title: Influence of Using Clinical Microscope as Auxiliary to Perform Mechanical Cleaning of Post Space: A Bond Strength Analysis.
abstract: BACKGROUND
  The aim of the present study was to evaluate the influence of using a clinical microscope while performing mechanical cleaning of post space walls on the bond strength of a fiberglass post to dentin.
  
  
  METHODS
  Forty-five bovine roots were used. After preparation, roots were filled using gutta-percha and Pulp Canal Sealer (SybronEndo, Orange, CA). Subsequently, for post space preparation, the roots were divided into 3 groups: control (only heat condenser + specific bur of the post system); cleaning without a microscope, mechanical cleaning (after the procedure described in the control group, round burs were used to improve cleaning); and cleaning with a microscope, mechanical cleaning performed with round burs visualized under a clinical microscope. Then, fiberglass posts were cemented. The roots were prepared and evaluated by the push-out test. Data were analyzed using Kruskal-Wallis and Student-Newman-Keuls tests (P < .05). The failure pattern was classified as follows: adhesive between the cement and dentin, adhesive dentin/cement/post, mixed cohesive within dentin, mixed cohesive post, and mixed cohesive post/dentin.
  
  
  RESULTS
  The bond strength values (mean ± standard deviation) were control (cervical 1.17 ± 1.1, middle 0.40 ± 0.3, apical 0.52 ± 0.3, and total 0.95 ± 1.9), cleaning without a microscope (cervical 1.66 ± 2.3, middle 0.65 ± 1.1, apical 0.79 ± 1.2, and total1.04 ± 1.7), and cleaning with a microscope (cervical 3.26 ± 2.8, middle 1.97 ± 3.5, apical 1.85 ± 4.1, and total 2.37 ± 3.5). In the cleaning with a microscope group, the bond strength values were significantly higher than those in the other groups. In all groups, the main failure pattern was adhesive between cement and dentin.
  
  
  CONCLUSIONS
  The use of a clinical microscope while performing mechanical cleaning during post space preparation improved the bond strength of a fiberglass post to dentin.
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Ferreira
authors.affiliation: Division of Endodontics, Department of Dental Clinic, Federal University of Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil. Electronic address: mairapr@hotmail.com.
authors.forename: Maíra
authors.initials: M
authors.lastname: Prado
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Adriana
authors.initials: A
authors.lastname: de Jesus Soares
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Alexandre Augusto
authors.initials: AA
authors.lastname: Zaia
authors.affiliation: Division of Endodontics, Department of Restorative Dentistry, State University of Campinas-UNICAMP, Piracicaba, São Paulo, Brazil.
authors.forename: Francisco José
authors.initials: FJ
authors.lastname: de Souza-Filho
mesh_terms: D000818:Animals; D002417:Cattle; D003738:Dental Cements; D019232:Dental Restoration Failure; D003804:Dentin; D005898:Glass; D006171:Gutta-Percha; D008853:Microscopy / Q000379:methods*; D010895:Pit and Fissure Sealants; D011176:Post and Core Technique
chemical_list: D003738:Dental Cements; D010895:Pit and Fissure Sealants; C009753:fiberglass; D006171:Gutta-Percha
keywords: Bond strength; clinical microscope; mechanical cleaning; post space walls