complex and the reference template 10 in fig1 can be considered more simple of course instead of using the deep dentine material 18 for the reference template in fig2 it is also possible to use clear material which results in a more translucent effect another reference template 10 can be seen in fig3 it has a minimum overall layer thickness of only 0 66 mm provided in this case is a combination of 0 12 mm enamel material 12 0 4 mm dentine material 14 and 0 08 mm opaque layer 16 it is obvious that as suitable materials are developed in the future that are appropriate for even thinner layer thicknesses these can also be prepared and analyzed as reference templates in accordance with the invention the reference templates are preferably analyzed in the same manner that the patient 39 s teeth are later analyzed provided for this is a covering sheath 20 illustrated in fig4 that is black in color on the inside and that has a recess 22 that substantially corresponds to the labial or buccal view of a tooth the recess 22 is embodied in an end 24 of the sheath that is black on the inside while the digital camera not shown is attached to the opposing end such a covering sheath 20 not only fulfills the function.