To compare the divergence between the preoperatively designed and the clinically achieved positions of a single posterior implant with the same length, employing two commonly utilized static implant planning software applications within a tooth-supported, partially guided surgical framework. A total of 75 implant placement instances were reviewed in this retrospective analysis. The preoperative design was performed using the GuideMia Implant System in 40 cases and the 3Shape Implant Studio in 35 cases. The actual implant location captured on postoperative cone-beam computed tomography was fused with the virtual treatment plan. For both cohorts, coronal, apical, and angular discrepancies in the 3D spatial orientation were quantified via an auxiliary evaluation software tool. Six variables with the potential to affect precision were individually assessed: the arch, the placement site, the implant brand, the absence of distal abutment teeth, and the implant dimensions (length and diameter). To trace the origins of the observed discrepancies, linear regression models were developed. The comparison of the two implant planning software solutions revealed no statistically significant difference, regardless of implant length (8, 10, or 12 mm, P > 0.05). Conversely, notable differences were recorded for the entry point (P = 0.003), the apical termination(P = 0.005), and the angular orientation (P = 0.002) when contrasting free-end scenarios with bounded saddle scenarios. The planning software applications demonstrated comparable precision in implant placement for identical implant lengths. Nonetheless, the positioning of an implant at the distal extension of a posterior single-tooth edentulous space significantly influences overall accuracy.
