The sintering properties of four established bioactive glasses and four novel glass compositions within the range of interest for bioactivity were studied. The sintering behaviour was evaluated using optical heating microscopy and DTA. Crushed glasses with different particle sizes were sintered into cylindrical bodies using several time temperature parameters. The porosity and the pore size were calculated from the cross sectional surfaces of the cylinders using SEM images. The composition of the crystals formed in heat treated glasses was studied by XRD and SEM/EDXA. Devitrification of the glasses started with either the crystallisation of Na2Ca2Si3O9 at around 650-700 degrees C or with the crystallisation of CaSiO3 at around 850-880 degrees C The composition of the primary crystalline phase formed in the glasses during heat treatment is decisive for the choice of glass composition for porous implants. Glass compositions forming CaSiO3 crystals are of interest for sintering purposes, as their devitrification temperature is high enough to allow viscous flow before devitrification. The maximum pore size of the implants increases with particle size whereas the total porosity was related to sintering temperature and time. The sintering parameters giving a desired porosity depend on the viscosity of the glass and thus, on its chemical composition.
|Julkaisu||European Journal of Glass Science and Technology Part a Glass Technology|
|Tila||Julkaistu - 2005|
|OKM-julkaisutyyppi||A1 Julkaistu artikkeli, soviteltu|