Effect of scaling and root planing on the expression of anti-inflammatory cytokines (IL-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid of electronic cigarette users and non-smokers with moderate chronic periodontitis

PURPOSE: The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and non-smokers with moderate chronic periodontitis (CP). METHODS: Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P<0.05 was considered to indicate statistical significance. RESULTS: Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and non-smokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups (P<0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers (P<0.05) than in electronic cigarette users at the 3-month follow-up. CONCLUSIONS: Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.