Sleeveless guided implant placement compared to conventional approaches: An in vitro study at healed sites and fresh extraction sockets

Purpose: To investigate the accuracy of a novel sleeveless implant surgical guide by comparing it with a conventional closed-sleeve guide and a freehand approach.
Materials and methods: Custom resin maxillary casts with corticocancellous compartments were used (n = 30). Seven implant sites were present per max-illary cast, corresponding to healed (right first molar and left first premolar, second premolar, and first molar) and extraction sites (right canine and central incisors). The casts were assigned into three groups: freehand (FH), conventional closed-sleeve guide (CG) and sleeveless guide (SG) groups. Each group comprised 10 casts and 70 implant sites (30 extraction sites and 40 healed sites). Digital planning was used to design 3D printed conventional closed-sleeve and sleeve-less surgical templates. The primary study outcome was implant deviation.
Results: At extraction sites, the largest difference between groups occurred in angular deviation, where the SG group (3.80 ± 1.67 degrees) exhibited ~1.6 times smaller deviation relative to the FH group (6.02 ± 3.44 degrees; P = 0.004). The CG group (0.69 ± 0.40 mm) exhibited smaller coronal horizontal deviation compared to the SG group (1.08 ± 0.54 mm; P = 0.005). For healed sites, the largest difference occurred for angular deviation, where the SG group (2.31 ± 1.30 degrees) exhibited 1.9 times smaller deviation relative to the CG group (4.42 ± 1.51 degrees; P < 0.001), and 1.7 times smaller deviation relative to the FH group (3.84 ± 2.14 degrees). Significant differences were found for all parameters except depth and coronal horizontal deviation. For the guided groups, there were fewer significant differences between healed and immediate sites compared to the FH group.
Conclusion: The novel sleeveless surgical guide showed similar accuracy to the conventional closed-sleeve guide.