title: Influence of cavity design preparation on stress values in maxillary premolar: a finite element analysis.
abstract: OBJECTIVE
  To analyze the influence of cavity design preparation on stress values in three-dimensional (3D) solid model of maxillary premolar restored with resin composite.
  
  
  METHODS
  3D solid model of maxillary second premolar was designed using computed-tomography (CT) data. Based on a factorial experiment, 9 different mesio-occlusal-distal (MOD) cavity designs were simulated, with three cavity wall thicknesses (1.5 mm, 2.25 mm, 3.0 mm), and three cusp reduction procedures (without cusp reduction, 2.0 mm palatal cusp reduction, 2.0 mm palatal and buccal cusp reduction). All MOD cavities were simulated with direct resin composite restoration (Gradia Direct Posterior, GC, Japan). Finite element analysis (FEA) was used to calculate von Mises stress values.
  
  
  RESULTS
  The von Mises stresses in enamel, dentin, and resin composite were 79.3-233.6 MPa, 26.0-32.9 MPa, and 180.2-252.2 MPa, respectively. Considering the influence of cavity design parameters, cuspal reduction (92.97%) and cavity wall thickness (3.06%) significantly (P<0.05) determined the magnitude of stress values in enamel. The influence of cavity design parameters on stress values in dentin and resin composite was not significant. When stresses for enamel, dentine, and resin composite were considered all together, palatal cusp coverage was revealed as an optimal option. Cavity wall thickness did not show a significant effect on stress values.
  
  
  CONCLUSIONS
  Based on numerical simulations, a palatal cusp reduction could be suggested for revealing lower stress values in dental tissues and restorative material. This type of cavity design should contribute to better biomechanical behavior of tooth-restoration complex, consequently providing the long-lasting clinical results.
authors.affiliation: University of Novi Sad, Faculty of Medicine, School of Dentistry, Hajduk Veljkova 12, 21000 Novi Sad, Serbia. ivanakantardzic@gmail.com
authors.forename: Ivana
authors.initials: I
authors.lastname: Kantardzić
authors.forename: Darko
authors.initials: D
authors.lastname: Vasiljević
authors.forename: Larisa
authors.initials: L
authors.lastname: Blazić
authors.forename: Ognjan
authors.initials: O
authors.lastname: Luzanin
mesh_terms: D001641:Bicuspid; D001696:Biomechanical Phenomena; D003188:Composite Resins / Q000737:chemistry*; D003737:Dental Cavity Preparation / Q000379:methods*; D003743:Dental Enamel; D003764:Dental Materials; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D003804:Dentin; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional; D007564:Japan; D008437:Maxilla; D019228:Tooth Crown
chemical_list: D003188:Composite Resins; D003764:Dental Materials