Evaluation of a standard shade guide for color change after disinfection

Objective: To determine if surface disinfectants cause a change in the shade perception of a standard Classic Vitapan shade guide. Method and Materials: Consistency in shade selection for dental restorations involves many factors, and one of the most important is the shade tabs used in the selection process. Ten shade tabs each of shades B2, D2, C1, and A3.5 were selected from the Classic Vitapan shade guide (Vident). All tabs were measured with the EasyShade shade device (Vident) at baseline. Three tabs of each shade were set aside as controls. The other 7 tabs of each shade were treated with the surface disinfectant Cavicide (Metrex Research) for 480 cycles to simulate a year's usage. After each 480 cycles, all the tabs were again measured with the EasyShade. This process was repeated to simulate 2 and 3 years of use. Results: The data were analyzed to calculate the delta E 2000 for any change. A statistically significant increase was observed in the value (L*) and chroma (C*) after 2 and 3 years of simulated treatments. These changes were not perceptible to the clinician. Conclusions: The authors suggest that 1 standard shade guide be set aside to compare against those in clinical use to determine when they should be replaced. Keywords: delta E changes in shade tabs, shade guide, shade tab changes, surface disinfectants