Natural teeth are supported by connective tissue
collagen fibers that insert perpendicularly in the tooth cementum. Perpendicular insertion plays an important role in the maintenance of the junction between the oral epithelium and the periodontal connective tissue. Most
titanium dental implant surfaces have no micro or macro structure to support perpendicularly oriented
collagen attachment. Without this tight biologic seal to resist bacterial invasion and epithelial downgrowth, progressive bone loss in
peri-implantitis is seen around
dental implants. The purpose of this study was to establish the perpendicularly oriented
collagen attachment to
titanium oxide nanotube (
TNT), and to assess its binding stability.
TNT was prepared on the
titanium-surface by anodization. Scanning electron microscopy (SEM) showed a regularly aligned
TNT with an average 67 nm-diameter when anodized at 30 V for 3 h. Subsequently,
collagen type I (CoI) was electrophoretically fused to anodic
TNT in native
polyacrylamide gel system where negatively charged CoI-C term was perpendicularly navigated to
TNT. SEM and atomic force microscopy (AFM) were used to analyze CoI on the TiO2 and
TNT surface. Several
tens of nanometers of CoI protrusion were recorded by AFM. These protrusions may be long enough to be priming sites for cell-secreted CoI. CoI laid parallel to the
titanium surface when fused by a chemical linker. Binding resistance of CoI against drastic ultrasonication was measured by Fourier-transform infrared spectroscopy attenuated total reflection (FTIR-ATR). The electrophoretically fused CoI in the
titanium nanotube (
TNT-CoIEPF) showed the significantly greatest binding resistance than the other groups (P < 0.01, a 1-way ANOVA and Tukey HSD post hoc test). Furthermore,
TNT-CoIEPF surface rejected epithelial cell stretching and epithelial sheet formation. Chemically linked horizontal CoI on
titanium oxide (TiO2) facilitated epithelial cell stretching and sheet formation.