## 3 Results  
A total of 108 single-tooth prostheses were successfully designed and milled with the five-axis milling device (M1, Zirkonzahn) for the 18 patients included in the study. All 18 anterior CAD-CAM rehabilitations could be successfully tried intraorally in both test groups (CAD and DENT), which used two software programs that have similar interfaces (i.e., DentalCAD and Zirkonzahn Modified). For this reason, no distinction or comparison between software programs was conducted herein. However, half of the CAD-CAM rehabilitations of the group DENT (n = 9) had at least one prosthesis requiring chairside adjustments of interproximal contacts to obtain adequate seating. In addition, 10 of the 18 rehabilitations of this group required occlusal adjustments due to excessive antagonist contacts. On the other hand, no chairside adjustments were required to obtain adequate seating of the restorations of the group CAD (Figure 3). The median and range of the Likert scale results for the three groups are available in Table 1. Group CAD significantly outperformed the other groups in both assessed variables (\(p\) = 0.001). The group DENT, in turn, significantly outperformed group CONTROL for satisfaction with esthetics (\(p\) = 0.006) but not for comfort (\(p\) > 0.05). In addition, the mean time required to perform digital waxing was 6.2 \(\pm\) 2.9 min for the CAD group and 10.2 \(\pm\) 3.1 min for the DENT group (\(p\) = 0.001 according to the Student \(t\)-test). On the other hand, there were no significant differences between time required using different software programs (\(p\) = 0.522). Qualitative analysis of the virtual wax patterns revealed that interproximal contours at the cervical third were the most challenging tooth anatomical landmarks to be satisfactorily designed and reproduced by the DENT group, as these were the main areas with decreased clinical esthetic outcomes, as compared to the CAD group. The second-most-challenging aspect of virtual waxing for the DENT group was the design of interproximal and antagonist contacts, which led to the necessity of performing chairside adjustments in several of the CAD-CAM crowns of this group, as explained above. Figure 2: Flowchart of the study design. Open-ended questions were qualitatively analyzed. The following trends were identified by the results: All 18 patients had previous experiences with conventional workflows involving impression materials, and all stated their preference to be treated with digital workflow involving digital impressions with intraoral scanners. All patients also stated that they were confident during the follow-up period of this study to bite with the anterior crowns installed. In addition, a total of 15 patients (83.3%) described that seeing the digital mock-up before even starting their CAD-CAM crowns (i.e., while the patients had their conventional temporary crowns) was important to make the decision to accept the proposed oral rehabilitation treatment plan (Figure 4). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Likert Scale Questions** &
\begin{tabular}{c} **Group** \\ **CONTROL** \\ \end{tabular} & **Group CAD** & **Group DENT** & \(p\) **Value \({}^{*}\)** \\ \hline Satisfaction with & 6 (4–8) & 10 (8–10) & 8 (7–10) & 0.001 \\ \hline Satisfaction with & 8 (5–10) & 10 (9–10) & 8 (6–9) & 0.001 \\ comfort & & & & \\ \hline \hline \end{tabular} \({}^{*}\)[PERSON]’s test. Bold font means statistically significant differences.  
\end{table} 
Table 1: Median and range of results and statistical differences between CAD operators designing anterior CAD-CAM rehabilations. Figure 3: Example of a case included in the comparison between groups CONTROL (initial situation with conventional temporary crowns), DENT (try-in of CAD-CAM prostheses designed by a dentist) and CAD (try-in of CAD-CAM prostheses designed by an experienced CAD-technician). Questionnaire results from all patients were obtained in the three treatment phases depicted above.