title: Immediate and Delayed Effects of Diode Laser on Debonding of Ceramic Brackets: An in vitro Study.
abstract: OBJECTIVE
  The aim of the study is to evaluate the immediate and delayed effects of diode laser on debonding of ceramic brackets.
  
  
  METHODS
  A total of 60 human extracted premolar teeth were randomly assigned to three different treatment groups. All teeth were bonded with adhesive precoated (APC) ceramic brackets (3M Unitek). A total of 20 teeth were debonded without lasing (group 1), 20 immediately after lasing (group 2), and 20 1 hour after lasing (group 3). For the lasing groups (groups 2 and 3), access cavity was prepared on the occlusal surface to a 2 mm diameter. A transbond plus self-etching primer (3M Unitek, Monrovia, CA, USA) and APC PLUS clarity advanced brackets (3M, Unitek, Monrovia, CA, USA) were used. The shear bond strength (SBS) and adhesive remnant index (ARI) were measured. The internal pulpal wall temperature was noted for the laser groups.
  
  
  RESULTS
  The mean SBS was 15.4, 11.57, and 11.79 MPa for groups 1 to 3 respectively. Post hoc test showed significant difference (p < 0.001) between the control group and the lased groups. For groups 2 and 3, the rise in temperature was at an average of 1.4 and 1.3°C respectively.
  
  
  CONCLUSIONS
  The SBS of APC brackets decreased by 33.3% on application of diode laser without increasing the internal pulp chamber wall temperature significantly. Shear bond strength remains more or less the same whether debonding is done immediately after lasing or 1 hour after lasing. Diode lasers increased the ARI scores and thus decreased the risk of enamel fracture.
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Praveena
authors.initials: P
authors.lastname: Anand
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: P B
authors.initials: PB
authors.lastname: Anand
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Ramachandran
authors.initials: R
authors.lastname: Prabhakar
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: N
authors.initials: N
authors.lastname: Rajvikram
authors.affiliation: Reader, Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India, Phone: +919444466148, e-mail: rajscare@hotmail.com.
authors.forename: P
authors.initials: P
authors.lastname: Rajakumar
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: Varun Reddy
authors.initials: VR
authors.lastname: Atali
authors.affiliation: Department of Orthodontics, Thai Moogambigai Dental College and Hospital, Chennai, Tamil Nadu, India.
authors.forename: R
authors.initials: R
authors.lastname: Saravanan
mesh_terms: D001641:Bicuspid; D002516:Ceramics; D017005:Dental Debonding; D006801:Humans; D066298:In Vitro Techniques; D054023:Lasers, Semiconductor; D008855:Microscopy, Electron, Scanning
keywords: Adhesive precoated brackets; Diode laser; Instron machine; Scanning electron microscope; Self-etching primer; Stereomicroscope.