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 disks 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 speci mens were treated with a sulfinate agent (Scotchbond Universal Dual Cure Activator; SDA) prior to the application of a 1-SEA (Bond Force II [Tokuyama Dental] or Clearfil Universal Bond Quick [Kuraray Noritake]). 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 0.05 significance level. Results The 24-h μTBS of both adhesives increased statistically significantly with the HOCl pretreatment for 15s or 30 s (p< 0.05), but it was not statistically significantly affected by the application of SDA (p>0.05). However, after TC, the groups treated with the combination of HOCl and SDA maintained their μTBS (p>0.05), as opposed to un treated 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 statistically significantly affect the immediate bond strength of 1-SEAs, and it could not prevent a significant decrease in the bond strength to untreated dentin after thermocycling. How ever, the sulfinate agent significantly improved the bonding durability of 1-SEAs to HOCl smear-layer deproteinized dentin.