Attachment of human gingival fibroblasts to planed root surfaces exposed to human plasma in vitro

We studied the effect of exposing planed dentin surfaces (DS) to human plasma on the attachment of human gingival fibroblasts (HGF) in vitro as compared with their attachment to citric-acid-demineralized DS. Sixty-six DS were prepared from root-planed roots of surgically extracted human third molars. In a pilot experiment 30 DS were demineralized in citric acid (pH 1.0 for 3 min), and each of 3 DS were placed in a culture dish and incubated with fresh plasma for 0, 10, or 30 sec, 1, 10, or 30 min, or 1, 1.5, 2, or 4h. In a second experiment, three culture dishes containing three DS each were assigned to each of four groups. These were untreated (control), incubated with plasma for 2h, acid-demineralized only, or acid-demineralized and then incubated with plasma for 2h. To each dish was added 0.2 X 10(6) HGF, and these were incubated for 2, 6, or 24 h. The unattached cells were then removed, and the DS fixed and processed for SEM. The results showed that exposing demineralized dentin surfaces to plasma causes the absorption of a coating layer, presumably of organic nature, as early as 30 sec after exposure. Acid-demineralized DS alone or together with plasma treatment enhanced both the attachment and the growth of HGF. However, treatment with plasma alone seemed to enhance the HGF attachment less than did acid demineralization alone.