IADR Abstract Archives
Shear Bond Strength of Universal Adhesives – Varying Application Steps
Objectives: To measure shear bond strength of a universal adhesive applied to enamel and dentin when application procedures varied from manufacturer’s IFU.
Methods: 100 extracted human teeth were wet ground to expose a flat bonding surface. In 20, superficial enamel and in 80, medium deep dentin was exposed by grinding with a 320-grit SiC paper to establish a standardized surface. In control groups, the adhesive was applied following manufacturer’s IFU. The experimental groups were applied following manufacturer’s IFU except as noted (Table 1). All specimens were light polymerized with Blue Phase curing light (Ivoclar, output=1300mW/cm2) less than 3mm from the tooth surface for time specified by IFU or as listed in Table 1. After the adhesive was applied, a Teflon tube (ID=1.5 mm) filled with uncured Clearfil Majesty ES2 composite was applied over the bonded tooth surface and light cured from the occlusal and each side (5 cures total), 10 seconds each cure. After incubator storage (24h/37°C) in deionized water, the specimens were placed in a fixture for bond strength testing using a horseshoe-shaped blade and subjected to shear loading to failure using a universal testing machine at a crosshead speed of 1mm/min. The peak failure load and surface area of the plastic tube were used to calculate shear bond strength. Data were analyzed using a 2-way ANOVA and Tukey HSD post-hoc test.
Results: See table.
Conclusions: Universal adhesives are robust and can tolerate many clinical shortcomings.
Methods: 100 extracted human teeth were wet ground to expose a flat bonding surface. In 20, superficial enamel and in 80, medium deep dentin was exposed by grinding with a 320-grit SiC paper to establish a standardized surface. In control groups, the adhesive was applied following manufacturer’s IFU. The experimental groups were applied following manufacturer’s IFU except as noted (Table 1). All specimens were light polymerized with Blue Phase curing light (Ivoclar, output=1300mW/cm2) less than 3mm from the tooth surface for time specified by IFU or as listed in Table 1. After the adhesive was applied, a Teflon tube (ID=1.5 mm) filled with uncured Clearfil Majesty ES2 composite was applied over the bonded tooth surface and light cured from the occlusal and each side (5 cures total), 10 seconds each cure. After incubator storage (24h/37°C) in deionized water, the specimens were placed in a fixture for bond strength testing using a horseshoe-shaped blade and subjected to shear loading to failure using a universal testing machine at a crosshead speed of 1mm/min. The peak failure load and surface area of the plastic tube were used to calculate shear bond strength. Data were analyzed using a 2-way ANOVA and Tukey HSD post-hoc test.
Results: See table.
Conclusions: Universal adhesives are robust and can tolerate many clinical shortcomings.