The present invention relates to an implantable paste comprising bioactive glass powder having a size distribution of 0.5-45 µm, bioactive glass granules having a size distribution between 100 and 4000 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. The composition of the bioactive glass is 45-55 weight-% of SiO 2 , 20-25 weight-% of Na 2 O, 18-25 weight-% of CaO and 3-6 weight-% of P 2 O 5 , and 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.
