A study of the interface between bone and acrylic cement by scanning electron microscopy.

Under the scanning electron microscope, acrylic cement presents an external surface dotted with hemispherical protuberances and a cut surface of cancellous structure. The reaction of bone to acrylic has been studied, both in stable and unstable mechanical conditions. In the first instance, the bone tissue grows towards the cement with an osteogentic front that insinuates itself between the irregularities of the external surface and tends to infiltrate the apertures in it, producing a perfect anchorage which remains solid even after a long period of time. In the second instance, the contact between cement and bone is indirect, with an interposed layer of dense fibrous tissue, probably with a shock-absorbing function.