title: Can cement film thickness influence bond strength and fracture resistance of fiber reinforced composite posts?
abstract: OBJECTIVE
  This study compared the influence of cement film thickness (CFT) on bond strength (BS) and fracture resistance (FR) of fiber-reinforced composite (FRC) posts to root canal.
  
  
  METHODS
  One hundred bovine incisors were used for BS and FR analysis (n = 10) and distributed into five experimental groups according to FRC post diameters (WhitePost DC no. 0.5, no. 1, no. 2, no. 3, no. 4), leading to five different CFTs. The canals were prepared using drill no. 4 provided by the post manufacturer and irrigated with 2.5% NaOCl. After conditioning (24% H2O2/5 min) and silanization, posts were cemented with resin cement. BS was evaluated using push-out test and FR using the compression test at 45°. A stereomicroscope was used to measure CFT and to analyze failure pattern. BS data were subjected to two-way ANOVA and Scheffé test for contrast (α = 0.05); FR data were subjected to one-way ANOVA.
  
  
  RESULTS
  BS was significantly affected by CFT, as the most well-adapted post achieved the highest values (p < 0.05). BS was similar for all root thirds. CFT did not affect fracture resistance. No root fractures were observed.
  
  
  CONCLUSIONS
  A FRC post well adapted to the root canal results in higher BS values. Different CFTs did not influence the FR of teeth restored with FRC posts.
  
  
  CONCLUSIONS
  The results indicate that post retention is improved when a well-adapted post is used, although this has not been critical to fracture resistance.
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil.
authors: Alice Gonçalves
authors: AG
authors: Penelas
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil.
authors: Valery Martins
authors: VM
authors: Piedade
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil.
authors: Ana Carolina Oliveira da Silva
authors: AC
authors: Borges
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil.
authors: Laiza Tatiana
authors: LT
authors: Poskus
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil.
authors: Eduardo Moreira
authors: EM
authors: da Silva
authors: Analytical Laboratory of Restorative Biomaterials (LABiom-R), School of Dentistry, Federal Fluminense University, Rua Mario Santos Braga, nº30, 3º andar Campus do Valonguinho, Centro, Niterói, Rio de Janeiro, CEP 24.020-140, Brazil. jgag@vm.uff.br.
authors: José Guilherme Antunes
authors: http://orcid.org/0000-0002-1359-4720
authors: JG
authors: Guimarães
mesh_terms: D000818:Animals; D002417:Cattle; D003188:Composite Resins; D005899:Glass Ionomer Cements; D006861:Hydrogen Peroxide; D008422:Materials Testing; D011176:Post and Core Technique; D019279:Resin Cements
chemical_list: D003188:Composite Resins; D005899:Glass Ionomer Cements; D019279:Resin Cements; D006861:Hydrogen Peroxide
keywords: Bond strength; Cement film thickness; Fiber posts; Fracture resistance