title: Effect of short glass fiber/filler particle proportion on flexural and diametral tensile strength of a novel fiber-reinforced composite.
abstract: OBJECTIVE
  To evaluate the effect of glass fiber/filler particles proportion on flexural strength and diametral tensile strength of an experimental fiber-reinforced composite.
  
  
  METHODS
  Four experimental groups (N=10) were created using an experimental short fiber-reinforced composite, having as a factor under study the glass fiber (F) and filler particle (P) proportion: F22.5/P55 with 22.5 wt% of fiber and 55 wt% of filler particles; F25/P52.5 with 25 wt% of fiber and 52.5 wt% of filler particles; F27.5/P50 with 27.5 wt% of fiber and 50 wt% of filler particles; F30/P47.5 with 30 wt% of fiber and 47.5 wt% of filler particles. The experimental composite was made up by a methacrylate-based resin (50% Bis-GMA and 50% TEGDMA). Specimens were prepared for Flexural Strength (FS) (25 mm × 2 mm × 2 mm) and for Diametral Tensile Strength (DTS) (3×6 Ø mm) and tested at 0.5 mm/min in a universal testing machine.
  
  
  RESULTS
  The results (in MPa) showed significance (different superscript letters mean statistical significant difference) for FS (p<0.009) and DTS (p<0.001)--FS results: F22.5/P55: 217.24±20.64(B); F25/P52.5: 245.77±26.80(AB); F27.5/P50: 246.88±32.28(AB); F30/P47.5: 259.91±26.01(A). DTS results: F22.5/P55: 21.82±4.42(B); F25/P52.5: 22.00±7.40(B); F27.5/P50: 18.63±4.41(B); F30/P47.5: 31.05±2.97(A). In SEM analysis, areas without fiber reinforcement demonstrated to be more prone to the presence of bubbles and crack development. The group F30/P47.5 showed areas with a great quantity of fibers without empty spaces for crack propagation.
  
  
  CONCLUSIONS
  Increasing fiber content results in higher flexural and diametral tensile strength of an experimental composite reinforced with glass fibers.
authors.affiliation: Department of Restorative Dentistry and Dental Materials, Dentistry School, Federal University of Goiás, Goiânia, Goiás, Brazil. Electronic address: rbfonseca.ufg@gmail.com.
authors.forename: Rodrigo Borges
authors.initials: RB
authors.lastname: Fonseca
authors.affiliation: Dental School, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Letícia Nunes
authors.initials: LN
authors.lastname: de Almeida
authors.affiliation: Dental School, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Gustavo Adolfo Martins
authors.initials: GA
authors.lastname: Mendes
authors.affiliation: Dental School, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Amanda Vessoni Barbosa
authors.initials: AV
authors.lastname: Kasuya
authors.affiliation: Dental School, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Isabella Negro
authors.initials: IN
authors.lastname: Favarão
authors.affiliation: Dental School, Federal University of Goiás, Goiânia, Goiás, Brazil.
authors.forename: Marcella Silva
authors.initials: MS
authors.lastname: de Paula
mesh_terms: D000180:Acrylic Resins; D003188:Composite Resins; D003764:Dental Materials; D003799:Dental Stress Analysis; D005898:Glass; D008689:Methacrylates; D011140:Polyurethanes; D013314:Stress, Mechanical; D013718:Tensile Strength
chemical_list: D000180:Acrylic Resins; C029012:Composite Dental Resin; D003188:Composite Resins; D003764:Dental Materials; D008689:Methacrylates; D011140:Polyurethanes; C009753:fiberglass
keywords: Diametral tensile strength; Fiber-reinforced composite; Filler particles; Flexural strength; Glass fiber