Premium
Stress Distribution after Installation of Fixed Frameworks with Marginal Gaps over Angled and Parallel Implants: A Photoelastic Analysis
Author(s) -
Markarian Roberto Adrian,
Ueda Cristiane,
Sendyk Claudio Luiz,
Laganá Dalva Cruz,
Souza Roberto Martins
Publication year - 2007
Publication title -
journal of prosthodontics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.902
H-Index - 60
eISSN - 1532-849X
pISSN - 1059-941X
DOI - 10.1111/j.1532-849x.2007.00161.x
Subject(s) - photoelasticity , implant , materials science , stress (linguistics) , structural engineering , orthodontics , composite material , engineering , solid mechanics , surgery , medicine , linguistics , philosophy
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° 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 μm 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.