## 3 Results  
Three-way ANOVA revealed significant main effects on trueness of implant level (\(F\) = 515.319, \(p\) \(<\) 0.001), scanner (\(F\) = 29.620, \(p\) \(<\) 0.001), and tooth position (\(F\) = 65.780, \(p\) \(<\) 0.001); significant two-way interaction effects between scanner and implant level (\(F\) = 13.122, \(p\) \(<\) 0.001), tooth position and implant level (7.875, \(p\) \(<\) 0.001), and scanner and tooth position (\(F\) = 2.237, \(p\) \(<\) 0.039); and a significant three-way interaction effect between scanner, tooth position, and implant level (\(F\) = 2.710, \(p\) \(<\) 0.001). In order to identify the accuracy in reproducing the implant position according to changes in the exposed length of the ISB, scanner type, and tooth position, three-way ANOVA was performed to compare the average standard deviations of the RMS values (Figure 6). The RMS values for trueness did not differ significantly between implant depths of normal bone level, submerged 1.5 mm, and submerged 3.0 mm (23.0 \(\pm\) 12.4 \(\upmu\)m, 24.3 \(\pm\) 14.2 \(\upmu\)m, and 27.2 \(\pm\) 15.6 \(\upmu\)m, respectively). However, when the ISB was submerged 4.5 mm, corresponding to deeper implant placement, the deviation increased significantly to 42.8 \(\pm\) 25.1 \(\upmu\)m, while a submersion of 6.0 mm showed the largest deviation of 102.5 \(\pm\) 29.5 \(\upmu\)m, indicating that the accuracy was degraded. Comparisons of trueness with T500-REF data revealed that the accuracy varied with the type of scanner. The RMS value was 36.9 \(\pm\) 33.7 \(\upmu\)m for the T500 scanner, 50.8 \(\pm\) 38.2 \(\upmu\)m for the i500 scanner, and did not differ significantly between the TRIOS 3 (44.4 \(\pm\) 41.7 \(\upmu\)m) and CS3600 (46.5 \(\pm\) 32.1 \(\upmu\)m) scanners. The RMS value did not differ significantly between the first premolar (36.9 \(\pm\) 33.8 \(\upmu\)m) and the first molar (42.5 \(\pm\) 36.8 \(\upmu\)m), but was significantly higher for the implant placed on the lateral incisor (55.9 \(\pm\) 37.9 \(\upmu\)m), indicating lower accuracy. One-way ANOVA was performed to evaluate the trueness according to changes in the exposed length of the ISB, scanner type, and tooth position (Table S1, Figure 7). The RMS value tended to be low in all of the implanted groups when the implant was installed at the normal bone level. The T500 scanner showed the lowest variance in all groups, and the highest trueness. For this scanner, when the implant was submerged 6.0 mm at the positions of the lateral incisor, first premolar, and first molar, the RMS values increased significantly to 108.0 \(\pm\) 26.1 \(\upmu\)m, 74.4 \(\pm\) 17.0 \(\upmu\)m, and 75.5 \(\pm\) 30.9 \(\upmu\)m, respectively, indicating decreased trueness. In the case of the TRIOS 3 scanner, when the implant was submerged 4.5 mm at the positions of the lateral incisor and first molar, the RMS values increased significantly to 53.4 \(\pm\) 6.9 \(\upmu\)m and 35.9 \(\pm\) 17.5 \(\upmu\)m, respectively. For a submersion of 6.0 mm, the RMS values at the lateral incisor, first premolar, and first molar increased rapidly to 125.8 \(\pm\) 5.4 \(\upmu\)m, 117.2 \(\pm\) 6.8 \(\upmu\)m, and 125.6 \(\pm\) 2.9 \(\upmu\)m, respectively, indicating decreased trueness. In the case of the i500 scanner, the RMS value increased significantly to 43.1 \(\pm\) 12.0 \(\upmu\)m when the implant was submerged 3.0 mm at the position  
Figure 6: Trueness according to implant placement depth (**A**), scanner (**B**), and tooth position (**C**). Different lowercase letters indicate significant differences within each group. Data are mean and standard deviation values. of the lateral incisor. At the positions of the first premolar and first molar, when the ISB was submerged 4.5 mm, the RMS values were significantly higher at 71.3 \(\pm\) 8.3 \(\upmu\)m and 57.8 \(\pm\) 10.1 \(\upmu\)m, respectively.