a) First slice of the image stack. The red and blue boxes show respectively ROIs 1 and 2 used for further analysis. The dotted white line highlights the different regions, marked by the letters D: dentin and E: Enamel. Yellow dashed lines indicate the location of the orthogonal cuts (in the XZ plane) displayed in f) and g). Scale bar: 50µm. b) ROI 1 first slice. c) ROI 1 maximum intensity projection (MIP). d) ROI 2 first slice. e) ROI 2 MIP. b-e) Scale bar: 10µm. f-h) MIP over a limited number of slices (respectively 10, 9 and 17 slices) in sub-regions of ROIs. Scale bar: 5µm. i) XZ orthogonal cut close to the enamel. j) XZ orthogonal cut far from the enamel. i-j) Scale bar: 10µm. All images were contrasted (different values were used for each ROI) to enhance the visual perception of the structures.