title: Effect of root canal sealers on bond strength of fibreglass posts cemented with self-adhesive resin cements.
abstract: OBJECTIVE
  This study evaluated the effects of different root canal sealers on the bond strength of a fibreglass post cemented with self-adhesive resin cements.
  
  
  METHODS
  The root canals of 50 extracted maxillary single-rooted canine teeth were prepared with the crown-down technique and randomly divided into five groups according to the sealer used: group 1: control group, gutta-percha points only (no sealer); group 2: AH Plus (resin-based sealer); group 3: self-etch Epiphany (resin-based sealer); group 4: Sealer 26 (calcium hydroxide-based sealer); and group 5: Endomethasone (zinc oxide eugenol-based sealer). The root canals were filled with gutta-percha, the cold lateral compaction technique, except for group 3 where Resilon was used. Post spaces were prepared, and fibreglass posts were cemented with the self-adhesive cement RelyX Unicem. Bonded specimens were sectioned into 1-mm-thick slabs, and a push-out test was performed in a universal machine. Failure modes were observed and classified into five types: (i) adhesive between the post and resin cement; (ii) mixed, with resin cement covering 0-50% of the post diameter; (iii) mixed, with resin cement covering 50-100% of the post surface; (iv) adhesive between resin cement and root canal; and (v) cohesive in dentine. Data of bond strength were submitted to anova and Tukey test (α = 0.05).
  
  
  RESULTS
  No significant difference was detected between control group, AH Plus, Epiphany and Sealer 26 (P > 0.05). The Endomethasone group had significantly lower bond strength values than the other sealers (P < 0.05). The prevalence of mixed fractures and adhesive cement-dentine failure was verified in the eugenol-containing sealer group; in the control group, the resin-based and calcium hydroxide-based sealer groups, the predominant mode of failure was the mixed type.
  
  
  CONCLUSIONS
  Endomethasone interfered negatively with the bond to root dentine; however, AH Plus, Epiphany and Sealer 26 did not interfere in the bond strength of a fibreglass post cemented with self-adhesive resin cements.
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil. dgscecchin@yahoo.com.br
authors.forename: D
authors.initials: D
authors.lastname: Cecchin
authors.forename: A P
authors.initials: AP
authors.lastname: Farina
authors.forename: M A
authors.initials: MA
authors.lastname: Souza
authors.forename: B
authors.initials: B
authors.lastname: Carlini-Júnior
authors.forename: C C R
authors.initials: CC
authors.lastname: Ferraz
mesh_terms: D000704:Analysis of Variance; D002126:Calcium Hydroxide; D003481:Cuspid; D001840:Dental Bonding; D003799:Dental Stress Analysis; D003804:Dentin; D017220:Dentin-Bonding Agents; D005898:Glass; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D019279:Resin Cements; D012387:Root Canal Filling Materials; D012389:Root Canal Obturation / Q000379:methods; D018709:Statistics, Nonparametric; D015035:Zinc Oxide-Eugenol Cement
chemical_list: D017220:Dentin-Bonding Agents; D019279:Resin Cements; D012387:Root Canal Filling Materials; D015035:Zinc Oxide-Eugenol Cement; C009753:fiberglass; D002126:Calcium Hydroxide