Accuracy of flapless immediate implant placement in anterior maxilla using computer-assisted versus freehand surgery: A cadaver study

Objective: To compare the accuracy of computer-guided surgery and freehand surgery on flapless immediate implant placement (IIP) in the anterior maxilla.

Material and methods: In this split-mouth design, 24 maxillary incisors in eight human cadaver heads were randomly divided into two groups: computer-guided surgery (n = 12) and freehand surgery (n = 12). Preoperatively, cone-beam computed tomography (CBCT) scans were acquired, and all implants were planned with a software (Blue Sky Plan3). Then, two types of surgeries were performed. To assess any differences in position, the postoperative CBCT was subsequently matched with the preoperative planning. For all the implants, the angular, global, depth, bucco-lingual, and mesio-distal deviations between the virtual and actual implant positions were measured.

Results: A significant lower mean angular deviation (3.11 ± 1.55°, range: 0.66-4.95, p = 0.002) and the global deviation at both coronal (0.85 ± 0.38 mm, range: 0.42-1.51, p = 0.004) and apical levels (0.93 ± 0.34 mm, range: 0.64-1.72, p < 0.001) were observed in the guided group when compared to the freehand group (6.78 ± 3.31°, range: 3.08-14.98; 1.43 ± 0.49 mm, range: 0.65-2.31, and 2.2 ± 0.79 mm, range: 1.01-4.02). However, the accuracy of these two approaches was similar for the depth (p = 0.366). In the buccal direction, the mean deviations of both groups showed a general tendency of implants to be positioned facially, occurring more in implants of the freehand group.

Conclusion: In flapless IIP, computer-guided surgery showed superior accuracy than freehand surgery in transferring the implant position from the planning. However, even with the help of a guide, the final fixture position tends to shift toward a facial direction.