Investigation of the distribution of cementum-associated lipopolysaccharides in periodontal disease by scanning electron microscope immunohistochemistry

Previous work in our laboratory has suggested that cementum-associated LPS is confined to the surface of affected roots. In order to localize the distribution of cementum-associated LPS more precisely, an immunogold/silver labelling system has been utilized to demonstrate LPS on scanning electron microscope images of scaled, extracted teeth. With this technique, antibody binding to the specimen is detected by electron probe X-ray microanalysis of the bound silver label. Most of the detectable LPS was found to be associated with bacteria and calculus which persisted on the root surface despite the scaling of the specimens. Smaller amounts of bound LPS were also detected on the cuticle and surface cementum layers of the affected root surfaces, but in places where some of the underlying cementum had been removed no LPS was detected. These results cast some doubt on the importance of the removal of cementum-bound endotoxins in the treatment of periodontal disease. From these results it is postulated that the principal therapeutic effect of extensive cementum removal by root planing is that it facilitates the removal of plaque and calculus from resorption lacunae, which were a prominent feature of the affected root surfaces.