Aim To evaluate the effect of antioxidant pretreatment on the shear bond strength and failure modes of total-etch and self-etch adhesive systems applied to sodium hypochlorite (NaOCl)–treated dentin. Materials and methods Eighty extracted human premolars were prepared and irrigated with NaOCl. The specimens were allocated into two groups based on the adhesive strategy employed: total-etch and self-etch. Each group was further subdivided according to antioxidant pretreatment: control (no antioxidant), sodium ascorbate, alpha-tocopherol, and nanocurcumin. Composite resin was bonded, and shear bond strength was tested using a universal testing machine. Failure modes were evaluated microscopically. Data were analyzed using one-way ANOVA with post-hoc tests, two-way ANOVA to assess the effects of antioxidant type and adhesive system, and chi-square analysis for failure modes (P 0.05). Results NaOCl-treated dentin without antioxidant pretreatment showed the lowest bond strength values in both adhesive systems. Sodium ascorbate and nanocurcumin significantly improved bond strength compared with control and alpha-tocopherol, with no significant difference between them. Self-etch adhesives demonstrated lower baseline bond strength but greater recovery following antioxidant pretreatment. Two-way ANOVA revealed significant effects of antioxidant type, adhesive system, and their interaction. Control groups predominantly exhibited adhesive failures, while antioxidant-treated groups showed increased mixed and cohesive failures. Conclusion Antioxidant pretreatment effectively restores bonding to NaOCl-treated dentin. Sodium ascorbate and nanocurcumin demonstrated comparable efficacy, with greater benefit observed for self-etch adhesives.
Harish et al. (Wed,) studied this question.