Application of Sulfinate Agent in Conjunction with HOCl Smear-Layer Deproteinization Improves Dentin Bonding Durability of One-step Self-etch Adhesives
Abstract
Purpose: To evaluate the effect of a sulfinate agent on the bonding durability of one-step self-etch adhesives (1-SEAs) to smear layer-covered dentin deproteinized with hypochlorous acid (HOCl). Materials and Methods: Human coronal dentin discs with a standardized smear layer were deproteinized with 100 ppm HOCl solution for 0 s (control), 15 s or 30 s.
After rinsing with water for 30 s and air-drying, half of the specimens were treated with a sulfinate agent (Scotchbond Universal Dual Cure Activator; SDA) prior to the application of a 1-SEA (Bond Force II or Clearfil Universal Bond Quick). Microtensile bond strength (μTBS) was measured after 24 h or 10,000 thermal cycles (TC).
The data were analyzed by three-way ANOVA with Tukey's post hoc tests and t-tests at the significance level of 0.05. Results: The 24 h μTBS of both adhesives increased significantly with the HOCl pretreatment for 15 s or 30 s (p0.05).
However, after TC, the groups treated with the combination of HOCl and SDA maintained their μTBS (p>0.05), as opposed to untreated dentin and dentin treated with either HOCl or SDA whose μTBS decreased significantly (p<0.05). Conclusion: The application of the sulfinate agent did not significantly affect the immediate bonding of 1-SEAs, and it could not prevent a significant decrease in the bond strength to untreated dentin after thermocycling.
However, the sulfinate agent significantly improved the bonding durability of 1-SEAs to HOCl-smear layer deproteinized dentin.