[The accuracy of holograms compared to other model measurements]

Because holograms are easy to deal with, and because their information content is especially high, they will potentially play a much larger role in the future. In this study plaster casts were placed in a measuring device fabricated in our department, measured by means of a laser beam, and then the accuracy of these measurements was compared to hologram measurements taken by means of a sliding caliper. The result was that the computer-guided hologram measurements evidenced no significant differences with the measurements with a laser beam. The hologram measurements, which are regarded as having an accuracy of 0.182 mm, should therefore be significantly superior to sliding caliper measurements. When measuring the mesiodistal width of teeth, the caliper yields a pseudo-accuracy which doesn't correspond to the factual conditions. When defining the Z-coordinates, the sliding caliper's measuring deficiencies are easily circumvented, but this does not automatically imply a higher degree of accuracy.