title: The use of easily debondable orthodontic adhesives with ceramic brackets.
abstract: We experimentally produced an easily debondable orthodontic adhesive (EDA) containing heat-expandable microcapsules. The purpose of this in vitro study was to evaluate the best debondable condition when EDA was used for ceramic brackets. Shear bond strengths were measured before and after heating and were compared statistically. Temperatures of the bracket base and pulp wall were also examined during heating. Bond strengths of EDA containing 30 wt% and 40 wt% heat-expandable microcapsules were 13.4 and 12.9 MPa, respectively and decreased significantly to 3.8 and 3.7 MPa, respectively, after heating. The temperature of the pulp wall increased 1.8-3.6°C after heating, less than that required to induce pulp damage. Based on the results, we conclude that heating for 8 s during debonding of ceramic brackets bonded using EDA containing 40 wt% heat-expandable microcapsules is the most effective and safest method for the enamel and pulp.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry, 1-8-13 Kandasurugadai, Chiyoda-ku, Tokyo 101-8310, Japan.
authors.forename: Chiyako
authors.initials: C
authors.lastname: Ryu
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Namura
authors.forename: Takashi
authors.initials: T
authors.lastname: Tsuruoka
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Hama
authors.forename: Kaori
authors.initials: K
authors.lastname: Kaji
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D001831:Body Temperature / Q000502:physiology; D001896:Boron Compounds / Q000737:chemistry; D002214:Capsules; D002417:Cattle; D002516:Ceramics / Q000737:chemistry*; D001840:Dental Bonding; D017005:Dental Debonding / Q000379:methods*; D003764:Dental Materials / Q000737:chemistry*; D003782:Dental Pulp / Q000502:physiology; D003799:Dental Stress Analysis / Q000295:instrumentation; D006358:Hot Temperature; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry; D008768:Methylmethacrylates / Q000737:chemistry; D016910:Orthodontic Brackets; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D033081:Shear Strength; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013821:Thermometers; D013997:Time Factors
chemical_list: D001896:Boron Compounds; D002214:Capsules; D003764:Dental Materials; D008689:Methacrylates; D008768:Methylmethacrylates; D019279:Resin Cements; D013193:Stainless Steel; C049495:Super-bond