The All-on-Four Treatment Concept: A Narrative Review
DOI:
https://doi.org/10.55995/bdwsqz38Keywords:
All-On-Four, Tilted implants, Dental implants, Immediate loading, Atrophic maxilla and mandibleAbstract
Edentulism continues to pose a major rehabilitative challenge, particularly in patients with severely atrophic jaws where conventional implant placement is often precluded by insufficient bone volume. The All-On-Four treatment concept has emerged as a graftless alternative, using four strategically positioned implants; two placed axially in the anterior region and two tilted up to 45° posteriorly to support an immediate, fullarch fixed prosthesis while maximizing use of available native bone. This narrative review synthesizes current literature on the concept's evolution, surgical and prosthetic protocols, biomechanical principles, and long-term clinical performance, drawn from a structured search of PubMed/MEDLINE and the Cochrane Library. Since its formal introduction in the early 2000s, the protocol has been refined through variations such as the Hybrid and Quad-Zygoma approaches for cases with more extreme bone deficiency. Reported implant survival consistently exceeds 93% across follow-up periods extending beyond a decade, with marginal bone loss generally remaining within accepted biological limits. Mechanical complications, particularly denture-tooth fracture and screw loosening, are more common than biological ones, and their incidence is closely tied to cantilever length and prosthetic framework material. Patientreported outcomes also favor the approach, showing marked gains in masticatory function and quality of life relative to conventional dentures. Despite this favorable evidence base, most supporting data derive from retrospective, single-center cohorts, underscoring the need for prospective, multicenter trials with extended follow-up. Overall, when guided by careful patient selection and prosthodontically driven planning, the All-On-Four concept offers a predictable, cost-effective solution for full-arch rehabilitation of the severely compromised edentulous arch.
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