Effect of bone sialoprotein and collagen coating on cell attachment to TICER® and pure titanium implant surfaces

To improve integration between implants and biological tissues, this study compared bone sialoprotein (BSP) as a surface-coating material against the major organic and inorganic components of bone, collagen type I and hydroxyapatite (TICER®). The expression of osteocalcin, osteonectin and transforming growth factor ß was evaluated using immunohistochemical staining procedures. The distribution patterns of osteoblasts on the surface of pure titanium with a smooth machined surface and a rough surface (TICER®) were determined by image processing using confocal laser scanning microscopy.The results compared to uncoated control materials showed that, at all times investigated, the number of cells on the surface of the TICER® and pure titanium samples differed significantly (P < 0.1), demonstrating the superiority of TICER® over pure titanium in this respect. For pure titanium implants, collagen-precoated surfaces were not beneficial for the attachment of bone-derived cells with the exception of day 3 in vitro (P < 0.01). BSP-precoated implant surfaces displayed non-significantly higher numbers of settled cells. BSP-precoated implant surfaces were beneficial for osteoinduction as revealed by osteocalcin and osteonectin expression. BSP precoating of the rough TICER® implant surface enhanced the osteoinductive effect much more than did collagen precoating. These results contribute to the consideration of at least two distinct pathways of osseointegration.