## 3 Results  
The demographic description and the specialty of the 30 participants are presented in Table 1. The mean age of the inexperienced group (\(40.1\pm 7.5\)) was 5.4 years younger than the experienced group (\(45.5\pm 9.4\)). The experienced group had 6.7 years more of mean dental practicing years (\(20.1\pm 10.3\)) than the inexperienced group (\(13.4\pm 7.1\)); however, the differences were not significant. Only two of the dentists were female. All the participants used their right hand as the dominant hand (one dentist used to be left-handed, but he changed his dominant hand to the right hand). In the experienced group, almost half of the dentists came from the fixed prosthodontics and implantology department; four came from the oral and maxillofacial surgery department, and one from the periodontal department. However, more of the inexperienced dentists came from the other departments, including clinical cardiology, removable prosthodontics, and pediatric dentistry. The deviations between planned and placed implants for all of the implants in both of the experienced and inexperienced operator groups are presented and compared in Table 2. For all 90 implants, the mean global deviation was \(0.71\pm 0.39\) mm at the implant platform, and \(1.20\pm 0.87\) mm at the implant apex. The mean lateral deviation was \(0.50\pm 0.36\) mm at the implant platform, and \(1.06\pm 0.87\) mm at the implant apex. The mean depth deviation was \(0.41\pm 0.33\) mm, and the mean angular deviation was \(3.44\pm 3.00^{\circ}\). In the comparison between the experienced and inexperienced operator groups, no significant differences were found for any positional or angular deviations, even after adjusting the covariance between an individual operator and his experience. Except for the depth deviation, in which the mean value of the experienced operator group was almost the same as the inexperienced group (0.40 and 0.42 mm, respectively), the experienced operator groups had higher mean values of the other positional and angular deviations compared to the inexperienced operator groups (Table 2). \begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{2}{*}{**Operator**} & \multirow{2}{*}{**Dentist**} & \multirow{2}{*}{**Age**} & \multicolumn{2}{c}{**Gender**} & \multirow{2}{*}{**Years of**} & \multicolumn{3}{c}{**Speciality**} \\ \cline{3-4}  & & & **Male** & & **Female** & & **Practicing** & **Fixed Pros.** & **OS/Perio.** & **Others** \\ \hline Total & 30 & \(42.8\pm 8.8\) & 28 & 2 & 16.8 \(\pm\) 9.3 & 10 & 8 & 12 \\ (Range) & & (30–59) & & & (2–35) & & \\ Experienced & \(15\) & \(45.5\pm 9.4\) & 15 & - & 20.1 \(\pm\) 10.3 & 7 & 5 & 3 \\ (Range) & & (32–59) & & & (2–35) & & \\ Inexperienced & \(15\) & \(40.1\pm 7.5\) & 13 & 2 & 13.4 \(\pm\) 7.1 & 3 & 3 & 9 \\ (Range) & & (30–54) & & & (5–30) & & \\ \(p\) Value & & 0.1231 & 0.4828 & 0.0774 & & 0.0781 & \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Demographics and specialty of the participants. To examine the potential influence of different implant sites on the accuracy, all the positional and angular deviations were further evaluated according to each implant site group, and the results are presented in Table 3. Still, no significant differences were found between experienced and inexperienced operators for any of the measured deviations at the three implant sites, and most of the mean values of deviations of the inexperienced operator groups were less than the experienced groups. The distributions of the measured deviations for experienced and inexperienced operators are correspondingly presented in the box plots in Figures 7-9. Generally speaking, no significant disparity was observed between experienced and inexperienced operators in terms of the positional deviations at the implant platform (Figures 7a and 8a), and the depth deviations (Figure 9a) of each implant site.