## 3 Results  
The results of the repeated-measure analyses of variance followed by univariates analyses and Bonferroni multiple comparisons tests for trueness are shown in Table 1 and Figure 6 and for precision in Table 2 and Figure 7.  
Figure 6: Trueness of intraoral scan bodies in terms of 3D deviation. RMS, root mean square; ISBs, intraoral scan-bodies; LFP, left first premolar; LLI, left lateral incisor; RLI, right lateral incisor; RFP, right first premolar; DIOS, digital intraoral scanning; DPG, digital photogrammetry.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline \multicolumn{4}{c}{**RMS 3D ISBs Deviation for Precision (Mean \(\pm\) SD)**} \\ \hline ISBs & DIOS (\(n\) = 15) & DPG (\(n\) = 15) & \(p\) Value \\ \hline LFP & 0.042 \(\pm\) 0.020 a & 0.019 \(\pm\) 0.015 a & \textless{}0.001 \\ LLI & 0.042 \(\pm\) 0.016 a & 0.020 \(\pm\) 0.021 a & \textless{}0.001 \\ RLI & 0.032 \(\pm\) 0.007 a & 0.009 \(\pm\) 0.007 a & \textless{}0.001 \\ RFP & 0.043 \(\pm\) 0.012 b & 0.010 \(\pm\) 0.014 a & \textless{}0.001 \\ Global & 0.039 \(\pm\) 0.009 b & 0.014 \(\pm\) 0.013 a & \textless{}0.001 \\ \(p\) value & 0.615 & 0.666 & \\ \hline \hline \end{tabular}  
a,b different letters indicate the presence of significant difference between impression techniques using post hoc tests. RMS, root mean square; ISBs, intraoral scan-bodies; LFP, left first premolar; LLI, left lateral incisor; RLI, right lateral incisor; RFP, right first premolar; DIOS, digital intraoral scanning; DPG, digital photogrammetry.  
\end{table}
Table 2: Means and standards deviations of RMS 3D distortions among implant level impression techniques in terms of precision.  
Figure 7: Mean values of angular deviations among impression techniques when evaluating precision. ISBs, intraoral scan-bodies; LFP, left first premolar; LLI, left lateral incisor; RLI, right lateral incisor; RFP, right first premolar; DIOS, digital intraoral scanning; DPG, digital photogrammetry.  
For trueness, means and standard deviations for angular discrepancy were significantly different between impression techniques (\(p<0.001\)); it was the lowest with DPG (0.724 \(\pm\) 0.064\({}^{\circ}\)) and elevated for DIOS (1.744 \(\pm\) 0.175\({}^{\circ}\)). With DIOS and DPG, the angular deviations within the ISBs were also significantly different. For DIOS, deviation was the highest on LLI and RFP, intermediary on LFP, and the smallest on RLI (\(p<0.001\)) but no significant differences were found between LLI and RFP (\(p=1.000\)). With DPG, it was smaller on LLI, intermediate on LFP followed by RFP and elevated on RLI (\(p<0.001\)). The mean RMS 3D deviation was significantly different between impression techniques (\(p<0.001\)); it was smaller with DPG (0.078 \(\pm\) 0.001) and raised with DIOS (0.536 \(\pm\) 0.063). The mean RMS 3D deviation within the ISBs was also significantly different (\(p<0.001\)). With DIOS, it was elevated on LLI and RLI, intermediate on RFP, and smaller on LFP (\(p<0.001\)). The difference was not significant between RLI and LLI (\(p=1.000\)). With DPG, the 3D deviation was smaller on LLI, followed by RFP, RLI and finally elevated on LFP (\(p<0.001\)).  
For precision, the mean angular deviation was not significantly different between impression techniques (\(p=0.067\)) and within ISBs for DIOS (\(p=0.090\)), and DPG (\(p=0.725\)). The mean RMS was significantly different between impression techniques (\(p<0.001\)); it was smaller with DPG (0.014 \(\pm\) 0.013) and elevated with DIOS (0.039 \(\pm\) 0.009) The mean RMS for 3D deviation within ISBs was not significantly different for DIOS (\(p=0.615\)) and DPG (\(p=0.666\)).