Accuracy of Flapless Immediate Implant Placement in Anterior Maxilla Using Computer-assisted Versus Freehand Surgery: A Cadaver Study
Z Chen, J Li, K Sinjab, G Mendonca, H-L Wang
Objective: To compare the accuracy of computer-guided surgery and freehand surgery on flapless immediate implant placement in the anterior maxilla.Material and Methods: In this split mouth design, 24 maxillary incisors in 8 human cadaver heads were randomly divided into 2 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 an implant planning software (Blue Sky Plan3, Blue Sky Bio, Grayslake, IL). Then, two types of surgeries were performed. To assess any differences in position, the preoperative CBCT was subsequently matched with the postoperative one. For all the implants, the angular, global, depth, and lateral deviations between the virtually planned and the achieved implant positions were measured. The lateral deviation was further subdivided into bucco-lingual and mesio-distal deviations. Results: A significant lower mean angular deviation (3.11±1.55°, range: 0.66–4.95), as well as the global deviation at both coronal (0.85±0.38 mm, range: 0.42–1.51) and apical level (0.93±0.34 mm, range: 0.64–1.72) were observed in the guided group when compared to the freehand group (6.78±3.31°, range: 3.08–14.98; 1.42±0.49 mm, range: 0.65–2.31 and 2.2±0.79mm, range: 1.01–4.02). However, the accuracy of these 2 approaches was similar for the depth parameter (P=0.847). In the bucco-lingual direction, the mean deviations of these two groups showed a general tendency of implants to be positioned facially, occurring more in implants of the freehand group. Conclusion: In flapless immediate implant placement, computer-guided surgery showed superior accuracy than freehand surgery in transferring the virtual implant position to the actual bone site. However, even with the help of a guide, the final fixture position has a tendency to shift towards a facial direction.