Accurate implant positioning remains the goal of guided surgery for improving surgical outcomes and minimizing complications. The aim is to compare the accuracy of standard versus novel drilling key in static-dynamic computer assisted implant surgery across D2 and D3 bone densities relative to a zero-deviation benchmark.

Sixty-four bone-level tapered implants were placed in 32 models across four groups (n = 16), stratified by drilling key designs (standard vs novel) and bone density (D2 vs D3). Preoperative cone-beam computed tomography (CBCT) was imported into the navigation system for implant planning. Surgical guide was designed to match the navigation planning. Implant placement followed the manufacturer protocols. Postoperative CBCT was superimposed on pre-operative plan to measure 3D platform, 3D apex, and angular deviations. Two-way ANOVA, Levene, Kruskal–Wallis, and post-hoc Mann–Whitney U tests were used ( p < 0.05).

The novel drilling key significantly reduced angular deviation compared to the standard key (1.84°± 1.58 vs 0.21°± 0.56, p < 0.001); 3D platform (0.78 ± 0.30 vs 0.74 ± 0.17 mm, p = 0.262) and apex (0.82 ± 0.31 vs 0.93 ± 0.41 mm , p = 0.596) were comparable. D3 bone showed higher 3D apex ( p = 0.017) and angular deviations ( p = 0.044) than D2.

The findings imply that the novel key design provides a targeted advantage in reducing angular deviation in both bone densities while linear deviations at the platform and apex remain influenced by bone density and other potential sources of error within the guided workflow.

This study addresses accuracy in implant dentistry in technically challenging cases such as long free drilling distance where low sleeve positioning is not feasible.