title: Cortical bone stress distribution in mandibles with different configurations restored with prefabricated bar-prosthesis protocol: a three-dimensional finite-element analysis.
abstract: OBJECTIVE
  To evaluate stress distribution in different horizontal mandibular arch formats restored by protocol-type prostheses using three-dimensional finite element analysis (3D-FEA).
  
  
  METHODS
  A representative model (M) of a completely edentulous mandible restored with a prefabricated bar using four interforaminal implants was created using SolidWorks 2010 software (Inovart, São Paulo, Brazil) and analyzed by Ansys Workbench 10.0 (Swanson Analysis Inc., Houston, PA) to obtain the stress fields. Three mandibular arch sizes were considered for analysis, regular (M), small (MS), and large (ML). Three unilateral posterior loads (L) (150 N) were used: perpendicular to the prefabricated bar (L1); 30° oblique in a buccolingual direction (L2); 30° oblique in a lingual-buccal direction (L3). The maximum and minimum principal stresses (σ(max), σ(min)), the equivalent von Mises (σ(vM)), and the maximum principal strain (σ(max) ) were obtained for type I (M.I) and type II (M.II) cortical bones.
  
  
  RESULTS
  Tensile stress was more evident than compression stress in type I and II bone; however, type II bone showed lower stress values. The L2 condition showed highest values for all parameters (σ(vM), σ(max), σ(min), ɛ(max)). The σ(vM) was highest for the large and small mandibular arches.
  
  
  CONCLUSIONS
  The large arch model had a higher influence on σ(max) values than did the other formats, mainly for type I bone. Vertical and buccolingual loads showed considerable influence on both σ(max) and σ(min) stresses.
authors.affiliation: Department of Dental Materials and Prosthodontics, Aracatuba School of Dentistry, Universidade Estadual Paulista, Araçatuba, SP,Brazil.
authors.forename: Erika Oliveira
authors.initials: EO
authors.lastname: de Almeida
authors.forename: Eduardo Passos
authors.initials: EP
authors.lastname: Rocha
authors.forename: Wirley Gonçalves
authors.initials: WG
authors.lastname: Assunção
authors.forename: Amílcar Chagas Freitas
authors.initials: AC
authors.lastname: Júnior
authors.forename: Rodolfo Bruniera
authors.initials: RB
authors.lastname: Anchieta
mesh_terms: D001696:Biomechanical Phenomena; D002508:Cephalometry; D003198:Computer Simulation; D003724:Dental Arch / Q000033:anatomy & histology / Q000502:physiology; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation; D003826:Denture, Complete, Lower; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007575:Jaw, Edentulous / Q000473:pathology / Q000503:physiopathology; D008334:Mandible / Q000033:anatomy & histology* / Q000502:physiology; D008954:Models, Biological; D016348:Osseointegration / Q000502:physiology; D013314:Stress, Mechanical
chemical_list: D015921:Dental Implants