title: Numerical fatigue 3D-FE modeling of indirect composite-restored posterior teeth.
abstract: OBJECTIVE
  In restored teeth, stresses at the tooth-restoration interface during masticatory processes may fracture the teeth or the restoration and cracks may grow and propagate. The aim was to apply numerical methodologies to simulate the behavior of a restored tooth and to evaluate fatigue lifetimes before crack failure.
  
  
  METHODS
  Using a CAD-FEM procedure and fatigue mechanic laws, the fatigue damage of a restored molar was numerically estimated. Tessellated surfaces of enamel and dentin were extracted by applying segmentation and classification algorithms, to sets of 2D image data. A user-friendly GUI, which enables selection and visualization of 3D tessellated surfaces, was developed in a MatLab(®) environment. The tooth-boundary surfaces of enamel and dentin were then created by sweeping operations through cross-sections. A class II MOD cavity preparation was then added into the 3D model and tetrahedral mesh elements were generated. Fatigue simulation was performed by combining a preliminary static FEA simulation with classical fatigue mechanical laws.
  
  
  RESULTS
  Regions with the shortest fatigue-life were located around the fillets of the class II MOD cavity, where the static stress was highest.
  
  
  CONCLUSIONS
  The described method can be successfully adopted to generate detailed 3D-FE models of molar teeth, with different cavities and restorative materials. This method could be quickly implemented for other dental or biomechanical applications.
authors.affiliation: Department of Restorative Dentistry, School of Dentistry, University of Naples Federico II, V.S. Pansini 5, 80131 Naples, Italy. pietausi@unina.it
authors.forename: Pietro
authors.initials: P
authors.lastname: Ausiello
authors.forename: Pasquale
authors.initials: P
authors.lastname: Franciosa
authors.forename: Massimo
authors.initials: M
authors.lastname: Martorelli
authors.forename: David C
authors.initials: DC
authors.lastname: Watts
mesh_terms: D000465:Algorithms; D001696:Biomechanical Phenomena; D003188:Composite Resins / Q000737:chemistry*; D003198:Computer Simulation; D017076:Computer-Aided Design; D003737:Dental Cavity Preparation / Q000145:classification; D003738:Dental Cements / Q000737:chemistry; D003743:Dental Enamel / Q000502:physiology; D003764:Dental Materials / Q000737:chemistry*; D003793:Dental Restoration, Permanent / Q000145:classification / Q000379:methods*; D003804:Dentin / Q000502:physiology; D055119:Elastic Modulus; D020342:Finite Element Analysis; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008409:Mastication; D008422:Materials Testing; D008954:Models, Biological; D008963:Molar / Q000502:physiology*; D013314:Stress, Mechanical; D014082:Tooth Fractures / Q000503:physiopathology
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials