Shear Bond Strength of Aged Dental Amalgam Repaired with Composite

Abstract

ObjectivesThe objective of this study was to evaluate the effect of surface treatment and adhesive agent on the shear bond strength between a resin composite and an aged dental amalgam (356-days). Materials and MethodsSixty amalgam (Tytin) disks were stored in water at 37°C for 365 days. Half of the specimens were airborne particle abraded and the remaining half was roughened with a greenstone. Resin composite cylinders (Tetric) were bonded onto the amalgam surfaces using Amalgambond, All-Bond 2 or Scotchbond 1 (n=10). Specimens were stored in water at 37°C for 7 days and thermocycled. Shear bond strength testing was carried on an Instron Universal Testing Machine. Stereomicroscope examination was carried out to determine the bond failure sites. Results were analyzed by ANOVA followed by Student-Newman-Keuls’ post-hoc tests and the level of statistical significance was set at 5%. ResultsSurface treatment significantly affected the shear bond strengths (p<0.001) with airborne particle abrasion producing the highest bond strengths. Significantly higher shear bond strengths (p=0.047) were found with Scotchbond 1 in comparison with All-Bond 2, in the airborne particle abraded specimens. Bond failures were predominantly of the adhesive type. ConclusionsAirborne particle abrasion resulted in a twofold increase in shear bond strength compared with roughening with a greenstone. Significant differences were found between the adhesives, in the airborne particle abraded specimens.