title: Effect of a low-viscosity adhesive resin on the adhesion of metal brackets to enamel etched with hydrochloric or phosphoric acid combined with conventional adhesives.
abstract: OBJECTIVE
  This study investigated the effect of a low-viscosity adhesive resin (Icon) applied after either hydrochloric (HCl) or phosphoric acid (H3PO4) on the adhesion of metal brackets to enamel. Failure types were analyzed.
  
  
  METHODS
  The crowns of bovine incisors (N = 20) were sectioned mesio-distally and inciso-gingivally, then randomly assigned to 4 groups according to the following protocols to receive mandibular incisor brackets: 1) H3PO4 (37%)+TransbondXT (3M UNITEK); 2) H3PO4 (37%)+Icon+TransbondXT; 3) HCl (15%)+Icon (DMG)+TransbondXT 4) HCl (15%)+Icon+Heliobond (Ivoclar Vivadent)+TransbondXT. Specimens were stored in distilled water at 37°C for 24 h and thermocycled (5000x, 5°C to 55°C). The shear bond strength (SBS) test was performed using a universal testing machine (1 mm/min). Failure types were classified according to the Adhesive Remnant Index (ARI). Contact angles of adhesive resins were measured (n = 5 per adhesive) on ceramic surfaces.
  
  
  RESULTS
  No significant difference in SBS was observed, implying no difference between combinations of adhesive resins and etching agents (p = 0.712; ANOVA). The Weibull distribution presented significantly lower Weibull modulus (m) of group 3 (m = 2.97) compared to other groups (m = 5.2 to 6.6) (p < 0.05). The mean SBS results (MPa) in descending order were as follows: group 4 (46.7 ± 10.3) > group 1 (45.4 ± 7.9) > group 2 (44.2 ± 10.6) > group 3 (42.6 ± 15.5). While in groups 1, 3, and 4 exclusively an ARI score of 0 (no adhesive left on tooth) was observed, in group 2, only one specimen demonstrated score 1 (less than half of adhesive left on tooth). Contact angle measurements were as follows: Icon (25.86 ± 3.81 degrees), Heliobond (31.98 ± 3.17 degrees), TransbondXT (35 ± 2.21 degrees).
  
  
  CONCLUSIONS
  Icon can be safely used with the conventional adhesives tested on surfaces etched with either HCl or H3PO4.
authors.forename: Enver
authors.initials: E
authors.lastname: Yetkiner
authors.forename: Mutlu
authors.initials: M
authors.lastname: Ozcan
authors.forename: Florian Just
authors.initials: FJ
authors.lastname: Wegehaupt
authors.forename: Annette
authors.initials: A
authors.lastname: Wiegand
authors.forename: Ece
authors.initials: E
authors.lastname: Eden
authors.forename: Thomas
authors.initials: T
authors.lastname: Attin
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods*; D000179:Acrylates / Q000737:chemistry; D000180:Acrylic Resins / Q000737:chemistry; D000268:Adhesiveness; D000818:Animals; D002417:Cattle; D001840:Dental Bonding; D003743:Dental Enamel / Q000648:ultrastructure*; D003799:Dental Stress Analysis / Q000295:instrumentation; D006851:Hydrochloric Acid / Q000737:chemistry*; D008689:Methacrylates / Q000737:chemistry; D016910:Orthodontic Brackets; D010756:Phosphoric Acids / Q000737:chemistry*; D011897:Random Allocation; D019279:Resin Cements / Q000737:chemistry*; D012117:Resins, Synthetic / Q000737:chemistry; D033081:Shear Strength; D013314:Stress, Mechanical; D013696:Temperature; D013997:Time Factors; D014783:Viscosity; D014867:Water / Q000737:chemistry; D017155:Wettability
chemical_list: D000179:Acrylates; D000180:Acrylic Resins; D008689:Methacrylates; D010756:Phosphoric Acids; D019279:Resin Cements; D012117:Resins, Synthetic; C477790:Transbond XT; C578177:icon infiltrant; D014867:Water; C040415:heliobond; C030242:phosphoric acid; D006851:Hydrochloric Acid