## 3 Results  
The means and standard deviations for surface roughness at baseline, before and after complete crystallization of the samples of lithium disilicate (LDS) and zirconia-reinforced lithium silicate (ZLS), are presented in Table 4.  
The one-way ANOVA revealed a statistically significant difference in the mean 3D roughness values between the baseline groups (see Table 5). The Tukey multiple comparisons test, applied at the 0.05 significance level, was used to determine the statistical differences (\(p<0.05\)) between LDS and ZLS, both before and after crystallization. The CAD milling process led to a notable increase in surface roughness post-removal from the MC XL milling machine (Dentsply Sirona), establishing the baseline for both materials (\(p\,\leq\,0.05\)). At this baseline, ZLS exhibited overall lower surface roughness levels than LDS (\(p\,\leq\,0.05\)). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & \multicolumn{6}{c}{**Areal Roughness (Sa)**} \\ \cline{2-6}  & \multicolumn{3}{c}{**IPS EMAX CAD**} & \multicolumn{3}{c}{**VITA SUPRINITY PC**} \\ \hline
**Groups** & **Mean** & \(\pm\)**SD** & **Mann–Whitney U** & **Mean** & \(\pm\)**SD** \\ \hline
1 & 1.225  & 0.083 & 132.0 (\(p\) = 0.0000555) & 0.967  & 0.048 \\ \hline
2 & 1.107  & 0.116 & 144.0 (\(p\) = 0.0000364) & 0.630  & 0.044 \\ \hline
3 & 0.017  & 0.003 & 17.0 (\(p\) = 0.0016) & 0.025  & 0.005 \\ \hline
4 & 0.019  & 0.004 & 123.0 (\(p\) = 0.0033) & 0.014  & 0.003 \\ \hline
5 & 0.016  & 0.005 & 12.0 (\(p\) = 0.000576) & 0.024  & 0.006 \\ \hline
6 & 0.019  & 0.003 & 126.0 (\(p\) = 0.0018) & 0.013  & 0.002 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Mean and standard deviation of Sa (arithmetic mean height) values of all groups and the Tukey HSD significance test. Values with different letters were significantly different from each other (\(p<0.05\)). The Mann–Whitney U test was used to compare the distributions of the two independent materials, with \(p<0.05\) values for all groups. In the comparison within the same material, LDS showed slightly smoother values after the crystallization process; however, the difference in the mean surface roughness (Sa) values before and after the final firing cycle was not statistically significant. Conversely, ZLS experienced a significant reduction in surface roughness following the final crystallization process, even without any polishing procedure (\(p\leq 0.05\)). The statistical analysis via one-way ANOVA confirmed that all polishing procedures enhanced the smoothness of the surfaces of the high-strength silicate ceramics under study (\(p\leq 0.05\)). To identify statistically significant differences between the polishing sequences and between the materials, [PERSON]'s test with multiple comparison was employed at the 0.05 significance level. The results, including the means, standard deviations, and statistical significance of surface roughness before and after final crystallization, are detailed in Table 4.  
For lithium disilicate (LDS) samples, one-way ANOVA revealed that the differences in polished surface roughness (Sa) values before and after crystallization and in between the two different polishing systems were not significant at the level of 0.05 (refer to Figure 4). The omnibus test of differences across the four categories indicated no significant difference (\(p=0.129\)), rendering a subsequent Tukey test unnecessary for this material. In contrast, for zirconia-reinforced lithium silicate (ZLS), the one-way ANOVA demonstrated significant differences among the four groups. A Tukey test with multiple comparisons was conducted (\(p\leq 0.05\)). It was found that surface roughness values were significantly reduced when polishing occurred after the final crystallization of ZLS blocks (\(p<0.001\)). However, no significant differences were observed when comparing the effects of the Vita Suprinity and Brasseiler polishing systems, both before (\(p=0.910\)) and after (\(p=0.968\)) crystallization, on the mean surface roughness (Sa) values (see Figure 5).