In AOX (All-on-X) full-arch restorations, cantilever length is one of the most critical biomechanical factors affecting long-term success.
Excessive distal cantilever increases bending forces on terminal implants and may lead to:
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Screw loosening
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Prosthetic fracture
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Framework distortion
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Crestal bone stress
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Implant overload
📐 Biomechanical Considerations
Cantilever force increases exponentially with length. Even a small extension beyond the last implant can significantly amplify stress during function.
General clinical guidelines suggest:
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Keep cantilever length within a safe A-P spread ratio
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Avoid extending beyond biomechanical limits of the arch
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Evaluate opposing occlusion and parafunctional risk
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Minimize distal contacts in excursive movements
Each case should be evaluated individually based on bone quality, implant distribution, and occlusal scheme.
