Tips and Tricks for Dentin Bonding with Universal Adhesive 1)-light-polymerization

Objectives: The aim of this study was to evaluate the effect of light-polymerization on dentin shear bond strength of universal adhesives.
Methods: Dentin specimens were polished with 320-grit SiC paper and rinsed. Dentin specimens were treated with a universal adhesive (All-Bond Universal, Bisco; or Scotchbond Universal, 3M) or a control dual-cure adhesive (Universal Primer, Bisco). The adhesive was air dried, and then was either light-polymerized (10 sec at 500mw/cm²) or not polymerized. Shear bond strength was tested using the notched-edge shear bond strength test method (ISO 29022:2013). Resin cement (Duolink, used with All-Bond Universal and Universal Primer, Bisco; or amine-free RelyX Ultimate Cement, used with Scotchbond Universal, 3M) was placed on the dentin surface and polymerized (either light-polymerized for 40sec at 500mw/cm², or self-polymerized for 15 min/37 °C). The specimens were then stored in water at 37°C for 24 hours and tested by universal testing machine (Instron, crosshead-speed 1mm/min). The data were analyzed statistically by one-way ANOVA and Student-t Test.
Results: Mean shear bond strengths (n=5) in MPa (standard deviation) are shown in Table 1. Means with different letters in the same column are statistically different (p<0.05).
Conclusions: Dentin bond strength was substantially lowered if adhesives were not light-polymerized before cementation. Without light-polymerization of adhesives, the dentin bond strengths of light-cure adhesives were not clinically acceptable, while the bond strength of dual-cure adhesive was clinically acceptable.