title: Influence of erbium, chromium-doped: Yttrium scandium-gallium-garnet laser etching and traditional etching systems on depth of resin penetration in enamel: A confocal laser scanning electron microscope study.
abstract: OBJECTIVE
  This study was performed to assess the resin tag length penetration in enamel surface after bonding of brackets to identify which system was most efficient.
  
  
  METHODS
  Our study was based on a more robust confocal microscopy for visualizing the resin tags in enamel. Totally, 100 extracted human first and second premolars have been selected for this study and were randomly divided into ten groups of 10 teeth each. In Group 1, the buccal enamel surface was etched with 37% phosphoric acid (3M ESPE), Group 2 with 37% phosphoric (Ultradent). In Groups 5, 6, and 7, erbium, chromium-doped: Yttrium scandium-gallium-garnet (Er, Cr: YSGG) laser (Biolase) was used for etching the using following specifications: Group 5 (1.5 W/20 Hz, 15 s), Group 6 (2 W/10 Hz, 15 s), and Group 7 (2 W/20 Hz, 15 s). In Groups 8, 9, and 10, Er, Cr: YSGG laser (Biolase) using same specifications and additional to this step, conventional etching on the buccal enamel surface was etched with 37% (3M ESPE) after laser etching. In Groups 1, 5, 6, 7, 8, 9, and 10 3M Unitek Transbond XT primer was mixed with Rhodamine B dye (Sigma-Aldrich, Germany) to etched surface and then cured for 20 s. In Group 2, Ultradents bonding agent was mixed with Rhodamine B. In Group 3, 3M Unitek Transbond PLUS, Monrovia, USA, which was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Group 4, with self-etching primer (Ultradent-Peak SE, USA) was mixed with Rhodamine B dye (Sigma-Aldrich, Germany). Later (3M Unitek, Transbond XT, Monrovia USA) [Figure 1] was used to bond the modified Begg brackets (T. P. Orthodontics) in Groups 1, 3, 5, 6, 7, 8, 9, and 10. In Groups 2, 4 Ultradent-Peak LC Bond was used to bond the modified brackets. After curing brackets were debonded, and enamel depth penetration was assessed using confocal laser scanning microscope.
  
  
  RESULTS
  Group J had a mean maximum depth of penetration of 100.876 μm, and Group D was the least having a maximum value of 44.254 μm.
  
  
  CONCLUSIONS
  Laser alone groups had comparable depths of penetration to that of self-etching groups but much lower than conventional acid etched groups.
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, Kannur Dental College, Kannur, India.
authors.forename: Vishal
authors.initials: V
authors.lastname: Vijayan
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, Rajah Muthiah Dental College and Hospital, Annamalai University, Chidambaram, Tamil Nadu, India.
authors.forename: K
authors.initials: K
authors.lastname: Rajasigamani
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, Rajah Muthiah Dental College and Hospital, Annamalai University, Chidambaram, Tamil Nadu, India.
authors.forename: K
authors.initials: K
authors.lastname: Karthik
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, Kannur Dental College, Kannur, India.
authors.forename: Sasidharan
authors.initials: S
authors.lastname: Maroli
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, Kannur Dental College, Kannur, India.
authors.forename: Jitesh
authors.initials: J
authors.lastname: Chakkarayan
authors.affiliation: Department of Orthodontics and Dentofacial Orthopaedics, P. S. M College of Dental Science and Research, Thrissur, Kerala, India.
authors.forename: Mohamed
authors.initials: M
authors.lastname: Haris
keywords: Acid etching; bonding; chromium-doped: Yttrium scandium-gallium-garnet laser; confocal laser scanning microscope; enamel etching; erbium; lasers; self-etching primers