title: Influence of C-factor on the microtensile bond strength between fiber posts and resin luting agents.
abstract: OBJECTIVE
  To propose an experimental model for assessing the interfacial strength between post and luting agent under clinically relevant conditions of post space diameter and cement layer thickness.
  
  
  METHODS
  DentinPost (Komet, DP) and GC (GC) glass fiber posts were tested. A sample of 22 posts per type was randomly subdivided into two equal groups based on the material for cementation: Panavia F 2.0 (Kuraray, PF) and MultiCore Flow (Ivoclar Vivadent, MF). Within each group, 2 subgroups were defined depending on the procedure for specimen preparation. In subgroup A (NO-M), the resin cement was incrementally stratified around a post centered within a plastic matrix until the latter was filled. In subgroup B (M), first a mold of resin cement with an artificial post space was created. Then, using the same cement, the post was luted into the dowel space. Microtensile beams were cut and loaded to measure post/cement interfacial strengths. For statistical analysis of the data, Kruskall-Wallis ANOVA was applied, followed by Dunn's Multiple Range test (p < 0.05).
  
  
  RESULTS
  Bond strengths in MPa were (median; 25th-75th percentile): DP/PF/M 4.5; 3.1-7.4; DP/PF/NO-M 9.2; 5.8-12.4; DP/MF/M 14.2; 10.2-20-6; DP/MF/NO-M 16.5; 13.1-21.7; GC/PF/M 7.6; 3.3-11.7; GC/PF/NO-M 7.8; 5.1-11-9; GC/MF/M 16.7; 14.3-3-22; GC/MF/NOM 20.4; 15.6-24. Irrespective of post type and of specimen preparation procedure, with or without mold, significantly higher bond strengths were measured for MF. On both post types, both cements achieved similar interfacial strengths regardless of the C-factor.
  
  
  CONCLUSIONS
  The influence of a clinically relevant C-factor on the adhesion of resin cements to glass fiber posts was not statistically significant.
authors.affiliation: aLecturer, Department of General Dentistry, College of Stomatology, Fourth Military Medical University, Xian, PR China.
authors.forename: Ying-jie
authors.initials: YJ
authors.lastname: Wang
authors.forename: Ling
authors.initials: L
authors.lastname: Zhang
authors.forename: Ji-hua
authors.initials: JH
authors.lastname: Chen
authors.forename: Cecilia
authors.initials: C
authors.lastname: Goracci
authors.forename: Marco
authors.initials: M
authors.lastname: Ferrari
mesh_terms: D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding; D003738:Dental Cements / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D004853:Epoxy Resins / Q000737:chemistry; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry*; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D003188:Composite Resins; D003738:Dental Cements; D003764:Dental Materials; D004853:Epoxy Resins; D008689:Methacrylates; C076808:Monobond S; C509715:MultiCore Flow; C438843:Panavia-Fluoro; D019279:Resin Cements; D012117:Resins, Synthetic; C009753:fiberglass