title: Effect of surface treatments and bonding agents on the bond strength of repaired composites.
abstract: BACKGROUND
  An adequate repair procedure depends on high bond strength between the existing composite and the new composite.
  
  
  OBJECTIVE
  To evaluate the effect of surface treatments and bonding procedures on the bond strength of repairs performed 24 hours after composite polymerization.
  
  
  METHODS
  Composite specimens were stored in distilled water at 37 degrees C for 24 hours. Specimens were allocated into 12 groups (N=10) according to the combination of surface treatment (none, air abrasion, diamond bur) and bonding procedure (none, Single Bond after H(3)PO(4) cleansing, Clearfil SE Bond after H(3)PO(4) cleansing, Clearfil SE Bond without H(3)PO(4) cleansing). The ultimate tensile strength (UTS) of the composite was tested in nonrepaired specimens. Twenty-four hours after repair, specimens were sectioned into three slabs and trimmed to an hourglass shape (1 mm(2) area). Slabs were tested under tension and mean bond strengths analyzed with two-way analysis of variance/Tukey and Dunnett tests (alpha=5%).
  
  
  RESULTS
  Two groups resulted in repair bond strengths similar to composite UTS: air abrasion combined with Clearfil SE Bond after H(3)PO(4) cleansing, and air abrasion combined with Clearfil SE Bond without H(3)PO(4) cleansing. Combinations of surface treatments and bonding procedures were not statistically different.
  
  
  CONCLUSIONS
  When repair procedure was performed 24 hours after composite polymerization, different combinations of surface treatments and bonding procedures affected repair bond strength similarly. There was no statistical difference between the repair bond strength of groups air-abraded and bonded with the self-etching system and composite UTS.
  
  
  CONCLUSIONS
  Only air abrasion associated with a self-etching system provided repair bond strength comparable to composite UTS.
authors: Department of Restorative Dentistry, Piracicaba School of Dentistry, UNICAMP, Piracicaba, SP, Brazil.
authors: Andrea Nóbrega
authors: AN
authors: Cavalcanti
authors: Adriano Fonseca
authors: AF
authors: De Lima
authors: Alessandra Rezende
authors: AR
authors: Peris
authors: Fabio Hiroyuki Ogata
authors: FH
authors: Mitsui
authors: Giselle Maria
authors: GM
authors: Marchi
mesh_terms: D020906:Air Abrasion, Dental; D003188:Composite Resins; D001840:Dental Bonding; D045662:Dental Etching / Q000379:methods; D017269:Dental Prosthesis Repair; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis; D044367:Phase Transition; D019279:Resin Cements; D013499:Surface Properties; D013718:Tensile Strength; D019246:Tooth Preparation
chemical_list: D003188:Composite Resins; D019279:Resin Cements; C467914:TPH spectrum