Influence of obesity and periodontal treatment on defensin levels in the gingival crevicular fluid of patients with periodontitis

• Grant number: 24/17215-4
• Support Opportunities: Scholarships in Brazil - Master
• Start date: July 01, 2025
• End date: February 28, 2026
• Field of knowledge: Health Sciences - Dentistry - Periodontology
• Principal Investigator: Daniela Leal Zandim-Barcelos
• Grantee: Amanda Gonçalves Franco
• Host Institution: Faculdade de Odontologia (FOAr). Universidade Estadual Paulista (UNESP). Campus de Araraquara. Araraquara , SP, Brazil

Abstract

Periodontitis is a chronic inflammatory disease, induced by bacteria, that causes destruction of tooth-supporting tissues. Antimicrobial peptides are important components of the innate immune response and one of the main defense mechanisms of the gingival sulcus, exhibiting antimicrobial activity against a broad spectrum of Gram-negative and positive bacteria, fungi and viruses, in addition to regulating early inflammatory events and enhancing adaptive immunity. Defensins are the predominant antimicrobial peptides in humans. Research conducted by our research group has shown that there is a difference in the regulation of these peptides in healthy and diseased periodontal sites. In addition, antimicrobial peptides have been considered a possible mechanistic link between periodontal disease and its risk factors. Thus, the aim of this clinical study is to evaluate the influence of obesity and non-surgical periodontal treatment (NSPT) on the levels of beta-defensins (HBD) 1, 2 and 3 in the gingival crevicular fluid (GCF) of patients with periodontitis. Furthermore, the possible association between the levels of HBDs and inflammatory mediators (IL-1beta, IL-6, IL-10, TNFalfa) in the GCF of sites with periodontal disease activity before and after non-surgical periodontal treatment will be investigated. Forty-four patients in good general health with stage III or IV periodontitis, twenty-two obese (BMI > 30 kg/m2) and twenty-two non-obese, will be included in the study. The following clinical parameters will be evaluated: visible plaque index, gingival bleeding index, probing depth (PD), bleeding on probing (BS) and clinical attachment level (CAL). One week after the clinical examination, CAL will be collected from 3 non-adjacent sites showing clinical signs of periodontitis (PD ¿ 5 mm, SS and CAL ¿ 5 mm) and from 3 non-adjacent sites without periodontal disease (PD ¿ 3 mm, absence of SS and clinical attachment loss). Then, the NCPT will be performed by a single operator, through scaling and root planing (SRP). After 1 and 3 months after the end of the treatment, the clinical parameters will be reassessed and new GCF collections will be performed from the previously selected teeth. The quantification of antimicrobial peptides in GCF will be done using the sandwich ELISA technique and inflammatory mediators using a multiplex assay. Appropriate statistical analyses will be performed, according to the data distribution, to compare the clinical and immunological data before and after treatment of obese and non-obese patients.