title: Effect of Endodontic Retreatment on Push-out Bond Strength and Quality of Fiber Postbonding Interface of Resin Cements.
abstract: OBJECTIVE
  The aim of this study is to evaluate the impact of endodontic retreatment on push-out bond strength and dentin interface of two resin cements used for fiber postcementation during endodontic retreatment.
  
  
  METHODS
  The root canals of 40 extracted human canines were prepared, obturated and divided into four groups (n = 10). Gutta-percha was partially removed and fiber posts were immediately cemented in groups 1 and 2 using Panavia F with ED Primer and RelyX™ U200, respectively. In groups 3 and 4, the root canal access was sealed with temporary restorative cement, specimens were stored for 30 days, endodontically retreated, and fiber posts were cemented using the resin cements applied to groups 1 and 2, respectively. Push-out tests and scanning electron microscopy analyses of different areas were performed. Data from push-out bond strengths were analyzed by one-way analysis of variance and Tukey's tests.
  
  
  RESULTS
  Higher bond strength values were detected in the apical third for group 1 than group 3 (p < 0.05). No differences were observed in other comparisons between the same third of different groups (p > 0.05). Comparisons between different thirds in the same group revealed a higher bond strength in the apical third for group 1. Scanning electron microscopy showed formation of hybrid layer and extensive resin tags in group 1. No hybrid layer was observed in groups 2 and 4.
  
  
  CONCLUSIONS
  Endodontic retreatment had adverse effects on the push-out bond strength and dentinal interface of Panavia F with ED Primer when used for fiber postcementation specifically in the apical third, but not on RelyX™ U200.
  
  
  CONCLUSIONS
  A significant interaction was detected between endodontic retreatment and resin cement, which indicated that endodontic retreatment might adversely affect the push-out bond strength and dentinal interface of Panavia F with ED Primer when used for fiber postcementation specifically in the apical third.
authors.affiliation: Professor, Department of Endodontics, São Leopoldo Mandic Institute and Research Center, São Paulo, Brazil, Phone: +551932725219 e-mail: rinapelegrine@terra.com.br.
authors.forename: Rina Andréa
authors.initials: RA
authors.lastname: Pelegrine
authors.affiliation: Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, São Paulo, Brazil.
authors.forename: Luís Alexandre Maffei Sartini
authors.initials: LA
authors.lastname: Paulillo
authors.affiliation: Department of Endodontics, São Leopoldo Mandic Institute and Research Center, São Paulo, Brazil.
authors.forename: Augusto Shoji
authors.initials: AS
authors.lastname: Kato
authors.affiliation: Department of Endodontics, São Leopoldo Mandic Institute and Research Center, São Paulo, Brazil.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Fontana
authors.affiliation: Department of Restorative Dentistry, Catholic University of Campinas, Campinas, São Paulo, Brazil.
authors.forename: Sérgio Luiz
authors.initials: SL
authors.lastname: Pinheiro
authors.affiliation: Department of Endodontics, São Leopoldo Mandic Institute and Research Center, São Paulo, Brazil.
authors.forename: Alexandre Sigrist
authors.initials: AS
authors.lastname: De Martin
authors.affiliation: Department of Endodontics, São Leopoldo Mandic Institute and Research Center, São Paulo, Brazil.
authors.forename: Carlos Eduardo da Silveira
authors.initials: CE
authors.lastname: Bueno
mesh_terms: D003481:Cuspid; D001840:Dental Bonding; D003804:Dentin; D006171:Gutta-Percha; D006801:Humans; D008422:Materials Testing; D011176:Post and Core Technique; D019279:Resin Cements; D019233:Retreatment
chemical_list: D019279:Resin Cements; D006171:Gutta-Percha
keywords: Bond strength; De Martin AS; Fiber post; Fontana CE; Kato AS; Laboratory research; Paulillo LAMS; Pinheiro SL; Push-out testing; Retreatment. How to cite this article: Pelegrine RA; da Silveira Bueno CE. Effect of Endodontic Retreatment on Push-out Bond Strength and Quality of Fiber Postbonding Interface of Resin Cements. J Contemp Dent Pract 2016;17(1):42-48. Source of support: Nil Conflict of interest: None.