title: The effect of amalgam surface preparation on the shear bond strength between composite and amalgam.
abstract: The aim of this study was to investigate the effect of amalgam surface preparation on the short-and long-term in vitro shear bond strength between a dental amalgam (Valiant) and two dental composites (Herculite, Z100) mediated by three universal bonding agents (All-Bond 2, Amalgambond, and Scotchbond Multi-Purpose). Cylinders of dental composite resin were formed on, and bonded to flat amalgam surfaces. Prior to bonding, the amalgam surfaces were: a) ground flat, with the grinding lines oriented parallel to the direction of the shear stress; b) ground flat, with the grinding lines oriented perpendicular to the direction of the shear stress; or c) ground flat and then sandblasted using 50 micrometer Al2O3. A computerized Universal Testing Machine was used to determine the 1-, 7-, and 30-day shear bond strength of 162 samples (six per group) that were stored in distilled water at 37 degrees C. The results, which were statistically analyzed by performing a three-way analysis of variance (ANOVA) and 27 one-way ANOVA followed by modified (Bonferroni) t-tests for between-group comparisons (alpha = 0.05), have shown that: 1) sandblasting resulted in higher shear bond strength than grinding, except for 1-day All-Bond 2, where no differences were identified; 2) there was no difference in the shear bond strength between samples with parallel or perpendicular ground surfaces for a given bonding system and storage time; 3) for All-Bond 2, the 7-day shear bond strength of parallel and perpendicular ground samples dropped to half of the 1-day values, while the sandblasted samples showed a constant, high shear bond strength over 30 days, 4) for Amalgambond, the shear bond strength of parallel, perpendicular, and sand blasted samples was constant over 30 days; and 5) for Scotchbond Multi-Purpose, a sharp drop in the 7-day shear bond strength was recorded for all the samples, irrespective of amalgam surface preparation.
authors.affiliation: Department of Oral Biology, Faculty of Dentistry, The University of British Columbia, Vancouver, Canada.
authors.forename: N D
authors.initials: ND
authors.lastname: Ruse
authors.forename: R T
authors.initials: RT
authors.lastname: Sekimoto
authors.forename: D
authors.initials: D
authors.lastname: Feduik
mesh_terms: D003188:Composite Resins; D003722:Dental Alloys / Q000737:chemistry*; D003723:Dental Amalgam / Q000737:chemistry; D001840:Dental Bonding / Q000379:methods; D003775:Dental Polishing / Q000379:methods*; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; D012822:Silicon Dioxide; D015040:Zirconium
chemical_list: C074864:All-Bond system; C070606:Amalgambond; D003188:Composite Resins; D003722:Dental Alloys; D017220:Dentin-Bonding Agents; D008689:Methacrylates; D019279:Resin Cements; C084018:Scotchbond Multi-Purpose; C083568:Z100 composite resin; C065770:Herculite XR; D012822:Silicon Dioxide; D003723:Dental Amalgam; C072894:Valiant PhD; D015040:Zirconium