title: Short fibre-reinforced composite for extensive direct restorations: a laboratory and computational assessment.
abstract: OBJECTIVE
  The objective of the study was to evaluate the effectiveness of a short fibre-reinforced composite (FRC) applied in combination with a conventional filler composite (CFC) on the fatigue resistance, fracture strength, failure mode and stress distribution, for restorations of premolars under two loading angles.
  
  
  METHODS
  Thirty-two inferior premolars received extensive cavities with removal of the lingual cusp. Teeth were restored directly using 'FRC (EverX Posterior, GC) + CFC (G-aenial, GC)' or 'CFC only' and received two fatigue/fracture loadings at two different angles (0°/45°) (n = 8). Data were submitted to two-way ANOVA (α = 5 %) and Tukey test. Failure mode was analysed using SEM. Four 3D finite element (FE) models were constructed and static, linear and elastic analyses were performed. Maximum principal and von Mises stresses were evaluated.
  
  
  RESULTS
  All specimens survived the mechanical fatigue simulation. No statistical difference in fracture resistance was recorded between FRC + CFC and CFC only, considering both loading angles (p = 0.115). However, the 0° loading showed a statistical significant higher strength than the 45° loading (p = 0.000). Failure mode analysis revealed more repairable fractures upon 0° loading, versus more root fractures (unrepairable) upon 45° loading. FE revealed a higher amount of stress upon 45° loading, with tensile stress being imposed to the lingual cervical area.
  
  
  CONCLUSIONS
  The fracture strength was not increased using the FRC. Loading at a 45° decreased significantly the fracture resistance.
  
  
  CONCLUSIONS
  The restoration of extensive cavities in posterior tooth is a challenge for the clinicians and the choice of the material that increases the fracture strength of tooth-restoration complex is required.
authors.affiliation: BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, Belgium.|BMGO, Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven (University of Leuven), Leuven, Belgium.
authors.forename: Bruno Castro Ferreira
authors.initials: BC
authors.lastname: Barreto
authors.affiliation: BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Annelies
authors.initials: A
authors.lastname: Van Ende
authors.affiliation: BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Diogo Pedrollo
authors.initials: DP
authors.lastname: Lise
authors.affiliation: Division of Tridimensional Technologies, Center for Information Technology Renato Archer (DT3D/CTI), Campinas, São Paulo, Brazil.
authors.forename: Pedro Yoshito
authors.initials: PY
authors.lastname: Noritomi
authors.affiliation: BMGO, Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven (University of Leuven), Leuven, Belgium.
authors.forename: Siegfried
authors.initials: S
authors.lastname: Jaecques
authors.affiliation: BMGO, Biomechanics Section (BMe), Department of Mechanical Engineering, KU Leuven (University of Leuven), Leuven, Belgium.
authors.forename: Jos Vander
authors.initials: JV
authors.lastname: Sloten
authors.affiliation: BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: De Munck
authors.affiliation: BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven) & Dentistry, University Hospitals Leuven, Leuven, Belgium. bart.vanmeerbeek@med.kuleuven.be.
authors.forename: Bart
authors.initials: B
authors.lastname: Van Meerbeek
mesh_terms: D001641:Bicuspid; D003188:Composite Resins / Q000737:chemistry*; D003731:Dental Caries / Q000628:therapy*; D019232:Dental Restoration Failure; D003793:Dental Restoration, Permanent; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents / Q000737:chemistry*; D020342:Finite Element Analysis; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing; D013499:Surface Properties
chemical_list: D003188:Composite Resins; D017220:Dentin-Bonding Agents; C000618653:EverX Posterior; C000623314:G-aenial Bond
keywords: Fatigue resistance; Finite element analysis; Fracture strength; Loading angle; Short fibre-reinforced composites