The presence of implant materials influences fibronectin arrangement and cell growth in fibroblast cultures.

The nature of the bone-implant interface has been much focused in investigating dental implant materials, whereas the relationship between implant and fibroblasts has received much less attention. To evaluate the biocompatibility degree of an implant material, both cell adhesion and cell growth must be tested in the presence of the implant. Four dental implant (A,B,C,D) made in titanium alloy and one of them (C) hydroxyapatite (HA)-coated in fibroblast cultures (48 and 72 h) were tested, by performing immunocytochemical techniques and then by observing fibronectin (FN) arrangement for cell adhesion and counting 5-bromodeoxyuridine (5-BrdU) to evaluate cell proliferation. Different FN arrangements were observed-i.e. organized in fibrils, or in focal adhesion plaques, as well as dispersed in the intercellular space-which varied for the different implants employed at the various culture stages. Equally, the per cent ratio of 5-BrdU positive cells was different, with a more significant increase (p < 0.001) between 48 and 72 h for implant C and the controls. It was observed that the higher percentages of 5-BrdU positive cells were in cultures where FN was organized mainly in focal adhesions, as well as 5-BrdU positive cells increased after 72 h in cultures, which after 48 h presented much FN dispersed in the intercellular space. It may be assumed that a correlation exists between FN arrangement and the percentage of 5-BrdU positive cells and that these two parameters vary in the presence of the different implants. Moreover, the HA-coated implant seems to be the most biocompatible in fibroblast cultures.