Sources of Error in Static Computer-Assisted Implant Surgery: A Critical Review of Error Propagation Through the Digital Workflow

Static computer-assisted implant surgery (sCAIS) relies on a chain of digital, manufacturing, and clinical steps to transfer the virtually planned implant position to the patient. Although static surgical guides improve implant placement accuracy compared with freehand techniques, clinically relevant deviations persist, and existing systematic reviews mainly report the final planned-versus-placed discrepancy, while evidence on individual workflow stages remains dispersed across several disciplines. This critical review synthesizes quantitative evidence on stage-specific sources of dimensional and angular inaccuracy across the complete workflow, including cone-beam computed tomography (CBCT) and intraoral data acquisition, image registration and segmentation, virtual implant planning, guide design, additive manufacturing, washing, post-curing, sleeve installation, sterilization, guide seating, and drilling. Reported stage-specific discrepancies are generally in the submillimeter range, commonly from several hundredths to several tenths of a millimeter, whereas final clinical deviations are larger, with pooled mean deviations of approximately 1.2 mm at the implant entry point, 1.4 mm at the apex, and 3.5° in angulation reported in a consensus meta-analysis. Because these values describe different quantities and differ in magnitude and direction, they cannot be compared directly or summed; their relationship to the final deviation is therefore presented as a conceptual framework rather than a quantitative model. Printer accuracy alone does not determine the accuracy of guided implant surgery. Validated printer–resin and post-processing protocols, appropriate guide design, verification checkpoints at stage transitions, and reliable clinical seating and stabilization are recommended to limit error transfer. Further research is particularly needed to quantify the isolated contributions of washing, post-curing, sleeve installation, guide movement, and operator-related intraoperative factors.