title: Morphological analysis of glass, carbon and glass/carbon fiber posts and bonding to self or dual-cured resin luting agents.
abstract: OBJECTIVE
  The aim of this study was to evaluate the morphology of glass (GF), carbon (CF) and glass/carbon (G/CF) fiber posts and their bond strength to self or dual-cured resin luting agents.
  
  
  METHODS
  Morphological analysis of each post type was conducted under scanning electron microscopy (SEM). Bond strength was evaluated by microtensile test after bisecting the posts and re-bonding the two halves with the luting agents. Data were subjected to two-way ANOVA and Tukey's test (alpha=0.05). Failure modes were evaluated under optical microscopy and SEM.
  
  
  RESULTS
  GF presented wider fibers and higher amount of matrix than CF, and G/CF presented carbon fibers surrounded by glass fibers, and both involved by matrix. For CF and GF, the dual-cured material presented significantly higher (p<0.05) bond strength than the self-cured agent. For the dual agent, CF presented similar bond strength to GF (p>0.05), but higher than that of G/CF (p<0.05). For the self-cured agent, no significant differences (p>0.05) were detected, irrespective of the post type. For GF and G/CF, all failures were considered mixed, while a predominance of adhesive failures was detected for CF.
  
  
  CONCLUSIONS
  The bonding between fiber posts and luting agents was affected by the type of fibers and polymerization mode of the cement. When no surface treatment of the post is performed, the bonding between glass fiber post and dual-cured agent seems to be more reliable.
authors: Department of Prosthodontics and Periodontics, Piracicaba Dental School, State University of Campinas, Piracicaba, SP, Brazil. aospazzin@yahoo.com.br
authors: Aloísio Oro
authors: AO
authors: Spazzin
authors: Rafael Ratto
authors: RR
authors: de Moraes
authors: Doglas
authors: D
authors: Cecchin
authors: Ana Paula
authors: AP
authors: Farina
authors: Bruno
authors: B
authors: Carlini-Júnior
authors: Lourenço
authors: L
authors: Correr-Sobrinho
mesh_terms: D017609:Barium Compounds / Q000737:chemistry; D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D002244:Carbon / Q000737:chemistry*; D000077482:Carbon Fiber; D001840:Dental Bonding; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D003799:Dental Stress Analysis; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011092:Polyethylene Glycols / Q000737:chemistry; D011109:Polymethacrylic Acids / Q000737:chemistry; D011176:Post and Core Technique / Q000295:instrumentation*; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D017609:Barium Compounds; D000077482:Carbon Fiber; D003764:Dental Materials; D011109:Polymethacrylic Acids; C462240:RelyX ARC; D019279:Resin Cements; C102738:barium glass filler; C009753:fiberglass; C020946:triethylene glycol dimethacrylate; D011092:Polyethylene Glycols; D017438:Bisphenol A-Glycidyl Methacrylate; D002244:Carbon; D012822:Silicon Dioxide