Adherence of Treponema denticola to modified hydroxyapatite

Small samples of hydroxyapatite (HA) beads were coated with 10 microL of either saliva, serum, human crevicular fluid, or a preparation of lysosomal enzymes from human polymorphonuclear leucocytes (PMN), before being added to suspensions of Treponema denticola. The beads were then observed with the scanning electron microscope. Abundant T. denticola were found to adhere to HA or HA coated with saliva, serum, or crevicular fluid. Coating the beads with lysosomal enzymes consistently prevented the adhesion of T. denticola. Adhesion of treponemes to hard surfaces, modulated by enzymes from PMNs, could represent a new virulence factor for these bacteria.