A new method to calculate the fractal dimension of surfaces: Application to human cell proliferation

This paper presents a new method of calculating the fractal dimension of su rfaces as well as a correction method which improved the results. To test i ts efficiency, the algorithms have been applied to stochastic surfaces of m athematical functions with known fractal dimensions and compared with the o scillation and the structure method. Better results have been found. This m ethod, called ANAM, has been used to characterize the roughness of orthopae dic metallic substrates (Ti6A14V alloy) in relation with human osteoblast a dhesion. It has then been shown that the fractal dimension parameters corre lated statistically with proliferation of cells, corresponding to a lower a dhesion on less organized surfaces. The significant correlation observed be tween fractal dimension parameters and cell adhesion therefore adds a new c oncept to substratum roughness influence on cell behaviour. (C) 2001 Elsevi er Science Ltd. All rights reserved.