The effect of minocycline-HCl on diseased cementum in vitro

Objective To investigate the effects of minocycline-HCl on diseased cementum and on the attachment of human periodontal ligament (HPDL) cells to the conditioned root surfaces.Methods Cementum chips were obtained from roots exposed to periodontal pockets. After root planing, the chips were burnished with minocycline-HCl , and with saline burnishing as control. The root slices were divided into four groups, tow of those were placed in culture dishes with human periodontal ligament cells incubated for 24 hours. And then the media was removed and samples were fixed and processed for scanning electron microscopy (SEM). The surface morphology of cementum chips and HPDL cells were observed using SEM.Results Diseased root surfaces that were root planed revealed a flat, smooth surface, without smear layer. Mimocycline-HCl conditioned specimen showed a flat surface with numerous fiber-like structures, on which there was no smear layer. On Minocycline conditioned cementum surfaces, layered HPDL cells covered entirely the root chip surfaces at 24 hours. HPDL cells were flat, elongated with interconnected cytoplastmic extensions. The spreading of the cells make the contours of the cells hardly visible. On root planed alone surfaces, monolayer HPDL cells covered the root chips only partly at 24 hours. HPDL cells were flat with less spreading extensions. Cells were not as strong as that on minocycline treated root surface.Conclusion In view of morphology, minocycline-HCl conditioning causes demineralization of diseased cementum and exposes the collagen fibrils, which promote the attachment and growth of HPDL cells on the diseased root surface.