title: Laser-aided debonding of orthodontic ceramic brackets.
abstract: The removal of ceramic brackets from the enamel surface by means of laser heating was investigated with the use of CO2 and YAG lasers. The two bracket types investigated were polycrystalline alumina and monocrystalline alumina. The average torque force necessary to break the adhesive between the polycrystalline ceramic brackets and the tooth was lowered by a factor of 25 when the brackets were illuminated with a CO2 laser beam of 14 watts for 2 seconds. All polycrystalline brackets debonded with the CO2 laser resulted in a complete bracket detachment without bracket failure. The average torque force needed to debond monocrystalline brackets was lowered by a factor of 5.2 when illuminated with a laser setting of 7 watts. Monocrystalline brackets cracked along the bracket slot in 2 of 10 cases. Debracketing without laser heating resulted in a slightly higher incidence of bracket failure (12 of 50). Nevertheless, no visible damage to the enamel surface was observed. Advantages of the laser-aided bracket-removal techniques include the following: The heat produced is localized and controlled; the debracketing tool is essentially "cold"; and the method can be used for removal of various types of ceramic brackets, regardless of their design.
authors.affiliation: Los Alamos National Laboratory, N.M.
authors.forename: K
authors.initials: K
authors.lastname: Strobl
authors.forename: T L
authors.initials: TL
authors.lastname: Bahns
authors.forename: L
authors.initials: L
authors.lastname: Willham
authors.forename: S E
authors.initials: SE
authors.lastname: Bishara
authors.forename: W C
authors.initials: WC
authors.lastname: Stwalley
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D000538:Aluminum Silicates; D017438:Bisphenol A-Glycidyl Methacrylate; D002245:Carbon Dioxide; D002516:Ceramics / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods; D017005:Dental Debonding / Q000379:methods*; D003743:Dental Enamel; D004868:Equipment Failure; D006358:Hot Temperature; D006801:Humans; D007834:Lasers; D009354:Neodymium; D016910:Orthodontic Brackets; D013314:Stress, Mechanical; D013814:Thermal Conductivity; D013997:Time Factors; D015019:Yttrium
chemical_list: D000180:Acrylic Resins; D000538:Aluminum Silicates; D003188:Composite Resins; D002245:Carbon Dioxide; D009354:Neodymium; D017438:Bisphenol A-Glycidyl Methacrylate; D015019:Yttrium; D000537:Aluminum Oxide