A settable osteostimulative bone graft putty composition having a bioactive glass particulate component composed of a long-term and a short-term component; the long-term component having particle sizes greater than 90 micrometers and the short-term component having particle sizes less than 90 micrometers; the long-term component comprising about 60% to 90% of the bioactive glass osteostimulative particulate component dry weight and the short-term component comprising about 40% to 10%; a binder component having a calcium sulfate component and a calcium silicate component; the calcium sulfate component comprising about 35% to 50% of the binder component dry weight and the calcium silicate component comprising about 65% to 50%; the bioactive glass osteostimulative particulate component being about 20% to 60% of the total putty dry weight composition and the binder being about 80% to 40%; the bioactive glass particulate component and the binder component mixable in water to form the putty.