title: Enamel surface evaluation after bracket debonding and different resin removal methods.
abstract: OBJECTIVE
  To assess enamel surface under scanning electron microscopy (SEM) after resin removal and enamel polishing procedures following brackets debonding, as well as compare the time required for these procedures.
  
  
  METHODS
  A total of 180 deciduous bovine incisors were used. The enamel surface of each tooth was prepared and brackets were bonded with light cured Transbond XT composite resin. Brackets were removed in a testing machine. The samples were randomized and equally distributed into nine groups according to the resin removal and polishing technique: Group 1, 30-blade tungsten carbide bur in high speed; Group 2, 30-blade tungsten carbide bur in high speed followed by a sequence of 4 Sof-lex polishing discs (3M); Group 3, 30-blade tungsten carbide bur in high speed followed by Enhance tips (Dentsply). All groups were subdivided into (a) unpolished; (b) polished with aluminum oxide paste; and (c) polished with water slurry of fine pumice. Subsequently, the enamel surface was assessed and statistical analysis was carried out.
  
  
  RESULTS
  There were statistically significant differences in enamel roughness and removal time among all groups. Groups 3a, 3b and 3c appeared to be the most efficient methods of removing resin with low damages to enamel. Groups 2a, 2b and 2c were the most time consuming procedures, and Group 2a caused more damages to enamel.
  
  
  CONCLUSIONS
  The suggested protocol for resin removal is the 30-blade tungsten carbide bur in high speed followed by Enhance tips and polishing with aluminum oxide paste. This procedure seems to produce less damages and is less time consuming.
authors.affiliation: Universidade Federal do Rio Grande do Sul, Santa Cecília, Rio Grande do Sul, Brazil.
authors.forename: Michele Machado
authors.initials: MM
authors.lastname: Vidor
authors.affiliation: Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Rafael Perdomo
authors.initials: RP
authors.lastname: Felix
authors.affiliation: Department of Dentistry, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Ernani Menezes
authors.initials: EM
authors.lastname: Marchioro
authors.affiliation: School of Dentistry, São Leopoldo Mandic, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: Luciane
authors.initials: L
authors.lastname: Hahn
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000537:Aluminum Oxide / Q000737:chemistry; D000818:Animals; D002417:Cattle; D001840:Dental Bonding / Q000379:methods; D017005:Dental Debonding / Q000295:instrumentation / Q000379:methods*; D003743:Dental Enamel / Q000648:ultrastructure*; D003754:Dental High-Speed Equipment; D003777:Dental Prophylaxis / Q000295:instrumentation / Q000379:methods*; D008855:Microscopy, Electron, Scanning; D016910:Orthodontic Brackets; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D017640:Silicates / Q000737:chemistry; D013499:Surface Properties; D013997:Time Factors; D017973:Tungsten Compounds / Q000737:chemistry
chemical_list: D019279:Resin Cements; D017640:Silicates; C477790:Transbond XT; D017973:Tungsten Compounds; C002802:tungsten carbide; D000537:Aluminum Oxide; C005144:pumice