title: Are the low-shrinking composites suitable for orthodontic bracket bonding?
abstract: OBJECTIVE
  To evaluate the shear bond strength (SBS), adhesive remnant index (ARI), and microleakage of low-shrinking and conventional composites used as an orthodontic bracket bonding adhesive.
  
  
  METHODS
  A hundred twenty non-caries human premolars, extracted for orthodontic purposes, were used in this study. Sixty of them were separated into two groups. Brackets were bonded to the teeth in the test group with Silorane (3M-Espe) and control group with Transbond-XT (3M-Unitek). SBS values of these brackets were recorded in MPa using a universal testing machine. ARI scores were determined after the failure of brackets. The remaining 60 teeth were divided into two groups and microleakage was evaluated by the dye penetration method. Statistical analyses were performed by Wilcoxon, Pearson Chi-square, and Mann-Whitney U tests at P < 0.05 level.
  
  
  RESULTS
  The mean SBS for Transbond XT was significantly greater than low-shrinking composite (P < 0.001). Significant differences (χ(2) =29.60, P < 0.001) were present between the two groups for the ARI scores. Microleakage values were lower in low-shrinking composite than in the control group, and this difference was found to be statistically significant (P < 0.001).
  
  
  CONCLUSIONS
  Although low-shrinking composite produced insufficient SBS and ARI scores, microleakage values were lower in low-shrinking composite than in the control group on the etched enamel surfaces, when used as a bracket bonding composite.
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Suleyman Kutalmis
authors.initials: SK
authors.lastname: Buyuk
authors.affiliation: Department of Pediatric Dentistry, Faculty of Dentistry,Erciyes University, Kayseri, Turkey.
authors.forename: Kenan
authors.initials: K
authors.lastname: Cantekin
authors.affiliation: Department of Restorative Dentistry, Faculty of Dentistry, Erciyes University, Kayseri, Turkey.
authors.forename: Sezer
authors.initials: S
authors.lastname: Demirbuga
authors.affiliation: Department of Orthodontics, Faculty of Dentistry, Izmir Katip Celebi University, Izmir, Turkey.
authors.forename: Mehmet
authors.initials: M
authors.lastname: Ali Ozturk
keywords: Minimally shrinkage composite; orthodontics; shear bond; silorane