Objective A buccal opening guide provides better view and better irrigation. The aim of this study was to investigate the accuracy of this open-sleeve system. Material and Methods Thirty duplicated maxillary models, each with six extraction sockets and four healed sites, were used. Based on the same digital plan, three modalities, sCAIS with open-sleeves, closed-sleeves, and free-hand approach, were used to place implants. The global, horizontal, depth, and angular deviations between the virtual and actual implant positions were measured. Results Both sCAIS groups exhibited better accuracy than the free-hand group in two clinical scenarios. At healed sites, the closed-sleeve group showed a significantly fewer error than the open-sleeve group in global apical (0.68 +/- 0.33 vs. 0.96 +/- 0.49 mm), horizontal coronal (0.28 +/- 0.15 vs. 0.44 +/- 0.25 mm), horizontal apical (0.64 +/- 0.32 vs. 0.94 +/- 0.48 mm), and angular deviations (1.83 +/- 0.95 vs. 2.86 +/- 1.46 degrees). For extraction sockets, the open-sleeve group exhibited fewer deviations than the closed-sleeve group in terms of global (coronal: 0.77 +/- 0.29 vs. 0.91 +/- 0.22 mm; apical: 1.08 +/- 0.49 vs. 1.37 +/- 0.52 mm) and horizontal (coronal: 0.60 +/- 0.24 vs. 0.86 +/- 0.20 mm; apical: 0.95 +/- 0.50 vs. 1.32 +/- 0.51 mm) deviations. However, the closed-sleeve group was more accurate in the depth control (0.26 +/- 0.20 vs. 0.40 +/- 0.31 mm). Conclusion In this in vitro investigation, open-sleeve sCAIS proved better accuracy than free-hand surgery for both delayed and immediate implant placement. Compared with a closed-sleeve sCAIS system, open sleeve have the potential of providing better outcomes in extraction sockets but not in healed sites.
