## 3 Results
### Surface Wear  
Comparing the pre and post surface conditions for wear, the outcomes revealed a significant difference in CC (0.003) and CN (0.042). 3D printing did not present any significant change in pre and post micro CT (0.141). The mean pre and post loading values noted for CC were 265.35 \(\pm\) 2.28 and 251.70 \(\pm\) 3.08 mm\({}^{3}\), and for CN, 294.98 \(\pm\) 3.35 (pre) and 277.19 \(\pm\) 3.29 mm\({}^{3}\) (post), respectively (Table 5 and Figure 3). Likewise, 3D specimens pre and post loading scans showed 218.30 \(\pm\) 1.43 and 207.49 \(\pm\) 2.28 mm\({}^{3}\) surface areas, respectively (Table 5). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline \multirow{2}{*}{**Study Groups**} & \multicolumn{2}{c}{**Mean Difference**} & \multirow{2}{*}{**SD \(\upmu\)m**} & \multirow{2}{*}{**Lower Bound \(\upmu\)m**} & \multirow{2}{*}{**Upper Bound \(\upmu\)m**} & \multirow{2}{*}{**ANOVA**} \\  & & **(I-J) \(\upmu\)m** & & & & \\ \hline \multirow{2}{*}{CC} & 3D & \(-2.33420\) * & 0.17674 & \(-2.7724\) & \(-1.8960\) & \\  & CN & \(-0.88760\) * & 0.17674 & \(-1.3258\) & \(-0.4494\) & \\ \hline \multirow{2}{*}{3D} & CC & 2.33420 * & 0.17674 & 1.8960 & 2.7724 & \\  & CN & 1.44660 * & 0.17674 & 1.0084 & 1.8848 & \\ \hline \multirow{2}{*}{CN} & CC & 0.88760 * & 0.17674 & 0.4494 & 1.3258 & \\  & 3D & \(-1.44660\) * & 0.17674 & \(-1.8848\) & \(-1.0084\) & \\ \hline \hline \end{tabular}  
* denotes significant difference, with \(p\) < 0.05 compared to the corresponding group in column 1 ([PERSON]’s post hoc test). CC: CAD-CAM, CN: conventional, 3D: 3D printing.  
\end{table} 
Table 4: Statistical comparison of the study groups for surface roughness. Figure 5: Mean surface micro-roughness of the specimens in the study groups. CC: CAD-CAM, CN: conventional, 3D: 3D printing. For surface wear (pre-post surface area), the highest mean value was noted in CN (17.79 \(\pm\) 2.78 mm\({}^{3}\)), whereas the lowest mean value was in 3D (10.81 \(\pm\) 2.00 mm\({}^{3}\)) (Table 5 and Figure 6). Comparatively, the average amount of surface wear observed in the CC group was 13.68 \(\pm\) 1.7 mm\({}^{3}\). Maximum surface wear observed among 3D, CN, and CC specimens was 19.91, 14.20, and 16.50 mm\({}^{3}\), respectively. Similarly, minimum surface wear observed among CN, CC, and 3D specimens was 7.8, 11.24, and 13.46, respectively. An overall significant difference among the study groups was observed (\(p\) = 0.01) (Table 5 and Figure 7). Table 6 presents a comparison of surface wear among the study groups. The values calculated showed a significant difference among the study groups (\(p\) < 0.01). The compari \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Study** & **Pre CL** & **Post CL** & **Mean Surface** & **Min** & **Max** & **ANOVA** \\
**Groups** & **(mm\({}^{3}\))** & **(mm\({}^{3}\))** & **Loss (mm\({}^{3}\))** & **(mm\({}^{3}\))** & **(mm\({}^{3}\))** & **(mm\({}^{3}\))** \\ \hline CC & 265.35 (2.28) & 251.7 (3.08) & 13.63 (1.72) & 11.24 & 16.50 & \\ \hline CN & 294.98 (3.35) & 277.19 (3.29) & 17.79 (2.78) & 7.8 & 14.20 & 0.01 \\ \hline
3D & \multirow{2}{*}{218.3 (1.4)} & \multirow{2}{*}{207.49 (2.28)} & \multirow{2}{*}{10.81 (2.00)} & \multirow{2}{*}{13.46} & \multirow{2}{*}{19.91} & \\ printing & & & & & & \\ \hline \end{tabular}
\end{table} 
Table 5: Surface wear among interim restorative samples in the study groups. CC: CAD-CAM, CN: conventional, 3D: 3D printing, CL: cyclic loading. Figure 6: Comparison of surface wear among the study groups using micro CT. CC: CAD-CAM, CN: conventional, 3D: 3D printing, CL: cyclic loading. Figure 7: Mean difference of surface loss among the study groups using the micro CT technique. CC: CAD-CAM, CN: conventional, 3D: 3D printing, CL: cyclic loading. son of CC with 3D and CC with CN specimens presented a mean difference of 2.82 \(\pm\) 0.99 and 4.15 \(\pm\) 0.99 mm\({}^{3}\), respectively.