Related Experiment Video
Updated: Aug 5, 2026
14:31
Bioelectric Analyses of an Osseointegrated Intelligent Implant Design System for Amputees
Published on: July 15, 2009
Evaluation of Stress Distribution in "All-on-Four" Prostheses: A Three-Dimensional Finite Element Analysis
Eduardo Francisco de Souza Faco1, Andressa Paschoal Amoroso2, Flávia Priscila Pereira3
1Department of Diagnosis and Surgery, School of Dentistry, São Paulo State University (UNESP), Araçatuba 16010-380, SP, Brazil.
Life (Basel, Switzerland)
|July 28, 2026
Summary
The All-on-Four implant configuration, with tilted distal implants, results in higher stress concentrations compared to straight implants. This biomechanical analysis highlights potential risks associated with tilted implant designs in full-arch prostheses.
Area of Science:
- Biomaterials Engineering
- Dental Implantology
- Biomechanics
Background:
- Increasing demand for implant-supported prostheses necessitates biomechanical optimization for force distribution.
- Understanding stress distribution is crucial for the long-term success of full-arch rehabilitations.
Purpose of the Study:
- To evaluate stress distribution in full-arch implant-supported prostheses with varying implant angulations.
- To compare biomechanical performance between straight and tilted (All-on-Four) distal implant configurations.
Main Methods:
- Three-dimensional finite element analysis (FEA) of two mandibular models.
- Models featured external hex implants, one with perpendicular implants, the other with 30° tilted distal implants (All-on-Four).
- Simulated axial and oblique loading on premolars and molars.
Main Results:
- The tilted-implant (All-on-Four) model demonstrated significantly higher stress concentrations under both axial and oblique loading.
- Elevated stress levels were most pronounced around the distal implants in the All-on-Four configuration.
Conclusions:
- The All-on-Four concept with tilted distal implants leads to increased stress distribution compared to straight implants.
- Findings suggest potential biomechanical disadvantages for the All-on-Four configuration regarding stress concentration.
Related Concept Videos
01:04Applications of Stress
Consider a structure made of a boom and a rod designed to support a load. These two components are connected by a pin and stabilized by brackets and pins. The boom and the rod are detached from their supports to assess the different stresses imposed on this structure, and a free-body diagram is drawn. Then, all the forces applied, including the load acting on the structure, are identified. The reaction forces exerted on both the boom and the rod are computed using the equilibrium equations.
The...
The...
01:15Stress: General Loading Conditions
To grasp the intricacy of real-world conditions where multiple loads are applied simultaneously to a structure, one might visualize a section passing through a specific point within a body, aligned parallel to the xy plane. This section is subjected to various forces, including original loads, normal forces, and shearing forces.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
The shearing force, possessing potential directionality within the plane of the section, is simplified into two component forces running parallel to the x and y axes.
01:23Components of Stress
Stress analysis under multiple loading conditions is intricate, necessitating a comprehensive grasp of normal and shearing stresses. Consider a small cube at point O, subjected to stress on all six faces, visible or not. Normal stress components σx, σy, σz act perpendicularly to the x, y, and z axes. Shearing stress components τxy and τxz are exerted on faces perpendicular to these axes.
Interestingly, the hidden cube faces also experience these stresses, equal and opposite to those on the...
Interestingly, the hidden cube faces also experience these stresses, equal and opposite to those on the...
01:18Transformation of Plane Stress
Studying stress transformation is essential in understanding how stress components within a material, like a cube under plane stress, change with rotation. This change is analyzed by considering a prismatic element within the cube. As the element rotates, the stress components acting on it—both normal and shearing stresses—change in magnitude and orientation. This change is quantified using trigonometric functions of the rotation angle, relating the forces acting on the rotated element's faces...
01:18Stress Concentrations in Circular Shafts
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
01:23Stresses under Combined Loadings
When analyzing a bent tube with a circular cross-section subjected to multiple forces, it is crucial to determine the stress distribution in order to maintain structural integrity under varied load conditions.
The process begins by slicing the tube at critical points and analyzing the internal forces and stress components at these sections, focusing on the centroid. Normal stresses, generated by axial forces and bending moments, are either compressive or tensile and vary across the section from...
The process begins by slicing the tube at critical points and analyzing the internal forces and stress components at these sections, focusing on the centroid. Normal stresses, generated by axial forces and bending moments, are either compressive or tensile and vary across the section from...