ABSTRACT
<p><b>OBJECTIVE</b>To investigate the influence of different intensity and directions of ambient light and adjacent tooth in anterior tooth color measurement by using colorimeter.</p><p><b>METHODS</b>Fiber lite MI-150 was used as ambient illuminant and it irradiated from three or twelve o'clock direction through 45 degrees angle above. The light magnitude 0, 50, 75, 100, 125, 150 W were applied in this experiment. The values of CIE L* a* b* were measured by Minolta Chroma meter CR-321 colorimeter on the center labial surface of ten extracted human maxillary central incisors with or without adjacent teeth, then those data were analyzed statistically by using SPSS 11.5.</p><p><b>RESULTS</b>Neither different intensities nor different directions of ambient light could influence the results of color measurement by using Minolta Chroma meter CR-321 colorimeter, so did the adjacent teeth whether those were exist or not.</p><p><b>CONCLUSION</b>There is no influence of ambient light and adjacent teeth in the color measurement of anterior teeth under this experiment condition, and Minolta Chroma meter CR-321 colorimeter can be used to measure the color directly aside the chair with light.</p>