The mechanical properties of "cement-antibiotic" mixtures

The authors investigated the mechanical properties of "CMW cement-antibiotic" mixtures compared with those of the standard preparation. They carried out comparative tests of tensile strength, hardness and flexion (flexion breaking load, percentage flexion, modulus of elasticity to flexion). The antibiotics used were: streptomycin, ampicillin, cefalotin, carbenicillin, rifampicin, kanamycin, gentamycin and tobramycin. The mechanical tests performed showed that the percentage reductions in the strength of the mixtures varied considerably depending on the type of antibiotic used. The reductions produced by antibiotics used in aqueous solution (gentamycin and tobramycin) were excessive. The results obtained with the other mixtures were much better; in particular, some of the values obtained with the CMW cement-cefalotin and CMW cement-streptomycin mixtures were very close to those for the standard preparation. The combination of rifampicin with CMW cement, on the other hand, prevented complete polymerization of the cement.