title: Direct bonding to Adlloy-treated amalgam.
abstract: The purpose of this study was to test the bond-enhancing effect by modifying amalgam surfaces with Adlloy (a gallium-tin liquid alloy) and bonding brackets by using two different resin systems. Bond strength and location of bond failure was assessed by using (1) Concise (3M Dental Products) and (2) C&B Metabond (Parkell) systems with and without the use of Adlloy alloy. Class V buccal amalgam restorations (n = 132) were subjected to one of two surface treatments: (1) sandblasting or (2) sandblasting plus Adlloy treatment. Mandibular premolar brackets were bonded with Concise composite resin or C&B Metabond (adhesive) to amalgam surfaces. All specimens were stored in 37 degrees C water for 10 weeks and subjected to thermocycling before bond strength testing. The laboratory shear bond strength of Concise material to amalgam was not improved after Adlloy modification. However, Adlloy-treated amalgam significantly increased the laboratory shear bond strength of orthodontic brackets bonded with C&B Metabond material. The majority (58%) of the bond failures of C&B Metabond bonded to non-Adlloy treated-amalgam occurred at the amalgam-adhesive interface, whereas the majority (58%) of the bond failure of C&B Metabond bonded to Adlloy-treated amalgam failed within the adhesive. Fracture within the amalgam during debonding was observed with C&B Metabond bonded to sandblasted amalgam (21%) and Adlloy-treated amalgam (15%). Regardless of Adlloy treatment, C&B Metabond would appear to provide adequate orthodontic bonding to amalgam; however, there may exist a potential risk of amalgam restoration fracture upon debonding.
authors.affiliation: Division of Graduate Orthodontics, University of Western Ontario, London, Canada.
authors.forename: M W
authors.initials: MW
authors.lastname: Gross
authors.forename: T F
authors.initials: TF
authors.lastname: Foley
authors.forename: A H
authors.initials: AH
authors.lastname: Mamandras
mesh_terms: D001641:Bicuspid; D003722:Dental Alloys; D003723:Dental Amalgam; D001840:Dental Bonding / Q000379:methods* / Q000706:statistics & numerical data; D017005:Dental Debonding / Q000706:statistics & numerical data; D003775:Dental Polishing / Q000379:methods; D004868:Equipment Failure / Q000706:statistics & numerical data; D005708:Gallium; D006801:Humans; D066298:In Vitro Techniques; D008422:Materials Testing / Q000379:methods / Q000706:statistics & numerical data; D016910:Orthodontic Brackets / Q000706:statistics & numerical data; D013499:Surface Properties; D014001:Tin
chemical_list: C075320:Adlloy; D003722:Dental Alloys; D014001:Tin; D003723:Dental Amalgam; D005708:Gallium