Effect of scaling and root planing on the expression of neuregulin‑4 levels and its receptor ErbB4 in GCF in patients with stage III periodontitis with and without type 2 diabetes mellitus: An interventional comparative study

The present study evaluated and associated the effects of scaling and root planing (SRP) on gingival crevicular fluid (GCF) levels of neuregulin‑4 (NRG4) and its receptor ErbB4 in patients with stage III periodontitis, with and without type 2 diabetes mellitus (T2DM). A total of 45 subjects were divided into three groups, as follows: Periodontally healthy individuals, patients with stage III periodontitis and patients with stage III periodontitis with well‑controlled T2DM. Clinical parameters, including gingival index, plaque index, bleeding on probing, probing pocket depth and clinical attachment level, were recorded at baseline and 3 months following non‑surgical periodontal therapy (NSPT). GCF samples were collected from the deepest periodontal site 24‑72 h following SRP at baseline and at 3 months post‑therapy, and analyzed for NRG4 and ErbB4 levels using enzyme‑linked immunosorbent assay. At baseline, the GCF levels of NRG4 and ErbB4 were significantly higher in patients with periodontitis compared to healthy individuals, with the highest levels observed in patients with T2DM. Following NSPT, all clinical parameters exhibited a significant improvement, accompanied by a statistically significant reduction in biomarker levels at 3 months. Significant positive correlations were observed between the GCF NRG4 and ErbB4 levels and periodontal clinical parameters at baseline in groups 2 and 3. These findings indicated that GCF NRG4 and ErbB4 levels were associated with periodontal clinical parameters in this cohort and changed following NSPT. However, their independent clinical utility as biomarkers of disease activity or treatment response cannot be established from the present study. Further larger, longitudinal, and mechanistic studies are required to validate their clinical significance.