Bone morphogenetic protein is an isolated protein that induces specific cells in our body to form new cartilage and bone. During surgery, the BMP is soaked onto and binds with a collagen sponge. The sponge is then designed to resorb, or disappear, over time. As the sponge dissolves, the bone morphogenetic protein stimulates the cells to produce new bone. The BMP also goes away once it has completed its task of jump starting the normal bone healing process.