Related Experiment Video
Updated: Jul 16, 2026

In situ Compressive Loading and Correlative Noninvasive Imaging of the Bone-periodontal Ligament-tooth Fibrous Joint
Published on: March 7, 2014
Stress distribution after installation of fixed frameworks with marginal gaps over angled and parallel implants: a
Roberto Adrian Markarian1, Cristiane Ueda, Claudio Luiz Sendyk
1MSc Program, Department of Prosthodontics, University of São Paulo School of Dentistry, Brazil. rmarkari@terra.com.br
Purpose:
The objective of this work was to compare by photoelastic analysis the stress distribution along a fixed framework placed over angled or parallel implants with different gap values between the framework and one of the implants.
Materials And Methods:
Two photoelastic models were created: (i) with parallel implants; (ii) with a 30 degrees angled central implant. In both cases, three implants were used, and CP titanium frameworks were constructed with commercial components. A plane polariscope was used to observe the photoelastic fringes generated after initial framework assembly, and also when an axial load of 100 N was applied over the central implant. For both models, stress analysis was conducted on well-fitting frameworks and on another with a 150 microm vertical gap between the framework and the central implant.
Results:
The photoelastic analysis indicated that in the model with parallel implants, stress distribution followed the implant axis, and in the model with an angled implant, a higher and nonhomogeneous stress concentration was observed around the apical region of the lateral implants. The placement of an ill-fitting framework resulted in increased preload stress patterns.
Conclusion:
Stresses were generated after screw tightening of the frameworks, increasing when a load was applied and when a vertical gap was present. Angled implants resulted in oblique stress patterns, which were not transferred with homogeneity to the polymeric model.
More Related Videos
Related Concept Videos
Stress Concentrations
Stress Concentrations
The stress concentration...
Stress: General Loading Conditions
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.
Stress Concentrations in Circular Shafts
Stresses under Combined Loadings
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...
Relation between Poisson's ratio, Modulus of Elasticity and Modulus of Rigidity

