# Air-Polishing Powders' Effect on the Color of CAD/CAM Restorative Materials
## 2 Materials and Methods  
Five different types of CAD/CAM blocks were tested in this study. A glass-ceramic, namely, Vitablocs Mark II (VM) (feldspar ceramic; Vita Zahnfabrik H. Rauter, Bad Sackingen, Germany); resins with scattered fillers, namely, Paradigm MZ 100 (MZ) (resin composite; 3M ESPE, Seefeld, Germany), Lava Ultimate (LU) (resin nanoceramic; 3M ESPE, Seefeld, Germany), and Cerasamart (CS) (flexible hybrid ceramic; GC Corp., Alsip, IL, USA); and a polymer-infiltrated ceramic network, namely, Vita Enamic (VE) (polymer-infiltrated ceramic network; Vita Zahnfabrik H. Rauter, Bad Sackingen, Germany) were analyzed. The comprehensive information on these blocks is exhibited in Table 1. A flow chart of the study design is shown in Figure 1.  
The sample size was calculated with power analysis using G*Power software (Version 3.1; University of Dusseldorf, Dusseldorf, Germany). The effect size (d) was taken as 0.606, and the standard deviation value for \(\Delta\)E was taken as 1, so the number of samples, determined for power: 0.80 and \(\alpha\): 0.05, was calculated as minimum n = 6 for each group, related to a previous study [34]. Fifty samples of 1.1 mm thickness were prepared from each CAD-CAM block with diamond disks using a slow-speed precision cutter (Mecanome T180, PRESI, Eybens, France). All specimens were polished with a polishing machine (Mecatech 234 TCI-10, Presi, Eybens, France) and ground to the final thickness of 1 mm with waterproof abrasive papers from 320 to 2000 grits. Then, the samples were further polished for 180 s with the same machine, in accordance with the manufacturer's instructions, at a constant speed of 150 rpm clockwise and 30 rpm counterclockwise, with a pressure of 3.00 daN, using a blue polishing felt (PRESI, Reflex Concept Pad Mag, Eybens, France) and a 0.50 mL drop of diamond polishing solution (PRESI, Preparations Diametees Mecaprex, Eybence, France) every 10 s. The final thicknesses of the specimens were checked with a digital micrometer (C-master; Mitutoyo, Japan). Then, the specimens were cleaned in distilled water with an ultrasonic cleaner (Eurosonic Energy; Euronda SpA, Vicenza, Italy) for 10 min and dried with oil-free air for 30 s. After the CAD/CAM blocks were randomly divided into five groups (n = 10) for air-polishing with different APPs, the color measurement of each specimen was performed. \begin{table}
\begin{tabular}{c c c c c} \hline
**Material and** & **Batch** & **Type** & **Shade** & **Composition** \\ \hline Vitablocs Mark II (VM); & 35360 & Feldspar ceramic & A2 & Fine-particle feldspar ceramic (4 \(\mu\)m). \\ \hline Paradigm MZ 100 (MZ); 3M ESPE & N543696 & Resin composite & A2 & \begin{tabular}{c} Bis-GMA, TEGDMA. \\ Filler: zirconia–silica particles (0.01 to 3.5 \(\mu\)m), \\ 85\% by weight. \\ \end{tabular} \\ \hline Lava Ultimate (LU); 3M ESPE & N593972 & Resin nanoceramic & A2 & \begin{tabular}{c} Bis-EMA, Bis-GMA, TEGDMA, UDMA. \\ Filler: ZrO\({}_{2}\) (4–11 nm) and SiO\({}_{2}\) (20 nm), \\ aggregated zirconia/silica cluster filler, 80\% by weight. \\ \end{tabular} \\ \hline Cerasamart (CS); & 1408011 & Flexible hybrid ceramic & A2 & \
\begin{tabular}{c} Bis-MEPP, UDMA, Dimethacrylate. \\ Filler: SiO\({}_{2}\) (20 nm), barium glass (300 nm), \\ 71\% by weight. \\ \end{tabular} \\ \hline Vita Enamic (VE); & 42821 & Polymer-infiltrated ceramic network & A2 &
\begin{tabular}{c} TESDMA, UDMA. \\ Filler: feldspar ceramic enriched with \\ aluminum oxide, 86\% by weight. \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 1: CAD/CAM blocks used in this study.