title: Standard of disocclusion in complete dentures supported by implants without free distal ends: analysis by the finite elements method.
abstract: OBJECTIVE
  The occlusal patterns are key requirements for the clinical success of oral rehabilitation supported by implants. This study compared the stresses generated by the disocclusion in the canine guide occlusion (CGO) and bilateral balanced occlusion (BBO) on the implants and metallic infrastructure of a complete Brånemark protocol-type denture modified with the inclusion of one posterior short implant on each side.
  
  
  METHODS
  A three-dimensional model simulated a mandible with seven titanium implants as pillars, five of them installed between the mental foramen and the two posterior implants, located at the midpoint of the occlusal surface of the first molar. A load of 15 N with an angle of 45° was applied to a tooth or distributed across three teeth to simulate the CGO or BBO, respectively. The commercial program ABAQUS® was used for the model development, before and after the processing of the data. The results were based on a linear static analysis and were used to compare the magnitude of the equivalent stress for each of the simulations.
  
  
  RESULTS
  The results showed that the disocclusion in CGO generated higher stresses concentrated on the working side in the region of the short implant. In BBO, the stresses were less intense and more evenly distributed on the prosthesis. The maximum stress found in the simulation of the disocclusion in CGO was two times higher than that found in the simulation of the BBO. The point of maximum stress was located in the neck of the short implant on the working side.
  
  
  CONCLUSIONS
  Under the conditions of this study, it was concluded that the BBO pattern was more suitable than CGO for the lower complete denture supported by implants without free distal ends.
authors.affiliation: Dental School, Federal University of Minas Gerais, Belo Horizonte, MG, Brazil. gustavodgreco@yahoo.com.br
authors.forename: Gustavo Diniz
authors.initials: GD
authors.lastname: Greco
authors.forename: Estevam Barbosa de
authors.initials: EB
authors.lastname: Las Casas
authors.forename: Tulimar P Machado
authors.initials: TP
authors.lastname: Cornacchia
authors.forename: Cláudia Silami de
authors.initials: CS
authors.lastname: Magalhães
authors.forename: Allyson Nogueira
authors.initials: AN
authors.lastname: Moreira
mesh_terms: D001696:Biomechanical Phenomena; D003198:Computer Simulation; D015921:Dental Implants; D003767:Dental Occlusion, Balanced / Q000592:standards*; D019094:Dental Prosthesis, Implant-Supported; D003799:Dental Stress Analysis; D003826:Denture, Complete, Lower; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D008954:Models, Biological; D013314:Stress, Mechanical; D014025:Titanium / Q000737:chemistry
chemical_list: D015921:Dental Implants; D014025:Titanium