The intent of this project was to evaluate whether or not there exists a correlation between fractal dimension, surface roughness, and fracture toughness of an unfilled resin and a filled composite. The fracture surfaces of the unfilled resin and the filled composite were examined using atomic force microscopy (AFM) and a surface roughness measuring device. The specimens examined were aged in distilled water or air at 37°C for up to 12 months. Line scans of 1.4 µm for the atomic force microscope and 0.25 mm for the surface analyzer across the fracture surface were conducted on each specimen. Comparisons were made between the fracture toughness (KIc) of the specimens, the fractal dimensional increment (D*), and surface roughness (Ra). No correlation was found.
Drummond, James L.
"Fractals, Surface Roughness, and Fracture Toughness of Dental Composite and Unfilled Resin Fracture Surfaces,"
Cells and Materials: Vol. 7
, Article 2.
Available at: http://digitalcommons.usu.edu/cellsandmaterials/vol7/iss2/2