## 4 Discussion
Methacrylate material was shown to produce a smoother surface due to its composition compared to bisacrylates. These materials are composed of smaller filler, which influences the polishability of the material to produce a smooth surface [8]. Hence, using methacrylates for interim restoration is a safer option because these materials do not contain filler particles, which do not correlate with surface smoothness. In addition, these materials respond better to the polishing techniques, resulting in homogenous and void-free surfaces [10]. Furthermore, the difference in the process of each technique greatly influenced the surface roughness of the restoration. Conventionally, hand mixing involves human error and lack of precision due to defects in the model impression [8,24]. This causes uneven and increased surface roughness. In contrast, using a milling machine and 3D printer enhances the output because of the accuracy and precision of the software [25,26]. However, the present study showed a comparable outcome for the conventional and 3D-printed specimens, while CAD-CAM presented with the least surface roughness. [PERSON] et al. (2018) showed that using the layering technique in 3D printing leads to defects in the surface as the 3D printer only uses one bar at a time (as several bars do not adhere during the process), which leaves laminated lines and lower reproducibility, thus indicating the technique to process plays an important role in the smoothness of the surface rather than the material used. Moreover, a positive correlation was observed in the present study between adaptation and surface roughness except through the conventional method and marginal misfit. According to [PERSON] et al. (2018), the accuracy of a 3D printer depends upon proper printing orientation [13]. The distance, maintained at 25 mm, was identified to reduce the risk of error in the perfect dimensions of the restoration. The outcomes of [PERSON] et al. 's (2018) study suggested that orientation at 90\({}^{\circ}\) had the lowest percent error, followed by those printed at 0\({}^{\circ}\), 15\({}^{\circ}\), and 45\({}^{\circ}\) (\(p\) < 0.05) [13]. Hence, a higher change in dimension at 0-degree orientation significantly decreased with a change in the 15\({}^{\circ}\), 45\({}^{\circ}\), and 90\({}^{\circ}\) orientation groups accordingly. In contrast, a study by [PERSON] et al. (2019) showed that the orientation has a positive effect on the final performance of the restoration because of its anisotropic nature [27]. He assumed that the same layer produces more adhesion compared to different layers; however, other studies have opposed the idea with the theory of suggestive polymerization [27]. Hence, maximum polymerization at a 90-degree orientation improves the mechanical strength far more than a 0-degree orientation. In the oral cavity, the process of material setting and hardness value varies under the influence of multiple factors, including mechanical, thermal, and chemical reactions [28]. Many authors have reported that opposite condition load, surrounding medium, and material composition play a vital role in the surface wear of the restoration [28,29]. In the present study, before the cyclic loading, the highest surface roughness was observed in the conventional technique, followed by CAD-CAM and 3D printing techniques. After performing the cyclic loading, a greater amount of wear was apparent in the conventional and CAD-CAM techniques, whereas the 3D-printed specimens showed no significant changes in surface wear. This indicates the superior efficacy of the fabrication technique in producing a smooth and fine surface for the interim restoration. Moreover, some authors believed that material composition was the main variable affecting the quality of surface wear rather than technique [14; 30]. [PERSON] et al. demonstrated that toothbrush abrasion was more apparent in methyl methacrylate restorations rather than bisacryl restorations [16].