Fig. 7.

Scanning electron micrographs (Hitachi S-4700) of titanium screw (TiO₂) dip coated with 50 nm diameter gold colloids. At low magnification (×35), (a), the threads of the screw are visible. An area (white box in (a)) is investigated at sequentially increasing magnifications, (b), (c) and (d). At ×700, (b), the microtopography of the surface of the screw is prominent, but as the magnification is increased from ×11K, (c), to ×30K, (d), the colloidal nanotopography becomes visible. It should be noted that the colloids adhere to the pattern of the underlying titanium microtopography.