Methyl methacrylate (MMA) is the basic component of bone cements. To use it, a dough is prepared from the liquid and powder by mixing right before application, which is normally done by the operating team. During its working phase, the dough is then inserted into the tissue where polymerization is completed. Thus, the final implant polymethyl methacrylate (PMMA) is only created at the implantation site. Besides methyl methacrylate, bone cements sometimes contain other methacrylates, such as butyl methacrylate. To achieve X-ray opacity, radiopacifiers like zirconium dioxide or barium sulfate are added to the powder. Both the liquid and powder components contain additives that launch polymerization and control the setting when mixed together. Moreover, softeners and emulsifiers are sometimes used. The addition of antibiotics to the powder component is intended to prevent infection.