Improving orthodontic bonding to gold alloy.
Flat tabs of cast gold alloy (n = 156) were subjected to either of three surface treatments: (1) roughening with diamond bur, (2) aluminum oxide sandblasting, and (3) sandblasting plus tin electroplating. Mandibular incisor edgewise brackets were bonded with Concise (BIS-GMA resin) (Unitek, Monrovia, Calif.) or Superbond C&B (4-META metal bonding resin) (Sun Medical Co. Ltd., Kyoto, Japan), or with Concise after application of an intermediate resin. All-Bond 2 Primers A and B (Bisco Dental Products, Itasca, Ill.), or B alone. All specimens were stored in water at 37 degrees C for 24 hours, and 60 were then thermocycled 1,000 times from 5 degrees C to 55 degrees C and back. The tensile bond strength testing was performed in a Lloyd 1,000R machine (Fareham, Hants, England). Alignment and uniform loading during testing were secured by engaging a hook in a circular ring soldered onto the bracket slot before bonding. Similar control brackets (n = 24) were bonded with Concise to extracted human premolars and lower incisors according to a routine procedure. Bond failure sites were classified by a modified ARI system. The results showed that sandblasting produced significantly stronger bonds to gold alloy than roughening with diamond bur. Superbond C&B provided significantly stronger bonds to gold alloy than Concise. There were generally insignificant differences in bond strengths between the water stored and the thermocycled specimens. Bond failures of Concise to sandblasted plus tin-plated gold alloy invariably occurred at the gold/adhesive interface, whereas those of Superbond C&B occurred within the adhesive or in the adhesive/bracket interface.(ABSTRACT TRUNCATED AT 250 WORDS)
D000704:Analysis of Variance; D017438:Bisphenol A-Glycidyl Methacrylate; D001896:Boron Compounds; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements; D003775:Dental Polishing / Q000379:methods; D004595:Electroplating; D006047:Gold Alloys; D006801:Humans; D008422:Materials Testing; D008689:Methacrylates; D008768:Methylmethacrylates; D016910:Orthodontic Brackets; D018709:Statistics, Nonparametric; D013499:Surface Properties; D013718:Tensile Strength; D014001:Tin
D001896:Boron Compounds; D003738:Dental Cements; D006047:Gold Alloys; D008689:Methacrylates; D008768:Methylmethacrylates; D017438:Bisphenol A-Glycidyl Methacrylate; D014001:Tin; C049495:Super-bond