Biofluid derived extracellular vesicles in periodontitis and peri-implantitis

o Baseline and initial treatment visit (0-month; 1 hour duration) o Pre-operative periodontal charting recorded by registered periodontists (Ivanovaki, Lee, and other relevant staff) or DClinDent postgraduate registrars, with a periodontal UNC probe. All examiners will be calibrated. o This will allocate participants into the group categories: Group #1: periodontal health, gingivitis and periodontitis (with and without systemic diseases); Group #2: peri-implant health, peri-implant mucositis and peri-implantitis (with and without systemic diseases) o Saliva, gingival crevicular fluid (GCF) and plaque samples will be collected from all Group #1 patients; saliva, Peri-Implant Crevicular Fluid (PICF) and dental plaque will be collected from all Group #2 patients - For saliva collection: 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 and PICF 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 healthy patients: 4 paper strips will be collected each from 4 healthy sites (free of inflammation and BOP) from the same tooth and pooled. - For gingivitis patients: 6 paper strips will be collected from 6 inflamed sites (or 2 sites from the same tooth) - For periodontitis/peri-implant diseased patients: up to 6 paper strips will be collected each from 1 deepest site and 1 healthy site o Plaque, GCF/PICF and saliva samples will be placed in sterile glycerol (final concentrations: 15-30%), or stored immediately at -80 degrees at the Research Lab, Level 6, Oral Health Centre, until elution and extraction. Samples containing glycerol may be subjected to in vitro culturing for biofilm development prior to the extraction of bacterial EVs from the cultured media. EVs will be isolated, characterised and omics (proteome, methylome, microbiome, lipidome and metabolome or relevant omes), with saliva, GCF/PICF and plaque samples used as controls. Patients in the periodontitis group 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 appointments (60-90 mins duration per appointment). Follow-up reviews (3-, 6- and 12-mo post-periodontal or post-peri-implant treatment; 1-1.5 hours duration) o Periodontitis or peri-implantitis patients will be recalled 3 mo following debridement to re-assess periodontal parameters and recollect saliva and GCF (from the same sites as baseline appointment). Patients with peri-implant diseases (peri-implant mucositis and peri-implantitis) will undergo non-surgical periodontal implant therapy, as per EFP S3 level clinical practice guideline (PMID: 37271498), which includes supra- and sub-marginal mechanical instrumentation using titanium and/or stainless steel area-specific curettes, and ultrasonic/ sonic instruments. The use of air-polishing devices with glycine powder will be limited to supra-marginal instrumentation (subject to the presentation and access in a given case). o 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. o Patients will then be recalled at the 6 and 12 mo time points (since initial therapy) o Peri-implant disease patients may be undergoing peri-implant surgery treatment if patients are not responding to non-surgical peri-implant treatment. o Patient compliance with treatment reviews will be recorded using a clinic attendance checklist. The diagnosis of extracellular vesicles (EVs) in patients with periodontitis and peri-implantitis will be compared to investigate the distinct mechanisms of disease pathogenesis related to EVs.