## 2 Materials and Methods  
Based on the results of the power analysis (G*Power software v3.1.10, Heinrich Heine University, Dusseldorf, Germany), it was determined that at least 5 specimens were required in each group to achieve 95% confidence (1-\(\alpha\)), 95% test power (1-\(\beta\)), and an effect size of f = 0.57797. To ensure reliability, 10 specimens were prepared for each subgroup (\(n\) = 10). Each ceramic group was divided into two subgroups based on the surface treatment applied--mechanical polishing and glazing. In total, 104 specimens (\(n\) = 104) were prepared, comprising 20 samples for each CAD-CAM material for surface treatment protocols and 6 additional samples per material for SEM analysis. The materials used in the study are listed in Table 1.  
Three different lithium disilicate ceramics were used in the present study: CEREC Tessera blocks (CT) (Dentsply Sirona, York, PA, USA); GC Initial LiSi (LS) Block (GC, Tokyo, Japan); IPS e.max CAD (EC) (Ivoclar Vivadent, Schaan, Liechtenstein); and zirconia disc (KATANA (KAT)). All blocks were selected in A2 color, high translucency (HT), and C14 size. The blocks were cut with a thickness of 1.5 \(\pm\) 0.05 mm using a diamond cutting disc (Buehler Diamond Wafering Blade, Series 15 LC, Buehler, IL, USA) with a low-speed sectioning device (Isomet 1000, Buehler, Lake Bluff, IL, USA) and samples were prepared in accordance with the block dimensions (1.5 mm \(\times\) 12 mm \(\times\) 14 mm). Crystallization for EC was performed using the Programat P310 ceramic furnace (Ivoclar Vivadent, Schaan, Liechtenstein) following the manufacturer's instructions. The lithium disilicate blocks (LS and CT) were also crystallized. KATANA 5Y-PSZ monolithic zirconia (Kuraray Noritake, Tainai City, Japan) was used in this study, with a disc of 18 mm thickness and A2 color \begin{table}
\begin{tabular}{c c c c} \hline \hline
**Material** & **Product** & **Manufacturer** & **Lot Number** \\ \hline Lithium disilicate ceramic & IPS e.max CAD (EC) & \begin{tabular}{c} Ivoclar Vivadent, \\ Schaan, Liechtenstein \\ \end{tabular} & YB54 FL \\ \hline Lithium disilicate ceramic & CEREC Tessera (CT) & \begin{tabular}{c} Dentsply Sirona, \\ York, PA, USA \\ \end{tabular} & 16012436 \\ \hline Lithium disilicate ceramic & GC Initial LiSi (LS) & GC, Tokyo, Japan & 2107161 \\ \hline Monolithic zirconia & KATANA UTML (KAT) & \begin{tabular}{c} Kuraray Noritake, \\ Tainai City, Japan \\ \end{tabular} & EFJTM \\ \hline Mechanical polishing set used & G\&Z Instrumente/ & EVE Ernst Vetter GmbH, \\ for lithium disilicate ceramics & DPLT 14 RA Set & Birkenfeld, Germany & 473021 \\ \hline Mechanical polishing set used & G\&Z Instrumente/ & EVE Ernst Vetter GmbH, \\ for monolithic zirconia & DCAT 14 RA Set & Birkenfeld, Germany & 473724 \\ \hline Glaze paste and liquid used & IPS Ivocolor Glaze Paste & Ivoclar Vivadent, & Z038 YF \\ for IPS e.max CAD & IPS Ivocolor Mixing Liquid allround & Schaan, Liechtenstein & Z03 PP9 \\ \hline Glaze paste and liquid used & Universal Overglaze High Flu & \begin{tabular}{c} Dentsply Sirona, \\ York, PA, USA \\ \end{tabular} & 21002882 \\ for CEREC Tessera & Universal Stain and Glaze Liquid & \begin{tabular}{c} Dentsply Sirona, \\ York, PA, USA \\ \end{tabular} & 21002448 \\ \hline Glaze paste and liquid used & GC Initial IQ Lustre Pastes ONE/NF & \begin{tabular}{c} 2205021 \\ GC Initial IQ Lustre Pastes ONE \\ Diluting Liquid \\ \end{tabular} & GC, Tokyo, Japan & 2204111 \\ \hline Glaze paste used for & \begin{tabular}{c} Cerabien ZR FC Paste Stain Glaze \\ KATANA UTML \\ \end{tabular} & \
\begin{tabular}{c} Kuraray Noritake, \\ Tainai City, Japan \\ \end{tabular} & EJABU \\ \hline Diamond bur with fine grain &
\begin{tabular}{c} Hager \& Meisinger \\ GmbH, Neuss, Germany \\ \end{tabular} & R14777 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Materials used. selected based on the sample dimensions.