title: Influence of occlusal contact area on cusp defection and stress distribution.
abstract: OBJECTIVE
  The purpose of this study was to evaluate the effect of occlusal contact area for loading on the cuspal defection and stress distribution in a first premolar restored with a high elastic modulus restorative material.
  
  
  METHODS
  The Rhinoceros 4.0 software was used for modeling the three-dimensional geometries of dental and periodontal structures and the inlay restoration. Thus, two different models, intact and restored teeth with three occlusal contact areas, 0.1, 0.5 and 0.75 mm(2), on enamel at the occlusal surface of buccal and lingual cusps. Finite element analysis (FEA) was performed with the program ANSYS (Workbench 13.0), which generated a mesh with tetrahedral elements with greater refinement in the regions of interest, and was constrained at the bases of cortical and trabecular bone in all axis and loaded with 100 N normal to each contact area.
  
  
  RESULTS
  To analysis of maximum principal stress, the smaller occlusal contact area showed greater compressive stress in region of load application for both the intact and inlay restored tooth. However, tensile stresses at the occlusal isthmus were similar for all three tested occlusal contact areas (60 MPa). To displacement of the cusps was higher for teeth with inlay (0.46-0.48 mm). For intact teeth, the smaller contact area showed greater displacement (0.10 mm). For teeth with inlays, the displacement of the cusps were similar in all types of occlusal area.
  
  
  CONCLUSIONS
  Cuspal displacement was higher in the restored tooth when compared to the intact tooth, but there were no significant variations even with changes in the occlusal contact area. RELEVANCE CLINICAL: Occlusal contacts have a great influence on the positioning of teeth being able to maintain the position and stability of the mandible. Axial loads would be able to generate more uniform stress at the root presenting a greater concentration of load application in the point and the occlusal surface. Thus, is necessary to analyze the relationship between these occlusal contacts as dental wear and subsequent occlusal interferences.
authors.affiliation: PhD Student, School of Dentistry, Institute of Sciences and Technology Universidade Estadual Paulista, São José dos Campos, São Paulo, Brazil.
authors.forename: Anna Karina Figueiredo
authors.initials: AK
authors.lastname: Costa
authors.affiliation: PhD Student, School of Dentistry, Institute of Sciences and Technology Universidade Estadual Paulista, São José dos Campos, São Paulo, Brazil.
authors.forename: Thaty Aparecida
authors.initials: TA
authors.lastname: Xavier
authors.affiliation: PhD Student, School of Dentistry, Institute of Sciences and Technology Universidade Estadual Paulista, São José dos Campos, São Paulo, Brazil.
authors.forename: Tarcisio José Arruda
authors.initials: TJ
authors.lastname: Paes-Junior
authors.affiliation: PhD Student, School of Dentistry, Institute of Sciences and Technology Universidade Estadual Paulista, São José dos Campos, São Paulo, Brazil.
authors.forename: Oswaldo Daniel
authors.initials: OD
authors.lastname: Andreatta-Filho
authors.affiliation: PhD Student, Av. Eng Francisco José Longo 777, Post Code: 12245-000, São José dos Campos, São Paulo, Brazil, Phone: +55 12 39479363, e-mail: aleborges@fosjc.unesp.br.
authors.forename: Alexandre Luiz Souto
authors.initials: AL
authors.lastname: Borges
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry; D001641:Bicuspid / Q000033:anatomy & histology*; D001696:Biomechanical Phenomena; D001732:Bite Force; D003198:Computer Simulation; D017076:Computer-Aided Design; D003743:Dental Enamel / Q000033:anatomy & histology; D003766:Dental Occlusion; D003776:Dental Porcelain / Q000737:chemistry*; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007284:Inlays; D008422:Materials Testing; D008954:Models, Biological; D017680:Potassium Compounds / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D019228:Tooth Crown / Q000033:anatomy & histology*
chemical_list: D000538:Aluminum Silicates; D017680:Potassium Compounds; D003776:Dental Porcelain; C016447:feldspar
keywords: Andreatta-Filho OD; Borges ALS. Influence of Occlusal Contact Area on Cusp Defection and Stress Distribution. J Contemp Dent Pract 2014;15(6):699-704. Source of support: Nil Conflict of interest: None.; Cuspal defection; Finite element analyze; Occlusal contact area; Occlusal loading. How to cite this article: Costa AKF; Paes-Junior TJA; Xavier TA