title: The effect of bonded resin surface area on the detachment force of lingual bonded fixed retainers: An in vitro study.
abstract: OBJECTIVE
  The aims of this study were to evaluate the relationship between the detachment force and bonding resin surface are and to determine the resin bonding surface area that would provide adequate bonding strength with minimum resin volume.
  
  
  METHODS
  One hundred and sixty human premolars were randomly divided into 4 groups of 40 teeth each. The diameter of the resin surface area in each group was as follows: group 1, 1.5 mm; group 2, 2.5 mm; group 3, 3.5 mm; and group 4, 4.5 mm. Respond Dead Soft straight (length 0.0175 inch) was used to fabricate the retainers, and Transbond™ XT was used to fix the retainers to the tooth surfaces. A pair of teeth was embedded in acrylic blocks for each specimen. Thus, each group comprised 20 samples. Fixed retainers were bonded to the teeth, and vertical force was applied at the middle of wire. The force was measured using a universal testing machine.
  
  
  RESULTS
  The mean value of detachment force was the highest for group 4 (102.38 ± 2.92 N), followed by group 3 (63.54 ± 2.21 N), group 2 (51.95 ± 1.61 N), and group 1 (24.14 ± 1.38 N).
  
  
  CONCLUSIONS
  The detachment force of lingual fixed retainers was significantly affected as the area of the resin bonding surface increased. Considering the minimum bonding strength of brackets, a resin bonding surface area with a diameter of 3.5 mm would provide adequate bonding strength.
authors: Department of Orthodontics, Hallym University Sacred Heart Hospital, Hallym University Medical Center, Anyang, Korea.
authors: Il-Hong
authors: IH
authors: Lee
authors: Department and Research Institute of Dental Biomaterials and Bioengineering, College of Dentistry, Yonsei University, Seoul, Korea.
authors: Jung-Hwan
authors: JH
authors: Lee
authors: Department of Orthodontics, Hallym University Sacred Heart Hospital, Hallym University Medical Center, Anyang, Korea.
authors: In-Young
authors: IY
authors: Park
authors: Department of Orthodontics, Hallym University Sacred Heart Hospital, Hallym University Medical Center, Anyang, Korea.
authors: Ji-Hyun
authors: JH
authors: Kim
authors: Department of Orthodontics, Hallym University Kangnam Sacred Heart Hospital, Hallym University Medical Center, Seoul, Korea.
authors: Jang-Hoon
authors: JH
authors: Ahn
keywords: Bonding strength; Lingual fixed retainer; Surface area