The Law of Conservation of Mass dates from Antoine Lavoisier's 1789 discovery that mass is neither created nor destroyed in chemical reactions. In other words, the mass of any one element at the beginning of a reaction will equal the mass of that element at the end of the reaction.
Antibiotic Gentamicin, when mixed with DePuy Orthopaedics bone cement products, may weaken the bond between cement and bone in joint replacement patients, and cause the prosthetic to slide off of the bone after the patient has suffered a great deal of pain and immobility.
Definition of cement for Students. 1  1 : a powder that is made mainly from compounds of aluminum, calcium, silicon, and iron heated together and then ground and mixed with water to make mortar and concrete. 2  2 : 2concrete, mortar. 3  3 : a substance used to make things stick together firmly.