ABSTRACT Aim This study aimed to evaluate the effects of N‐acetylcysteine (NAC) supplementation in apical periodontitis (AP) induced in rats. Methodology Eighteen male Wistar rats were randomly assigned to three groups: control, AP, and AP plus NAC. NAC was administered by oral gavage (100 mg/kg/day), beginning 1 day after lesion induction and continued daily until the day preceding euthanasia. AP induction was performed by exposing the dental pulp of the lower first molars bilaterally, maintaining this condition for 28 days. After this period, the animals were euthanized, and the following biological materials were collected: blood (for systemic oxidative stress analysis) and hemimandibles for histopathological and histochemical, and micro‐computed tomography analyses, aiming to measure bone quality parameters and periapical volume. Statistical analyses were performed using one‐way ANOVA and Tukey's post hoc test. In addition, correlation analyses and multivariate analyses of variance (MANOVA) were performed on the biochemical parameters. Results The study results showed that animals supplemented with NAC had greater preservation of bone quality parameters and a reduction in periapical volume progression when compared to the only apical periodontitis group. Additionally, in the analysis of systemic oxidative stress, supplemented animals showed higher antioxidant parameter levels and lower oxidant levels compared to non‐supplemented animals, which also showed reduced preservation of bone collagen content. Conclusions The study findings suggest that NAC supplementation promoted greater preservation of bone quality, reduced periapical volume development, and modulation of endogenous antioxidant and oxidant aspects. This indicates that NAC can decrease local and systemic damage caused by AP, highlighting its potential as an adjunctive agent in processes involving systemic oxidative stress and the preservation of biological structures.
Santos et al. (Thu,) studied this question.