Methods: Two materials with the same color (“burnt orange”) were compared: Express Putty STD, EPS (hand mix, 3M ESPE) and Express 3 Penta Putty Soft, EPPS (dynamic mix, 3M ESPE).
Three people generated three samples of mixed EPS (30 second mix according to the instructions for use). Three comparative samples of EPPS were generated using the Pentamix 3. All samples were investigated twice using a spectrometer (Ocean Optics, S2000) and a lens system enabling a spacial resolution of 0.1mm after setting. The samples were moved in the focus of the lens system on a zigzag course in an area of 2x8mm by two linear axes. During the movement, the a-value of the Lab color system was recorded by a data logger. The standard deviation of the a-value of each sample is used as the metric for mixing quality.
Results: The standard deviation for the color value for each group of samples was (mean, SD in brackets): EPS: 2.536 (1.808) and EPPS: 0.227 (0.012). As shown by ANOVA (p<0.05) the standard deviation of the color value of EPS is significantly higher than that of EPPS.
Conclusion: When comparing the deviation of the color value, the products tested showed a more homogenous mix after dynamic mixing (EPPS) as compared to hand mixing (EPS).