porous parts calcium polyphosphate (CPP), linear condensed phosphate that has been suggested as material for forming bioresorbable skeletal replacement implants. CPP powders (<25 microm particle size) were added an UV curable monomer (SOMOS 6110) at solids loading 25 vol %, with addition commercial dispersant prevent agglomeration and settling. Viscosity cure depth measurements performed insure suspension met requirements deemed necessary SFF. bulk cured sintered molds order assess binder removal sintering parameters. Using three-point bend test, ultimate bending strength energy-to-fracture samples simulating be formed strategy characterized. In vitro degradation studies 0.1M tris-buffered solution effect aging on mechanical properties function processing route resulting structures. polymer successfully removed from ceramic developing procedure combined slow heating rates low temperature dwells. Sintering 585 degrees C 1 h produced amorphous average porosity 27.7 +/- 2.0%. 600 crystalline having 22.9 1.3%. Crystalline found exhibit superior toughness compared CPP. Both experienced decline during degradation; however, effects more pronounced samples. Amorphous degrade four times faster than CPP, shown high levels present noticeable increase resistant attack dissolution limited surface features particles.