Abstract
The purpose of the study was to evaluate the effect of a chemical disinfectant on the colors of TetricARG N-Ceram shade guide tabs after 1, 2, and 3 years of simulated treatments. Ten shade tabs (1, control; 9, for disinfection) were evaluated for color changes, visually and by chromametry, after disinfection in a simulated treatment. Results showed that IE was statistically significantly increasing with time (from year 1 to year 3) reaching to 0.58 units after 3 years of disinfection. The color changes were visually perceptible or noticeable in 15.6% of shade guide tabs (7 out of 45 tabs) after 2 years and in 24.4% of shade tabs (11 out of 45 tabs) after 3 years of treatment. It was suggested that one shade guide should be kept as a control and periodically compared with the shade guide in use, to determine when the shade tabs in use should be replaced or discarded.