title: Effects of blood contamination on resin-resin bond strength.
abstract: OBJECTIVE
  Incremental placement and curing of resin composites has been recommended. However, this requires longer operating time, and therefore, increased risk of contamination. The purpose of this study was to evaluate the effects of blood contamination on microtensile bond strengths (microTBS) between resin interfaces and to determine the best decontamination method to re-establish the original resin-resin bond strength.
  
  
  METHODS
  The top surfaces of 64, 4-mm composite blocks (Z-250, Renew, APX, Pertac II) were untreated as the control, or were treated as follows: blood applied and dried on the surface (Treatment 1), blood applied, rinsed, dried (Treatment 2), blood applied, rinsed, and an adhesive applied (Single Bond, One-Step, Clearfil SE, Prompt L-Pop) (Treatment 3). Fresh composite was applied and light-cured in 2-mm increments. After 24 h storage in water, the specimens were sectioned into 0.7-mm thick slabs, trimmed to a cross-sectional area of 1 mm(2), and loaded to failure at a crosshead speed of 1 mm/min using an Instron universal testing machine. Data were analyzed using two-way ANOVA and Fisher's PLSD test (p<0.05).
  
  
  RESULTS
  Control values ranged from 45.1 MPa for Pertac II to 71.5 MPa for APX. Untreated blood contamination resulted in resin-resin bond strengths of only 1.0-13.1 MPa. Rinsing raised bond strengths to over 40 MPa for each material. Use of an adhesive further increased bond strengths except for Pertac II.
  
  
  CONCLUSIONS
  Rinsing blood from contaminated surfaces increases the resin-resin bond strength significantly and the application of an appropriate adhesive increases the bond strength to control levels.
authors.affiliation: Department of Operative Dentistry, University of North Carolina at Chapel Hill, 302 Brauer Hall, Chapel Hill, NC 27599-7450, USA.
authors.forename: Sigurdur O
authors.initials: SO
authors.lastname: Eiriksson
authors.forename: Patricia N R
authors.initials: PN
authors.lastname: Pereira
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Swift
authors.forename: Harald O
authors.initials: HO
authors.lastname: Heymann
authors.forename: Asgeir
authors.initials: A
authors.lastname: Sigurdsson
mesh_terms: D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D001769:Blood; D003188:Composite Resins; D003666:Decontamination / Q000379:methods; D001840:Dental Bonding; D003799:Dental Stress Analysis; D017220:Dentin-Bonding Agents; D008422:Materials Testing; D008689:Methacrylates; D011897:Random Allocation; D019279:Resin Cements; D013718:Tensile Strength; D014867:Water
chemical_list: C103506:Bis-GMA, BPDM, HEMA dental-bonding resin; C438313:Clearfil SE Bond; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D008689:Methacrylates; C408584:Prompt L-Pop; D019279:Resin Cements; C115612:single bond; D014867:Water; D017438:Bisphenol A-Glycidyl Methacrylate