The teeth colour was often determined optically, by colour key. The colour key is a type scale of approximately 16 units according to which the teeth colour is determined. Every person has his/her own individual colour which needn’t be the same on the whole tooth or all teeth, and it is very difficult to define with a colour key, especially under different light conditions. In ANDI-DENT, the colour is defined by a computer. We take an image of the tooth with a spatial computer where we get a scheme which can consist of x colours with specific instructions which colour is put on which part of the tooth. This way we achieve a perfect natural colour of the patient’s teeth.