title: Microleakage under ceramic flash-free orthodontic brackets after thermal cycling.
abstract: OBJECTIVE
  To compare microleakage under 3M Unitek's APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling.
  
  
  METHODS
  Forty freshly extracted human maxillary premolars were randomly divided into two groups and bonded with either a Flash-Free bracket or a PLUS bracket. After bonding, the samples were incubated in a water bath at 37°C for 24 hours and thermocycled for 5000 cycles between 5°C and 50°C. All teeth were immersed in a 2% methylene blue solution for 24 hours, embedded in acrylic and sectioned in a buccolingual direction at approximately the center of the bracket. Microleakage was observed at the enamel-adhesive interface from the occlusal and gingival margins of the bracket base. Statistical analysis was conducted using the Mann-Whitney U-test.
  
  
  RESULTS
  The median microleakage was higher in the Flash-Free group, but the difference between the two groups was not statistically significant (P > .05).
  
  
  CONCLUSIONS
  In a laboratory setting, there is no significant difference between the extent of microleakage under the APC Flash-Free Adhesive Coated System bracket and the APC PLUS Adhesive Coated System bracket after thermal cycling.
authors.forename: Julia
authors.initials: J
authors.lastname: Kim
authors.forename: Georgios
authors.initials: G
authors.lastname: Kanavakis
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Finkelman
authors.forename: Moonyoung
authors.initials: M
authors.lastname: Lee
mesh_terms: D002516:Ceramics; D003188:Composite Resins; D001840:Dental Bonding; D003763:Dental Leakage; D006801:Humans; D008422:Materials Testing; D016910:Orthodontic Brackets; D011897:Random Allocation; D019279:Resin Cements
chemical_list: D003188:Composite Resins; D019279:Resin Cements
keywords: Adhesive; Flash-free; Microleakage; Thermal cycling