Effect of sodium ascorbate on bond strength and metalloproteinases activity in bleached dentin

This study evaluated the effect of sodium ascorbate (SA) on the proteolytic activity of matrix metalloproteinases (MMPs) and investigated the related effects on the bond strength of bleached dentin.

Eighty freshly extracted human third molars were randomly divided according to treatment (bleaching or SA application), type of analysis (microshear or measuring MMP activity), and post-bleaching time to assess bond strength (24 hrs or 30 days). Data from both analyses were subjected to one-way analysis of variance to detect differences among groups, followed by Tukey's multiple comparison test (p≤0.05).

Dental bleaching significantly reduced bond strength values when the adhesive strategy was performed after 24 hrs (despite the SA treatment) or 30 days after the bleaching procedure. However, after 30 days, the bond strength values of the groups who received bleaching or SA application were similar to those of the unbleached group. Dental bleaching caused the activation of MMPs, and SA did not influence this activity.

It was concluded that SA does not affect the activity of MMPs or the bond strength in bleached dentin immediately after the bleaching treatment.