At all three loading sites, no. 36 had the greatest displacement; the more mesial the implant, the less the displacement, and the distal portions showed a sinking displacement (Figure 10). Central loading resulted in the least displacement; buccal and lingual loading showed substantially similar displacements. Compared with the contact model, the fixation model demonstrated less displacement, but aspects of the displacements showed similar tendencies. The results of the ANOVA showed that significant factors for the three-dimensional displacement were assessment site, dental formula, and loading point in both the contact and fixation models (p < 0.05) (Table 5).

Figure 11 shows the equivalent stress distribution for each loading point in the first molar implant section under 100 N of vertical loading. The concentrated site of equivalent stress generated in the artificial mandibular bone in the contact and fixation models was on the buccal side of the bone surrounding the implant neck during buccal loading, the lingual side during lingual loading, and the distal center during central loading. This means that a stress concentration was observed in the bone surrounding the implant neck on the loading side. A minute amount of stress generation was observed at the implant tip and threads as well. The contact model had a larger stress concentration range than the fixation model.

Figure 12, Table 6, and Table 7 show the results for the equivalent stress values of the implants at each loading point under 100 N of vertical loading.

The equivalent stress values of the fixation model were lower at all loading sites than the contact model (Figure 12a). The value was smallest under central loading; buccal loading and lingual loading showed equivalent values. For more distal implants, greater stress values were exhibited. The results of the ANOVA showed that in bone surrounding the implant neck, significant factors for the equivalent stress value were boundary conditions, dental formula, and loading point (p < 0.01) (Table 6). The maximum CV was 16.75% in the contact model and 7.03% in the fixation model (Table 7).