Macrophage colonization of infected and non-infected dental tissues in vitro

Attachment and spreading of phagocytes on a mineralized tissue surface is crucial for their proper resorptive function. In other studies, attachment and spreading have been shown to be highly dependent on the nature and composition of the surface. In the present study, peritoneal macrophages were cultured on infected and non-infected mineralized and non-mineralized dental tissues, which were examined with scanning electron microscopy at different observation periods. Although some cells had attached to non-infected predentin, only a few showed signs of spreading, even after long incubation times. This contrasted with the behavior of macrophages cultivated on enamel, mineralized dentin and infected predentin. Most of these cells showed spreading and the characteristics of active, phagocytosing cells. The reluctance of macrophages to spread on non-infected predentin was suggested to be due to the non-mineralized nature of this tissue, although an influence of endogenous resorption inhibitors cannot be excluded.