The past two decades have seen an expanding body of literature documenting associations between oral diseases — particularly periodontitis — and systemic conditions such as type 2 diabetes mellitus (T2DM), cardiovascular disease (CVD), adverse pregnancy outcomes, and respiratory infections. The mechanistic pathways include chronic inflammation, translocation of oral microbes or microbial products into the circulation, and immune modulation triggered by oral dysbiosis (Rajasekaran et al., 2024; Pisano et al., 2023). At the same time, preventive and therapeutic oral care delivered by dental hygienists can measurably reduce oral inflammatory burden and improve patient knowledge and behaviors. For clinicians trained in oral–systemic healthcare, translating this evidence into routine, collaborative preventive practice is essential. October's National Dental Hygiene Month (NDHM) is an annual, high-visibility opportunity to align clinical practice change, community outreach, and interprofessional collaboration around these goals (American Dental Hygienists' Association [ADHA], 2024).
Consensus statements and classification updates have reframed periodontitis as a chronic, inflammatory non-communicable disease with systemic implications (Papapanou et al., 2018). Large observational studies and systematic reviews report associations between periodontitis and increased risk of cardiovascular disease events, though causality remains incompletely established and effect sizes vary by study design and confounding control (Herrera et al., 2024; Leng et al., 2023). Importantly, periodontal inflammation corresponds to systemic markers (e.g., C-reactive protein) and may act as a persistent inflammatory stimulus that interacts with atherosclerotic disease pathways (Stewart et al., 2016; Leng et al., 2015).
Periodontitis and diabetes exhibit a bidirectional relationship: poorly controlled diabetes increases susceptibility to periodontitis, and periodontal inflammation may worsen glycemic control. Meta-analyses of randomized and observational studies suggest that non-surgical periodontal therapy can produce a modest but clinically relevant reduction in HbA1c (approximately 0.3–0.6% in some meta-analyses) at 3 months, although heterogeneity between trials exists and longer-term effects are less certain (Teeuw et al., 2010; Teshome et al., 2017). These findings support periodontal care as an adjunctive component in comprehensive diabetes management.
Emerging data link oral dysbiosis with respiratory infections, adverse pregnancy outcomes, chronic kidney disease, and neurologic conditions through mechanisms involving aspiration of oral pathogens, systemic dissemination of microbial products, and immune activation (Pisano et al., 2023; Rajasekaran et al., 2024). While causal pathways vary and evidence quality differs by condition, the consistency of oral–systemic associations across disciplines argues for an integrated prevention strategy.
(Load-bearing statements above supported by multiple reviews and consensus reports — see Papapanou et al., 2018; Teeuw et al., 2010; Pisano et al., 2023; Herrera et al., 2024; Leng et al., 2023.)
Multiple systematic reviews and meta-analyses indicate that periodontal therapy reduces local inflammation and can improve intermediate systemic outcomes (e.g., glycemic control, systemic inflammatory markers) (Teeuw et al., 2010; Teshome et al., 2017). Evidence for reduction in hard cardiovascular endpoints is less definitive; observational data show associations between periodontitis and CVD, and some trials suggest improvements in surrogate markers after periodontal therapy, but large-scale randomized trials with cardiovascular endpoints remain limited (Herrera et al., 2024; Leng et al., 2015). Nonetheless, the weight of evidence supports that reducing oral inflammation is biologically plausible and clinically prudent as part of overall chronic disease risk reduction.
Dental hygienists are trained in risk assessment, instrumentation, patient education, behavioral modification strategies, and application of preventive agents. Historical and contemporary literature frames the dental hygienist as an essential prevention professional capable of leading community oral health efforts and functioning collaboratively within interprofessional teams (Ohrn, 2004; AAOSH, 2024). In oral–systemic models, hygienists frequently perform screening (e.g., periodontal charting, risk stratification), apply evidence-based preventive therapies (scaling, polishing, local antimicrobials when indicated), and provide counseling on tobacco cessation, diet, and home care — all of which influence systemic disease risk.
Examples of high-impact hygiene-led interventions include chairside diabetes screening referrals, coordinated care pathways with primary care for patients with poorly controlled glycemia, enhanced documentation of systemic risk factors in dental records, and implementation of quality metrics tied to systemic health outcomes (Prasad et al., 2019; Nayak et al., 2025). These models harness hygienists’ accessibility and preventive focus to bridge gaps between dental and medical care.
NDHM (October) is promoted by the ADHA and partner organizations and provides an annual window for intensified community outreach, professional education, policy advocacy, and interprofessional programming (ADHA, 2024). For oral–systemic healthcare initiatives, NDHM can be used to:
By concentrating messaging and measuring impact during NDHM, organizations can amplify reach and create data to support sustained programs.
Barriers include siloed health records, variable reimbursement for preventive services, workforce scope limitations in some jurisdictions, and the need for large-scale randomized trials linking periodontal interventions to major systemic endpoints. Future research should prioritize pragmatic trials of hygiene-led screening and referral models, cost-effectiveness analyses, and longitudinal studies that combine microbiome, immunologic, and clinical endpoints to clarify causality and mechanisms (Rajasekaran et al., 2024; Nayak et al., 2025).
For clinicians and organizations committed to oral–systemic health, dental hygienists are indispensable partners whose preventive skills and patient access position them to reduce oral disease burden and contribute meaningfully to systemic health. National Dental Hygiene Month is an underutilized yet powerful annual opportunity to pilot and promote programs that integrate oral health into broader healthcare delivery. By leveraging evidence-based hygiene practices, establishing care pathways, and measuring outcomes, oral–systemic healthcare teams can transition from associative science to demonstrable improvements in population health.
Periodontal Disease and Biofilm Diseases of the Mouth