[How precise is the optical Cerec impression?]

The purpose of this investigation was to evaluate the precision of optical impressio obtained with the Cerec-device. Cerec provides a linear correlation between z-data and altitude (r = 1), one bit representing 49 microns. Repeated measurements deliver pixel-z-data within a range of +/- 49 microns and surfaceaverages (484 pixel) within +/- 5 microns. Deviations occur near areas with parallel orientation to the direction of measurement.