Effect of adjunctive use of systemic antioxidant therapy (N-acetylcysteine) on soluble receptor activator nuclear factor κB ligand levels in gingival crevicular fluid following surgical periodontal treatment for chronic periodontitis.

N-acetylcysteine (NAC) is an anti-oxidant drug that has been used as a mucolytic agent and a paracetamol antidote for many years. This study was designed to determine the efficacy of the adjunctive use of NAC for periodontal treatment. Thirty subjects with moderate-to-severe chronic periodontitis were randomized to surgery with NAC (600 mg; S-NAC), surgery only (S-nonNAC), and healthy control groups. Gingival crevicular fluid (GCF) samples were obtained from all patients and sRANKL levels were determined by enzyme-linked immunosorbent assay at baseline, and 1, 3, and 7 months post-surgery. Plaque and gingival indices, probing depths, and clinical attachment levels were recorded at the same time. There was a significant reduction in probing depth at 3 months in the S-NAC group when compared to the S-nonNAC group (P < 0.05). However, no statistically significant differences in plaque and gingival indices, probing depths, clinical attachment levels, and sRANKL levels in GCF were noted between the surgical treatment groups at the end of 7 months. Hence, the use of adjunctive NAC resulted in a significant reduction in probing depths in the S-NAC group when compared to the S-nonNAC group at 3 months, but no statistically significant differences in GCF sRANKL levels were observed in the sites that underwent surgical treatment with or without NAC at different time intervals.