title: Effect of tin-chloride pretreatment on bond strength of two adhesive systems to dentin.
abstract: OBJECTIVE
  To determine the effect on resin composite-to-dentin bond strength of incorporation of an acidic tin-chloride pretreatment in two adhesive systems.
  
  
  METHODS
  Human molars were ground to expose mid-coronal dentin. For microtensile bond strength (μTBS) testing, dentin was treated with Optibond FL or Clearfil SE according to one of six protocols (n = 22/group). Group 1: Phosphoric acid etching, Optibond FL Prime, Optibond FL Adhesive (manufacturer's instructions; control); Group 2: Tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 3: Phosphoric acid etching, tin-chloride pretreatment, Optibond FL Prime, Optibond FL Adhesive; Group 4: Clearfil SE Primer, Clearfil SE Bond (manufacturer's instructions; control); Group 5: Phosphoric acid etching, Clearfil SE Primer, Clearfil SE Bond; and Group 6: Tin-chloride pretreatment, Clearfil SE Primer, Clearfil SE Bond. The molars were then built up with resin composite (Clearfil Majesty Esthetic). After storage (1 week, 100 % humidity, 37 °C) the μTBS was measured and failure mode was determined. Additionally, pretreated dentin surfaces were evaluated using SEM and EDX. The μTBS results were analyzed statistically by a Welch Two Sample t-test and a Kruskal-Wallis test followed by exact Wilcoxon rank sum tests with Bonferroni-Holm adjustment for multiple testing (α = 0.05).
  
  
  RESULTS
  When Optibond FL was used, partial or total replacement of phosphoric acid with tin-chloride decreased μTBS significantly. In contrast, when Clearfil SE was used, inclusion of a tin-chloride pretreatment in the adhesive procedure increased μTBS significantly.
  
  
  CONCLUSIONS
  Tin-chloride pretreatment had a beneficial influence on the bond promoting capacity of the MDP-containing adhesive system Clearfil SE.
authors.affiliation: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Freiburgstrasse 7, CH-3010, Bern, Switzerland, anne.peutzfeldt@zmk.unibe.ch.
authors.forename: Anne
authors.initials: A
authors.lastname: Peutzfeldt
authors.forename: Tamara
authors.initials: T
authors.lastname: Koch
authors.forename: Carolina
authors.initials: C
authors.lastname: Ganss
authors.forename: Simon
authors.initials: S
authors.lastname: Flury
authors.forename: Adrian
authors.initials: A
authors.lastname: Lussi
mesh_terms: D003738:Dental Cements; D003804:Dentin / Q000737:chemistry*; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D017971:Tin Compounds / Q000737:chemistry*
chemical_list: D003738:Dental Cements; D017971:Tin Compounds; C023599:stannous chloride