Surgical Efficiency, Learning Dynamics, and Positional Accuracy of Freehand Immediate Implant Placement Under...

To characterize surgical efficiency and within-operator learning dynamics during freehand immediate post-extraction implant placement performed under standardized, prosthetically driven digital planning, and to describe the positional accuracy achieved across operators of differing experience in a 3D-printed phantom model.

In a prospective in vitro study, 80 tissue-level implants (TLC/TLX; Institut Straumann AG) were placed by three operators stratified by cumulative experience (0; <30; >100 implants) at ten anterior maxillary sites on standardized 3D-printed extraction-socket phantoms. All sites were planned in coDiagnostix and prepared with an identical drill sequence; implant type was disclosed only after osteotomy completion. Site and implant allocation were randomized using permuted blocks, and a blinded examiner performed all digital superimposition. The primary outcome was angular deviation; secondary outcomes were 3D offset at the implant base and apex and total procedure time. Between-operator comparisons used the Kruskal-Wallis test and Bonferroni-corrected Mann-Whitney U tests; within-operator learning was evaluated by regression of outcomes against sequential case order.

Seventy-six implants were evaluable. Positional accuracy did not differ between operators for any metric after correction (angular deviation: Novice 7.14°, Intermediate 9.36°, Expert 7.11°; Kruskal-Wallis P = 0.086; 3D offset at base P = 0.154; at apex P = 0.710), and all values fell within published freehand benchmark ranges. Total procedure time differed across operators (Expert 3.71 ± 1.49, Intermediate 4.96 ± 1.50, Novice 6.40 ± 2.83 minutes; P < 0.001), and all three operators showed a significant reduction in procedure time across sequential cases (P = 0.036, P < 0.001, and P = 0.008). Procedure time was not associated with any accuracy metric (Spearman ρ = -0.114 to 0.005; all P > 0.30). Overall, TLC and TLX did not differ in positional accuracy (all P ≥ 0.340).

Under standardized prosthetically driven planning, positional accuracy did not differ significantly across operators and fell within established freehand benchmark ranges, whereas procedure time and within-operator efficiency gains were the principal differentiators. Because each experience level comprised a single operator, comparisons are operator-level and do not support experience-based generalization.