title: Photoelastic Analysis on Different Retention Methods of Implant-Supported Prosthesis.
abstract: The aim of this study was to evaluate the stress distribution of different retention systems (screwed, cemented, and mixed) in 5-unit implant-supported fixed partial dentures through the photoelasticity method. Twenty standardized titanium suprastructures were manufactured, of which 5 were screw retained, 5 were cement retained, and 10 were mixed (with an alternating sequence of abutments), each supported by 5 external hexagon (4.0 mm × 11.5 mm) implants. A circular polariscope was used, and an axial compressive load of 100 N was applied on a universal testing machine. The results were photographed and qualitatively analyzed. We observed the formation of isochromatic fringes as a result of the stresses generated around the implant after installation of the different suprastructures and after the application of a compressive axial load of 100 N. We conclude that a lack of passive adaptation was observed in all suprastructures with the formation of low-magnitude stress in some implants. When cemented and mixed suprastructures were subjected to a compressive load, they displayed lower levels of stress distribution and lower intensity fringes compared to the screwed prosthesis.
authors.affiliation: 1  Department of Implantology at the University of Santo Amaro, São Paulo, Brazil.
authors.forename: Angélica Castro
authors.initials: AC
authors.lastname: Pimentel
authors.affiliation: 2  School of Dentistry, Department of Oral and Maxillofacial Surgery and Traumatology, University of São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Marcello Roberto
authors.initials: MR
authors.lastname: Manzi
authors.affiliation: 2  School of Dentistry, Department of Oral and Maxillofacial Surgery and Traumatology, University of São Paulo (USP), São Paulo, SP, Brazil.
authors.forename: Cristiane Ibanhês
authors.initials: CI
authors.lastname: Polo
authors.affiliation: 3  Prosthodontics, University of São Paulo (USP), São Paulo, Brazil.
authors.forename: Claudio Luiz
authors.initials: CL
authors.lastname: Sendyk
authors.affiliation: 4  University of São Paulo (USP), São Paulo, Brazil.
authors.forename: Maria
authors.initials: M
authors.lastname: da Graça Naclério-Homem
authors.affiliation: State University of Campinas (UNICAMP); Graduate Program in Implant Dentistry at the University of Santo Amaro (UNISA), São Paulo, Brazil.
authors.forename: Wilson Roberto
authors.initials: WR
authors.lastname: Sendyk
mesh_terms: D001696:Biomechanical Phenomena; D003738:Dental Cements; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003830:Denture, Partial, Fixed; D013314:Stress, Mechanical
chemical_list: D003738:Dental Cements; D015921:Dental Implants
keywords: dental implants; prosthesis; stress; suprastructure