title: Assessment of post-contamination treatments affecting different bonding stages to dentin.
abstract: OBJECTIVE
  To assess the effect of cleansing treatments following saliva and blood contamination at different bonding stages to dentin.
  
  
  METHODS
  Labial surfaces of 168 permanent maxillary central incisors were ground flat exposing superficial dentin. Specimens were divided into: uncontaminated control (A), contamination after etching (B), contamination after adhesive application (C), contamination after adhesive polymerization (D). Groups were further subdivided according to cleansing treatments into: rinsing (B1, C1, D1), re-etching (B2, D3), sodium hypochlorite application (B3), ethyl alcohol application (C2), acetone application (C3), rinsing and rebonding (D2), re-etching and rebonding (D4). Composite microcylinders were bonded to treated substrates and shear loaded micro-shear bond strength (μSBS) until failure and treated surfaces were examined with scanning electron microscope. Debonded surfaces were classified as adhesive, cohesive or mixed failure. The data were analyzed using one-way ANOVA and Tukey's post hoc test.
  
  
  RESULTS
  The μSBS values were ranked as follow; Group B: A > B3 > B2 > B1 > B, Group C: A > C3 > C2 > C1 > C, Group D: A > D4 > D1 = D2 ≥ D3. Debonded surfaces showed adhesive failure in Group B while cohesive failure in Groups C and D.
  
  
  CONCLUSIONS
  Cleansing treatments differ according to bonding step; re-etching then rebonding suggested if etched substrate or polymerized adhesive were contaminated while acetone application decontaminated affected unpolymerized adhesive.
authors.affiliation: Department of Operative Dentistry, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt.
authors.forename: Dina
authors.initials: D
authors.lastname: Elkassas
authors.affiliation: Department of Pediatric Dentistry and Dental Public Health, Faculty of Oral and Dental Medicine, Misr International University, Cairo, Egypt.
authors.forename: Abla
authors.initials: A
authors.lastname: Arafa
keywords: Acetone; bonding stages; contamination; dentin; re-etching