title: [Bond strengths of customized titanium brackets manufactured by selective laser melting].
abstract: OBJECTIVE
  To investigate the bond strengths of customized titanium bracket manufactured by selective laser melting.
  
  
  METHODS
  Eighty human premolars which had been extracted for orthodontic purpose were collected and divided randomly (by random table) into two groups (customized bracket group and 3M bracket group, 40 molars in each group). The 35% phosphoric acid was used for etching and the brackets were bonded with 3M Unitek bonding adhesive. All bonded specimens were placed in saline for 24 hours at room temperature and were tested on DWD3050 electronic testing machine to determine the shear bond strength and tensile bond strength. After debonding, the adhesive remnant indexes (ARI) were recorded.
  
  
  RESULTS
  The shear bond strengths of customized brackets was 6.80 (6.20, 8.32) MPa, which was significantly lower than that of the 3M brackets [10.46 (9.72, 11.48) MPa] (Z = -3.463, P < 0.05). And the tensile bond strengths of customized brackets was (6.93 ± 1.21) MPa, which was significantly higher than that of the 3M brackets [(5.88 ± 1.23) MPa] (t = 2.81, P < 0.05). No significant difference was found in the ARI between two different kinds of the brackets.
  
  
  CONCLUSIONS
  The shear bond strength and tensile bond strength of both kinds of brackets were enough for clinic application.
authors.affiliation: Department of Orthodontics, Capital Medical University School of Stomatology, Beijing 100050, China.
authors.forename: Dao-xing
authors.initials: DX
authors.lastname: Zou
authors.forename: Ze-min
authors.initials: ZM
authors.lastname: Wang
authors.forename: Hong-ming
authors.initials: HM
authors.lastname: Guo
authors.forename: Song
authors.initials: S
authors.lastname: Li
authors.forename: Yu-xing
authors.initials: YX
authors.lastname: Bai
mesh_terms: D000134:Acid Etching, Dental; D000293:Adolescent; D001641:Bicuspid; D002648:Child; D003188:Composite Resins / Q000737:chemistry*; D001840:Dental Bonding / Q000379:methods*; D017005:Dental Debonding; D017220:Dentin-Bonding Agents / Q000737:chemistry; D006801:Humans; D007834:Lasers; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry; D011897:Random Allocation; D033081:Shear Strength; D013718:Tensile Strength; D014025:Titanium
chemical_list: C114659:3M Single Bond Dental Adhesive; D003188:Composite Resins; D017220:Dentin-Bonding Agents; D010756:Phosphoric Acids; D014025:Titanium; C030242:phosphoric acid