title: The adhesion between prefabricated FRC posts and composite resin cores: microtensile bond strength with and without post-silanization.
abstract: OBJECTIVE
  Aim of the study was to measure the adhesion between two types of translucent prefabricated FRC posts (FRC Postec, Ivoclar-Vivadent, FRC; Light-Post, RTD, LP), and two types of flowable composites used as core materials (UnifilFlow, GC, UF; Tetric Flow, Ivoclar-Vivadent, TF), with or without the application of a silane (Monobond-S, Ivoclar-Vivadent, S) on the post surface.
  
  
  METHODS
  The experimental groups were: 1.1 FRC+UF; 1.2 FRC+S+UF; 1.3 FRC+TF; 1.4 FRC+S+TF: 2.1 LP+UF; 2.2 LP+S+UF; 2.3 LP+TF; 1.4 LP+S+TF. The bond strength at the interface between post and core was measured with the microtensile non-trimming technique. Thirty to thirty-five beam-shaped specimens per group were obtained from cylinders of core material, which had been built up around the post by progressively adding small increments of composite resin. Each specimen was loaded in tension until failure at either one of the two post-core interfaces present in each stick. The differences in interfacial bond strength among the groups were tested for statistical significance with the two-way ANOVA.
  
  
  RESULTS
  The measured bond strengths in MPa were: [table: see text]. The statistical analysis revealed that post-silanization had a significant effect on adhesion (p<0.05). With any combination of post and core materials tested, the application of a silane onto the post surface prior to building up the core significantly increased the post-core bond strength.
  
  
  CONCLUSIONS
  For improved adhesion at the interface between prefabricated FRC posts and composite resin cores, post-silanization is advisable.
authors.affiliation: Department of Dental Materials, University of Siena, Siena, Italy. cecilia.goracci@tin.it
authors.forename: Cecilia
authors.initials: C
authors.lastname: Goracci
authors.forename: Ornella
authors.initials: O
authors.lastname: Raffaelli
authors.forename: Francesca
authors.initials: F
authors.lastname: Monticelli
authors.forename: Beatrice
authors.initials: B
authors.lastname: Balleri
authors.forename: Egidio
authors.initials: E
authors.lastname: Bertelli
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D000268:Adhesiveness; D000704:Analysis of Variance; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding; D003738:Dental Cements; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D004853:Epoxy Resins / Q000737:chemistry; D005898:Glass; D008422:Materials Testing; D011176:Post and Core Technique; D011791:Quartz; D012821:Silanes; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D004853:Epoxy Resins; C076808:Monobond S; D012821:Silanes; C500741:Unifil Core; C009753:fiberglass; C452226:tetric flow composite resin; D011791:Quartz