title: Stress distribution in Co-Cr implant frameworks after laser or TIG welding.
abstract: Lack of passivity has been associated with biomechanical problems in implant-supported prosthesis. The aim of this study was to evaluate the passivity of three techniques to fabricate an implant framework from a Co-Cr alloy by photoelasticity. The model was obtained from a steel die simulating an edentulous mandible with 4 external hexagon analog implants with a standard platform. On this model, five frameworks were fabricated for each group: a monoblock framework (control), laser and TIG welding frameworks. The photoelastic model was made from a flexible epoxy resin. On the photoelastic analysis, the frameworks were bolted onto the model for the verification of maximum shear stress at 34 selected points around the implants and 5 points in the middle of the model. The stresses were compared all over the photoelastic model, between the right, left, and center regions and between the cervical and apical regions. The values were subjected to two-way ANOVA, and Tukey's test (α=0.05). There was no significant difference among the groups and studied areas (p>0.05). It was concluded that the stresses generated around the implants were similar for all techniques.
authors.affiliation: Department of Prosthodontics and Periodontics, Piracicaba Dental School, UNICAMP - University of Campinas, Piracicaba, SP, Brazil. cassarodecastro@gmail.com
authors.forename: Gabriela Cassaro
authors.initials: GC
authors.lastname: de Castro
authors.forename: Cleudmar Amaral
authors.initials: CA
authors.lastname: de Araújo
authors.forename: Marcelo Ferraz
authors.initials: MF
authors.lastname: Mesquita
authors.forename: Rafael Leonardo Xediek
authors.initials: RL
authors.lastname: Consani
authors.forename: Mauro Antônio de Arruda
authors.initials: MA
authors.lastname: Nóbilo
mesh_terms: D002858:Chromium Alloys / Q000737:chemistry*; D003735:Dental Casting Technique; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D012994:Dental Soldering / Q000295:instrumentation / Q000379:methods*; D004853:Epoxy Resins / Q000737:chemistry; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D007834:Lasers; D008334:Mandible / Q000473:pathology; D008422:Materials Testing; D003765:Models, Dental; D058626:Plasma Gases; D013314:Stress, Mechanical; D013499:Surface Properties; D014896:Welding / Q000295:instrumentation / Q000379:methods
chemical_list: D002858:Chromium Alloys; D015921:Dental Implants; D004853:Epoxy Resins; D058626:Plasma Gases