The present invention relates to an implantable paste comprising bioactive glass spheres having a size distribution of 50-425 μm, low molecular weight polyethylene glycol having a molecular weight range of 200-700 g/mol, medium molecular weight polyethylene glycol having a molecular weight range of 700-2500 g/mol and high molecular weight polyethylene glycol having a molecular weight range of 2500-8000 g/mol, with the proviso that the molecular weight of the low molecular weight polyethylene glycol and of the medium molecular weight polyethylene glycol differ from each other by at least 80 g/mol and that the molecular weight of the medium molecular weight polyethylene glycol and of the high molecular weight polyethylene glycol differ from each other by at least 300 g/mol.
