title: Tensile bond strength of cast commercially pure titanium and cast gold-alloy posts and cores cemented with two luting agents.
abstract: BACKGROUND
  In vitro studies on the retentive strengths of various cements used to retain posts have reported conflicting results.
  
  
  OBJECTIVE
  The purpose of this study was to compare the tensile strength of commercially pure titanium and type III cast gold-alloy posts and cores cemented with zinc phosphate or resin cement.
  
  
  METHODS
  Forty-two extracted human canines were endodontically treated. The root preparations were accomplished using Largo reamers (10 mm in depth and 1.7 mm in diameter). Acrylic resin patterns for the posts and cores were made, and specimens were cast in commercially pure titanium and in type III gold alloy (n=7). Fourteen titanium cast posts and cores were submitted to surface treatment with Kroll acid solution and to scanning electron microscopy (SEM), before and after acid etching. The groups (n=7) were cemented with zinc phosphate cement or resin cement (Panavia F). Tensile strengths were measured in a universal testing machine at a crosshead speed of 0.5 mm/min. The results (Kgf) were statistically analyzed by 2-way ANOVA (alpha=.05).
  
  
  RESULTS
  The 2-way ANOVA indicated that there were no significant differences among the groups tested. Retentive means for zinc phosphate and Panavia F cements were statistically similar. The bond strength was not influenced by the alloy, the luting material, or the etching treatment. SEM analysis indicated that the etched surfaces were smoother than those that did not receive surface treatment, but this fact did not influence the results.
  
  
  CONCLUSIONS
  Commercially pure titanium cast posts and cores cemented with zinc phosphate and resin cements demonstrated similar mean tensile retentive values. Retentive values were also similar to mean values recorded for cast gold-alloy posts and cores cemented with zinc phosphate cement and resin cements.
authors.affiliation: Dental Materials and Prosthesis Department, Ribeirao Preto School of Dentistry, University of Sao Paulo, Sao Paulo, Brazil.
authors.forename: Luiz Ricardo
authors.initials: LR
authors.lastname: Menani
authors.forename: Ricardo Faria
authors.initials: RF
authors.lastname: Ribeiro
authors.forename: Rossana Pereira de Almeida
authors.initials: RP
authors.lastname: Antunes
mesh_terms: D000134:Acid Etching, Dental; D002484:Cementation; D001840:Dental Bonding; D003734:Dental Casting Investment / Q000737:chemistry*; D003738:Dental Cements / Q000737:chemistry*; D003764:Dental Materials / Q000737:chemistry*; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D006047:Gold Alloys / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D011176:Post and Core Technique; D019279:Resin Cements / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D013314:Stress, Mechanical; D013499:Surface Properties; D013718:Tensile Strength; D014025:Titanium / Q000737:chemistry*; D019553:Tooth, Nonvital / Q000628:therapy; D015036:Zinc Phosphate Cement / Q000737:chemistry
chemical_list: D003734:Dental Casting Investment; D003738:Dental Cements; D003764:Dental Materials; D006047:Gold Alloys; C438843:Panavia-Fluoro; D019279:Resin Cements; D015036:Zinc Phosphate Cement; D014025:Titanium