title: Photoelastic stress analysis of mandibular fixed prostheses supported by 3 dental implants.
abstract: OBJECTIVE
  To observe the photoelastic stress patterns generated around implants in relation to variations in the diameter and total number of implants supporting fixed complete-arch mandibular frameworks.
  
  
  METHODS
  Three different implant configurations were analyzed (n = 3): 5 standard implants with diameters of 3.75 mm (C), 3 standard implants with diameters of 3.75 mm (3S), and 3 wide implants with diameters of 5.0 mm (3W). The samples were subjected to a vertical compressive load (1.33 kgf) applied at the end of the distal cantilever of the framework. The shear stresses were calculated around the implants, and the data were analyzed using one-way analysis of variance.
  
  
  RESULTS
  The implants nearest to the loading showed higher stress values regardless of the group. The C group showed lower shear stress when compared with the other groups (P = 0.001). No significant difference was observed between the 3W and 3S groups (P = 0.785).
  
  
  CONCLUSIONS
  A reduction in the number of implants, regardless of the implant diameter, showed higher stress concentration around the implants. Five-implant configuration showed lower stress concentration and seems to be more biomechanically predictable.
authors.affiliation: *Adjunct Professor, Department of Occlusion, Fixed Prostheses, and Dental materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Brazil. †Professor, Department of Prosthodontics, School of Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil. ‡Adjunct Professor, Department of Operative Dentistry and Dental materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Brazil. §Titular Professor, Piracicaba Dental School, Department of Prosthodontics and Periodontics, University of Campinas, Piracicaba, Brazil. ‖Associate Professor, Department of Occlusion, Fixed Prostheses, and Dental materials, School of Dentistry, Federal University of Uberlândia, Uberlândia, Brazil. ¶Professor, Mechanical Projects Laboratory, Mechanical Engineering School, Federal University of Uberlândia, Uberlândia, Brazil.
authors.forename: Paulo Cézar
authors.initials: PC
authors.lastname: Simamoto Júnior
authors.forename: João Paulo
authors.initials: JP
authors.lastname: da Silva-Neto
authors.forename: Veridiana Resende
authors.initials: VR
authors.lastname: Novais
authors.forename: Mauro Antônio
authors.initials: MA
authors.lastname: de Arruda Nóbilo
authors.forename: Flávio Domingues
authors.initials: FD
authors.lastname: das Neves
authors.forename: Cleudmar Amaral
authors.initials: CA
authors.lastname: Araujo
mesh_terms: D001696:Biomechanical Phenomena; D019245:Compressive Strength; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis / Q000379:methods*; D004548:Elasticity; D006801:Humans; D066298:In Vitro Techniques; D008334:Mandible; D014025:Titanium; D019415:Torque
chemical_list: D014025:Titanium