Stackable Surgical Guides in Full-Arch Implant Rehabilitation: What They Can Deliver and Where the Evidence Still Constrains Use — A Critical Narrative Review

Objectives: This review examines the current role of stackable surgical guides in full-arch implant rehabilitation, with particular attention to what these systems can reliably achieve in clinical practice and where the available evidence remains insufficient to support broader claims. Materials and methods: A critical narrative review of PubMed/MEDLINE and Scopus was conducted and updated through August 2026. The search combined the terms “stackable,” “sequential,” and “modular” surgical guides with “dental implant,” “full arch,” “bone reduction,” “accuracy,” and “immediate loading.” Clinical studies, evidence syntheses, and relevant laboratory investigations were assessed individually. Because of the heterogeneity of the available literature and the narrative design of the review, no meta-analysis or formal risk-of-bias assessment was performed. Results: Stackable systems use a stable base with interchangeable components to maintain the planned reference throughout bone management, implant placement, and prosthetic transfer. The available clinical evidence remains limited. A 2024 scoping review identified only 12 case reports or case series, including 25 patients, 27 arches, and 173 implants, and accuracy was quantified in only four of these reports. More recent clinical studies provide additional information, although their findings remain specific to the protocols investigated. In one retrospective series involving 60 implants placed with a rigid, bone-fixed base, mean angular, neck, and apical deviations were 1.25°, 0.96 mm, and 1.07 mm, respectively. The first in vivo comparison with other forms of static guide support found no overall accuracy advantage for stackable guides and reported the greatest vertical discrepancy in the stackable group (0.26 mm; P<.001). In the 43-arch STAGE cohort, approximately 93% of arches were loaded on the day of surgery, while 274 of 284 implants had osseointegrated at four months. Implant replacements and provisional fractures were nevertheless reported. Conclusions: Current evidence supports stackable guides primarily as a method for maintaining a common planned reference throughout successive surgical and restorative steps. In appropriately selected cases, they can facilitate prosthetically driven implant placement, guided or selective bone reduction, and immediate provisionalization. Available studies, however, do not establish superiority over conventional guidance, identify one stackable design as preferable to another, provide validated criteria for bone reduction, or demonstrate advantages in patient-reported outcomes or cost-effectiveness