Host and microbial derived extracellular vesicles in oral biofluids in periodontitis patients with and without Type 2 Diabetes Mellitus.

Baseline and initial treatment visit (0-month; 1 hour duration) Pre-operative periodontal charting recorded by registered periodontists or DClinDent postgraduate registrars, with a periodontal UNC-15 probe. All examiners will be calibrated. This will allocate participants into the group categories: Group #1: Periodontally Healthy groups Group #2: Periodontitis (Generalised Stage III-IV) without diagnosed Type 2 Diabetes Mellitus Group #3: Diagnosed T2DM (HbA1c greater than or equal to 6.5%)* with Periodontitis (Generalised Stage III-IV) (with and without systemic diseases); *According to the American Diabetes Association 2022 Saliva, gingival crevicular fluid (GCF) and plaque samples will be collected from all Group #1, #2 and #3 patients Participants will be asked to refrain from eating and drinking for at least one hour prior to saliva sample collection. At the appointment, participants will rinse their mouths with ~10 mL of water to remove the food debris. Unstimulated whole saliva through spitting (5mL ideally; minimum 1- 1.5ml) will be collected. GCF will be collected prior to commencing treatment to avoid contamination via blood. This will be conducted using our established protocol (Han et al, 2023, PMID: 35771077) where paper strips (Oraflow) will be inserted into the deepest site of each quadrant (to reduce saliva contamination) and pooled. For all patients: up to 6 paper strips will be collected each from 1 deepest site and 1 healthy site All patients will be allocated the next available appointment for standard care, receiving supragingival and subgingival non-surgical debridement using hand scalers and ultrasonic instruments over 2-4 appointments (60-90 mins duration per appointment). Follow-up reviews (3- and 6- mo post-periodontal treatment; 60-90 mins duration per appointment) All periodontitis patients with and without T2DM will receive the non-surgical instrumentation for the management of periodontitis as per European Federation of Periodontology S3-level clinical practice guideline. All periodontitis patients with and without T2DM will be recalled 3 months following debridement to re-assess periodontal parameters and recollect saliva, GCF and plaque (from the same sites as baseline appointment). They will then receive the standard protocol of care, including oral hygiene instruction (OHI), non-surgical re-instrumentation of persistent sites and supragingival maintenance of remaining sites. Patients will then be recalled at the 3-, 6- mo time points (since initial therapy) Patient compliance with treatment reviews will be recorded using a clinic attendance checklist. The diagnosis of extracellular vesicles (EVs) in periodontitis patients with and without diabetes will be compared to investigate the distinct mechanisms of disease pathogenesis related to EVs. Please note that all patients will receive routine standard of care of non-surgical periodontal treatment (NSPT), with no specific additional intervention applied. It is an observational longitudinal prospective study, with follow-up to 3, 6 and 12 months post non-surgical periodontal treatment (NSPT) for all periodontitis patients with and without type II diabetes. Clinical parameters and saliva, GCF and subgingival plaque samples will be collected at baseline, 3-, 6-, and 12-month time points.