Description:
<p>This study examines the effects of several clinical procedures that lead to dehydration on color change in naturalteeth. CIE L*, a*, and b* color coordinates of maxillary incisors were measured using a spectrophotometer beforeand after the procedure at minute intervals of 10, 20, 30, and 1440 (24 hours). Test groups were as follows: 6 and15 minutes of the open mouth under LED and halogen dental reflectors; control groups were evaluated in a darkenvironment for 6 and 15 minutes; maxillary impressions were taken with condensation and additional typeimpression materials. Wilcoxon signed-rank tests and Mann–Whitney U tests were used for two-groupcomparisons. The analyses were computed by the Friedman and Kruskal–Wallis H tests for the paired andindependent groups. These tests were followed by Bonferroni posthoc corrections. Obtained color values indicatesignificant L* changes for all groups due to dehydration for 20 minutes after the procedure. Color changes (ΔE)were significant for 30 minutes for the perceptibility (1.2>ΔE) and 20 minutes for the acceptability threshold(2.7>ΔE). Results show that experimental protocols designed to mimic dental procedures that require mouthopening may cause temporary discoloration of natural teeth, which may cause failure during shade matching.<br></p>