## 3 Results  
Table 3 illustrates the mean Pa values for the study group (mechanized polishing (6.04 \(\pm\) 5.45 \(\upmu\)m) and conventional polishing (4.27 \(\pm\) 4.74 \(\upmu\)m)) and for the control group (7.72 \(\pm\) 5.86 \(\upmu\)m), revealing a significant difference (\(p\) = 0.003, Kruskal-Wallis test). While the mechanized polishing yields higher roughness compared to the conventional polishing and the control group, both mean Pa values obtained from the mechanized and conventional polishing are significantly lower than those of the control group (Figure 2). Significant disparities emerged in the overall Pa values between the mechanized and conventional polishing techniques, with the mechanized polishing notably yielding higher roughness compared to the control group (6.04 \(\pm\) 5.45 \(\upmu\)m vs. 4.27 \(\pm\) 4.74 \(\upmu\)m; \(p\) = 0.004). Notably, the Pa values exhibited variations across different resin types, with self-cured and injected-molded resins generally manifesting higher values, while the 3D-printed and milled resins demonstrated lower values. Figure 2 allows an analysis of the distribution and dispersion of the roughness values. Neither the conventional nor the mechanized polishing techniques exhibited symmetrical distribution for any of the resin types. In terms of dispersion, the conventional polishing exhibited slightly higher dispersion compared to the mechanized technique, in contrast with the self-cured resin, where the mechanized polishing showed a slightly higher variability in Pa values. There is no discernible pattern, indicating that one polishing technique consistently showed higher dispersion across all resin types. Specifically, the self-cured (\(p\) < 0.001) and milled (\(p\) = 0.001) mechanized polished resins demonstrated significantly higher Pa values compared to the conventionally polished resins. However, no significant differences in irregularity Pa values were discerned in the subgroup analysis for the 3D-printed, injected-molded and heat-cured resins (Table 4). The analysis of roughness dispersion across various polishing techniques and resin types is presented in Table 5 and Figure 2. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Polishing Technique**} & \multirow{2}{*}{**Overall Pa (\(\upmu\)m)**, **Mean \(\pm\) SD**} & \multicolumn{4}{c}{**Resin-Specific Pa (\(\upmu\)m)**, **Mean \(\pm\) SD**} \\ \cline{3-6}  & & **Self Cured** & **3D Printed** & **Milled** & **Injected Molded** & **Heat Cured** \\ \hline Mechanized & 6.04 \(\pm\) 5.45 & 13.12 \(\pm\) 4.00 & 1.49 \(\pm\) 0.50 & 3.32 \(\pm\) 2.47 & 7.17 \(\pm\) 5.95 & 5.11 \(\pm\) 3.61 \\ Conventional & 4.27 \(\pm\) 4.74 & 5.46 \(\pm\) 5.51 & 1.49 \(\pm\) 0.50 & 1.44 \(\pm\) 1.08 & 8.93 \(\pm\) 6.23 & 4.01 \(\pm\) 2.58 \\ U statistics & 2051.500 & 28.500 & 111.000 & 29.000 & 223 & 93.000 \\ \(p\)-value & 0.004 & \textless{}0.001 & 0.950 & 0.001 & 0.443 & 0.419 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Roughness data (Pa/\(\upmu\)m) for polishing techniques and resin types. Figure 2: Distribution and dispersion of Pa/\(\upmu\)m with control group (SC—self cured, 3D—3D printed, M—milled, HC—heat cured, IM—injected molded). The mechanized polishing demonstrates relatively consistent skewness values across resin types, ranging from 0.51 to 1.49, suggesting a moderate concentration of material near the top of the profile and a plateau-like surface. However, the conventional polishing exhibits greater variability in skewness, with values ranging from 0.41 to 2.75. Particularly noteworthy is the conventionally polished milled group, which shows significantly higher skewness (2.75), indicating a more pronounced distribution of material with a longer tail towards higher amplitudes compared to other conventional techniques. Regarding kurtosis values, the mechanized polishing techniques generally exhibit low to moderate values, ranging from \(-1.04\) to 0.83, indicating a relatively balanced amplitude distribution with smaller peaks and valleys.