OBJECTIVE: To compare implant accuracy of combined static and dynamic (SD) computer-assisted implant surgery (CAIS) with static (S), dynamic (D) CAIS, and freehand surgery (FH) for single implant placement. MATERIALS AND METHODS: One hundred and twenty patients were randomized into four groups. Implants were placed using both stereolithographic surgical guide and dynamic navigation in the SD group, stereolithographic surgical guide in S group, dynamic navigation in D group, and conventional freehand in FH group. Analysis of deviation between planned and final implant position, as well as K means analysis was conducted for implant deviation at platform, apex, and angle (primary outcomes) and directional distribution at platform and apex (secondary outcome). RESULTS: Significant differences were found among the four groups (p < .001): The 3D deviation at the platform (mm) of SD, S, D, and FH groups was 0.62 ± 0.50, 1.06 ± 0.67, 1.02 ± 0.45, and 1.48 ± 0.68, respectively, at apex (mm) was 0.75 ± 0.57, 1.40 ± 0.71, 1.28 ± 0.50, and 2.18 ± 0.95, respectively, and angle (degrees) was 1.24 ± 1.41, 3.18 ± 2.04, 3.28 ± 1.57, and 7.50 ± 4.06, respectively. Deviation at the platform of FH group was significantly more toward mesial (p = .026) and coronal (p = .014) direction, while at the apex, toward distal (p = .004) and lingual (p = .002) than SD group. CONCLUSION: The use of combined static and dynamic CAIS provided significantly higher accuracy than the two alone and freehand surgery for single implant placement.