In order to make a custom dental drilling template, a single impression element is used that becomes a part of the later drilling template. To achieve this a guide-passage element is glued to the impression element. The exact position of the guide passage relative to the impression element prior to gluing is found by fixing both elements relative to each other on the same mounting plate using a periodic 2-D mounting structure. The passage element is mounted by an intermediate mounting element that is machined such that it carries the same or mating mounting structure according to positional data and that has a fitting area for fitting the guide passage to it.