RESUMEN
<p><b>OBJECTIVE</b>To compare the shade matching accuracy between tabs of shade guide and tabs out of shade guide by prosthodontists.</p><p><b>METHODS</b>Sixty-two graduate students who had 1 to 5 years clinical experience without color blindness were included in this study. Twenty-nine tabs from Vita 3D-Master shadeguide and 7 tabs out of Vita 3D-Master shade guide but from Vita Bleachedguide 3D-Master were taken as the targets of shade matching and observed under the standard light. Subjects' shade matching accuracy on tabs of shadeguide and tabs out of shadeguide was recorded. Frequency of right match was analyzed using Monte Carlo exact probability-test. Wilcoxin test was used to analyze the difference between each group on ranked data of value, chroma and hue.</p><p><b>RESULTS</b>The shade matching accuracy of tabs of shade guide [45.9% (199/434)] was significantly higher than that of tabs out of shade guide [9.0% (39/434)]. There was significant difference between the two kinds of tabs of ranked data of value [0.2 (0.1 - 0.3), 0.4 (0.4 - 0.5)] and chroma [0.2 (0.1 - 0.4), 0.5 (0.4 - 0.6), P < 0.01, but there was no significant difference in hue data [0.3 (0.1 - 0.4), 0.3 (0.1 - 0.4)].</p><p><b>CONCLUSIONS</b>The shade matching ability of prosthodontists on tabs out of shade guide is lower than that on tabs of shadeguide. To fulfill clinical need, more training is necessary.</p>