{
  "abstract": "This study evaluated Growth differentiation factor-15 (GDF-15), SMAD2, SMAD5, SMAD6 and Interleukin-6 (IL-6) levels in gingival crevicular fluid (GCF) and saliva in periodontitis and periodontal health, and assessed relationships with clinical periodontal parameters. Forty-four systemically healthy individuals were enrolled, including 22 patients with Stage III/Grade B periodontitis and 22 periodontally healthy controls. Plaque index (PI), probing pocket depth (PPD), clinical attachment level (CAL) and bleeding on probing (BOP) were recorded. GDF-15, SMAD2, SMAD5, SMAD6 and IL-6 levels were measured using ELISA. GCF SMAD5 and SMAD6 were significantly lower in periodontitis (p < 0.0001 and p = 0.0057, respectively), whereas salivary GDF-15 and both GCF and salivary IL-6 were higher than controls (p = 0.0177, p = 0.0008, and p = 0.0017, respectively). GCF GDF-15 did not differ significantly between groups (p = 0.0814). GCF SMAD6 correlated negatively with GCF IL-6 (r = − 0.461, p = 0.0016) and PPD, PI, BOP, and CAL (r = − 0.448 to − 0.353, p < 0.05). GCF IL-6 correlated positively with PPD, PI, and CAL (r = 0.309–0.353, p < 0.05). ROC discriminatory performance was highest for GCF IL-6 (AUC = 0.786, p < 0.001) and GCF SMAD5 (AUC = 0.770, p < 0.001). Stage III/Grade B periodontitis was associated with increased salivary GDF-15, increased IL-6 levels in both GCF and saliva, and decreased GCF SMAD5 and SMAD6 levels, suggesting an altered inflammatory and SMAD-related oral-fluid biomarker profile. GCF IL-6 and GCF SMAD5 may represent candidate adjunctive biomarkers for further evaluation in larger independent cohorts alongside conventional clinical periodontal parameters. Clinical trial registration: NCT07201142.",
  "abstract_shown": true,
  "affiliations": [
    "Faculty of Dentistry, Department of Periodontology, Istanbul Medipol University"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Dorukhan Ucar"
    },
    {
      "affs": [
        0
      ],
      "name": "Naif Mert Yilmaz"
    },
    {
      "affs": [
        0
      ],
      "name": "Anil Yilmaz"
    },
    {
      "affs": [
        0
      ],
      "name": "Melis Yilmaz"
    },
    {
      "affs": [
        0
      ],
      "name": "Nur Balci"
    },
    {
      "affs": [
        0
      ],
      "name": "Hilal Toygar"
    },
    {
      "affs": [
        0
      ],
      "name": "Emrah Turkmen"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5q1vr8eazws22.bib",
  "cited_by": 0,
  "doi": "10.1038/s41598-026-63757-9",
  "fulltext_url": "https://doi.org/10.1038/s41598-026-63757-9",
  "id": "5q1vr8eazws22",
  "issns": [
    "2045-2322"
  ],
  "landing_url": "https://doi.org/10.1038/s41598-026-63757-9",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "lcc",
      "Q"
    ],
    [
      "lcc",
      "R"
    ],
    [
      "openalex",
      "3506|Oral microbiology and periodontitis research"
    ]
  ],
  "openalex": "W7170900598",
  "pdf_url": "https://www.nature.com/articles/s41598-026-63757-9_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-07-01",
  "publisher": "Nature Portfolio",
  "ris": "https://research.draconitic.com/paper/5q1vr8eazws22.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T13:45:54Z",
      "native_id": "e315b35947d2468c8eb5e4662a0482dc",
      "source": "doaj",
      "url": "https://doi.org/10.1038/s41598-026-63757-9"
    }
  ],
  "subjects": [
    {
      "field": "medicine",
      "origin": "lcc:R",
      "subfield": "general"
    }
  ],
  "title": "Salivary growth differentiation factor-15 is elevated with reduced gingival crevicular fluid SMAD5 and SMAD6 levels in periodontitis: a cross-sectional study",
  "title_text": "Salivary growth differentiation factor-15 is elevated with reduced gingival crevicular fluid SMAD5 and SMAD6 levels in periodontitis: a cross-sectional study",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T13:45:54Z",
  "url": "https://research.draconitic.com/paper/5q1vr8eazws22",
  "venue": "Scientific Reports",
  "versions": []
}