title: Effect of Finishing Time on Microleakage at the Composite-Repair Interface.
abstract: BACKGROUND
  Repair is a conservative treatment of defective composite restoration. Sealing the repair interface is a critical factor to achieve successful repaired restorations.
  
  
  OBJECTIVE
  The aim of this study was to evaluatethe effect of three finishing times on the microleakage at the composite-repair interface.
  
  
  METHODS
  Eighty composite specimens (Z250) were made and aged for eight weeks in water. They were randomly divided into four groups. In the control group, repairing was done with no surface treatment and using bonding agent. In groups 2 to 4, the specimens were repaired following roughening, etching and use of Adper Single Bond, and finished immediately, after 20 minutes and after 24 hours, respectively. After thermocycling, the microleakage at the repair interface was assessed using dye-penetration technique. The results were analyzed using Kruskal-Wallis and Mann-Whitney tests (α=0.05).
  
  
  RESULTS
  There was a significant difference among the four groups (P<0.001). The control group with the highest leakage showed a significant difference with the other groups (P<0.05). Immediate finishing showed a significantly higher leakage compared to 20-minute and 24-hour delayed finishing time (P<0.001). The two latter groups had no difference.
  
  
  CONCLUSIONS
  Immediate finishing of the repaired restorations negatively affect the sealing at the repair interface, while 20-minute and 24-hour delayed finishing had no adverse effect on the interface sealing.
authors.affiliation: Oral and Dental Disease Research Center, Department of Operative Dentistry, School of Dentistry, Shiraz University of Medical Sciences, Shiraz, Iran.
authors.forename: Fereshteh
authors.initials: F
authors.lastname: Shafiei
authors.affiliation: Department of Orthodontics, School of Dentistry, Shiraz University of Medical sciences, Shiraz, Iran.
authors.forename: Nazanin
authors.initials: N
authors.lastname: Berahman
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry, Shiraz University of Medical sciences, Shiraz, Iran.
authors.forename: Elmira
authors.initials: E
authors.lastname: Niazi
keywords: Composite Resin; Finishing Time; Microleakage; Repair Interface