REPEATABILITY OF A SPECIALLY DESIGNED INTRAORAL COLORIMETER

A specially modified Minolta CS-100 colorimeter with a DP-101 data pro cessor was designed for intraoral use. To test the repeatability of th e results obtained with this specially modified unit, five porcelain a nd five acrylic resin denture teeth were mounted in a fixed position i n front of a fixed mounted meter. Three La*b* readings were taken per tooth and mean values were obtained after calibration as a baseline m easurement. The readings were repeated on day 3 without recalibration and on day 8 after recalibration. The same-day repeatability showed DE LTAE values <0.4 in nine of the 10 samples. The day 3 repeatability sh owed DELTAE values <0.4 in only 2 of the 10 samples. The day 8 results , after recalibration, showed DELTAE values >0.4 in all of the samples , with a range of 0.57 to 2.75. In vivo testing was performed on five patients with DELTAE values that ranged from 1.1 to 32.1.