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Aim: This study is aimed to evaluate the effect of staining solutions on the color stability of bulk fill and conventional nanohybrid resin composites (RCs) when subjected to various immersion periods. Materials and methods:A total of 120 cylindrical Teflon molds (4 × 4 mm) were obtained and divided into four groups of 30 each. Molds of groups I and II were filled with Tetric N Ceram Bulk Fill (Ivoclar Vivadent, Schaan, Liechtenstein) and Filtek Bulk Fill (3M ESPE, St. Paul, MN, USA). Molds of groups III and IV were filled with Tetric N Ceram (Ivoclar Vivadent) and Filtek Z250 XTE (3M ESPE) incremental fill RC. Photo-activation was performed and specimens were incubated. Spectrophotometer analysis was done according to Commission Internationale d'Eclairage Lab color scale. After taking the baseline measurements, 10 samples from each group were immersed in distilled water (control, subgroup a), tea (subgroup b), and coffee (subgroup c) respectively, for 1, 7, and 30 days. The color values of each specimen were remeasured and color change value (E*ab) was calculated after 1, 7, and 30 days. Data were analyzed by Friedman's test and Mann-Whitney U-test; p < 0.05 is considered to be statistically significant. Results:Group III specimens showed perceptible color changes at 30-day immersion period in coffee and tea. In group I specimens, color changes were perceptible at 7-and 30-day immersion periods in coffee and only 30-day immersion period in tea. Groups II and IV specimens showed perceptible color changes after all immersion periods in coffee and after 30 days in tea. Conclusion:It can be concluded that Tetric N Ceram has less color change than the other nanohybrid RCs investigated when immersed in coffee and tea after various immersion periods.

Have you ever had the problem of trying to determine what compression technique to use from which tool vendor and what to do if any of that changes during the design flow?This paper will present a DFT architecture and automation solution that provides flexibility for designs using scan compression.It combines generic and proprietary techniques to enhance testability, reduce design risk, and improve development time.Data and results for the use of this technique in a microprocessor chip will also be presented.