Abstract Purpose This study aimed to compare a retentive surgical guide design with a fixation pin design in unilateral mandibular distal extension cases and evaluate their resulting implant deviations. Materials and methods Ten epoxy models with a soft tissue-simulating layer were used, each fitted with two surgical guide designs. The retentive guide featured clasp-like extensions, a 0.07 mm guide-to-tooth offset, and a 2.3 mm thickness. The fixation pin design had a 0.2 mm offset, a 3 mm thickness, and one fixation pin in the distal edentulous region. Eight directional forces were applied through the drill handle. The models were scanned before and after force application. Simulated implants were inserted into 180 scans, resulting in a total of 306 implants. Post-scan data were superimposed onto the initial plan to assess implant and guide deviation. Results The baseline deviation was 0.34 ± 0.19 mm for the retentive design and 0.30 ± 0.14 mm for the fixation pin design ( P = 1.00). Both designs produced simulated implant deviations within the recommended 2 mm safety margin. However, the retentive design showed significantly greater vertical implant deviation compared to the fixation design (0.99 ± 0.76 mm vs. 0.50 ± 0.34 mm, P < 0.001). Conclusion Incorporating retention features into surgical guides reduces simulated implant displacement in unilateral distal extension cases. However, the retentive guide exhibited larger implant deviations than the fixation design and required additional software adjustments, indicating a need for further refinement.
Elnadoury et al. (Thu,) studied this question.