Sodium p-Toluenesulfinate Enhances the Bonding Durability of Universal Adhesives on Deproteinized Eroded Dentin

The effects of deproteinization using sodium hypochlorite (NaOCl) and the subsequent application of an antioxidant (sodium p-toluenesulfinate, STS) onto the bonding durability of universal adhesives on eroded dentin were investigated. Untreated sound dentin served as the control, whereas eroded dentin, which had been prepared by pH-cycling in 1% citric acid and a remineralization solution, was either untreated, deproteinized with a 10% NaOCl gel or deproteinized with the 10% NaOCl gel and subsequently treated with an STS-containing agent. The dentin surfaces were bonded using a universal adhesive (Clearfil Universal Bond Quick, Scotchbond Universal or G-Premio Bond), and the micro-tensile bond strength (mu TBS) test was performed after 24 h or 10,000 thermal cycles. The mu TBS data were statistically analyzed using a three-way ANOVA and Tukey's HSD post hoc tests. The lowest mu TBS was measured on untreated eroded dentin (p < 0.001). Deproteinization of eroded dentin resulted in mu TBS similar to untreated sound dentin (p > 0.05), but the highest mu TBS was obtained if deproteinization was followed by the application of STS. Thermocycling significantly decreased mu TBS in all groups (p < 0.001), except for STS-treated deproteinized eroded dentin (p > 0.05). This indicated that deproteinization, followed by the application of STS, could enhance the bonding durability of universal adhesives on eroded dentin.

Automated summary

Deproteinization followed by antioxidant application enhanced the bonding durability of universal adhesives on eroded dentin, indicating the potential clinical relevance of this method for improving bond strength in dentin.