Air Pollution as a Risk Indicator for Periodontitis

Air Pollution and Oral Health: An Overall Insight From Genetic Causality

BACKGROUND

A growing body of epidemiological data consistently links air pollution to various adverse health outcomes. However, the potential connection between air pollution and the risk of oral diseases remains underexplored.

METHODS

This study utilized a two-sample Mendelian randomization approach to assess the causal relationship between air pollution and oral diseases. Six categories of air pollution were considered as exposures: nitrogen oxides (NOx), nitrogen dioxide (NO2), particulate matter (PM2.5, PM2.5-10, PM10), and PM2.5 absorbance. The outcomes included 18 oral health-related diseases drawn from the Finngen R10 dataset, the Gene-Lifestyle Interactions in Dental Endpoints consortium, and the Oncoarray oral cavity and oropharyngeal cancer consortium. Sensitivity analyses were performed to validate the primary inverse-variance weighted estimates using methods such as weighted median, weighted mode, and MR Egger.

RESULTS

The inverse-variance weighted analysis demonstrated a detrimental effect of air pollution on multiple oral health conditions, yielding 5 positive associations including PM2.5 with oral leukoplakia, gingivitis and periodontitis; PM2.5-10 with pulp and periapical diseases, and NO2 with gingivitis and periodontitis, and oral cavity, salivary glands and jaws diseases. Sensitivity tests showed no evidence of heterogeneity or pleiotropy, affirming the robustness of the findings.

CONCLUSION

This study highlights the detrimental impact of air pollution on oral health, emphasizing the need for further research into the underlying mechanisms and interactions. These findings reinforce the importance of implementing environmental interventions to mitigate the associated risks for oral health.

Mediating role of immune cells in association between volatile organic compounds and periodontitis: NHANES 2011-2014

BACKGROUND

The relationship between humans and volatile organic compounds (VOCs) is a persistent concern due to their widespread sources and high evaporation rates. However, there is currently limited direct evidence linking VOC exposure to the development of periodontitis.

METHODS

This cross-sectional study analyzed 1525 participants and 21 urinary VOCs in the National Health and Nutrition Examination Survey (NHANES) from 2011 to 2014, aiming to investigate the relationship between periodontitis risk, assessed by attachment loss (AL) and probing depth (PD) and individual VOCs using logistic regression, quantile regression, and subgroup analysis. Weighted quantile sum analysis (WQS) and subgroup analysis were utilized to evaluate whether VOC mixtures were associated with periodontitis risk. Multiple linear regression models were used to examine the association between VOC co-exposure and peripheral immune cell counts. A mediation analysis was performed to evaluate whether peripheral immune cells are involved in the effect of VOC co-exposure on periodontitis prevalence.

RESULTS

Urinary levels of 2-aminothiazoline-4-carboxylic acid, mandelic acid, and N-acetyl-S-(4-hydroxy-2-butenyl)-L-cysteine were positively associated with the risk of periodontitis after adjusting for all covariates. The WQS models demonstrated a positive correlation between the mixture of VOCs and the risk of periodontitis, wherein 2-aminothiazoline-4-carboxylic acid emerged as the most important contributor. The mediation analysis suggested that monocytes may play a role in the observed association between VOC co-exposure and the prevalence of periodontitis.

CONCLUSIONS

Exposure to VOCs is associated with a greater prevalence of periodontitis. Monocytes' mediating role plays a crucial function in the association between the risk of periodontitis and co-exposure to VOCs.

PLAIN LANGUAGE SUMMARY

Volatile organic compounds (VOCs) are chemicals that evaporate quickly and are found all around us-from paints to cleaning products. Understanding how these compounds affect our health is crucial, especially regarding conditions like periodontitis, a common oral chronic inflammatory disease. In our study, we looked at urine samples from 1525 people who participated in a national health survey between 2011 and 2014 to find out if there is an association between VOC exposure and the risk of developing periodontitis. We found that certain chemicals in the urine, which show VOC exposure, were indeed associated with a greater risk of the disease. We further investigated the collective impact of these VOCs on the risk of periodontitis, revealing that certain chemicals exert a more significant influence than their counterparts. Additionally, our research hints at a potential role for monocytes in the interplay between VOCs and the risk of periodontitis. Our data suggest that exposure to VOCs could be associated with a greater likelihood of periodontitis, with monocytes potentially playing a role in this relationship. This study helps us better understand the potential health impacts of daily chemical exposure and underscores the importance of investigating further how our environment affects our health.

Particulate Matter 2.5 and Severe Periodontitis Among Colombian Adults

AIMS

The primary aim was to determine the association between particulate matter 2.5 (PM2.5) concentration at municipality-level and severe periodontitis among adults. A second aim was to evaluate contemporaneous versus lagged effects of exposure to municipality-level PM2.5 concentration on severe periodontitis.

METHODS

We linked individual-level data from the latest National Oral Health Survey (ENSAB-IV) with satellite-based estimates of annual PM2.5 concentrations at the surface level for municipalities in Colombia. Annual PM2.5 concentrations were averaged over 3, 5 and 10  years to capture contemporaneous and lagged effects, respectively. Severe periodontitis was defined using three common case definitions. The association between municipality-level PM2.5 concentration and severe periodontitis was tested in multilevel logistic regression models adjusting for covariates.

RESULTS

Data from 9111 adults in 197 municipalities and 33 departments were analyzed. The prevalence of severe periodontitis varied from 10.4% to 29.8% depending on the case definition used. The mean PM2.5 concentration was 18.5 (SD = 2.9), 19.1 (3.0) and 18.9 (2.8) μg/m3 over the past 3, 5 and 10 years. The municipality-level PM2.5 concentration was not associated with severe periodontitis, irrespective of the assessment period for PM2.5 concentration (3, 5, or 10  years) or the case definition of periodontitis used.

CONCLUSIONS

This study found no association between municipality-level PM2.5 concentration and severe periodontitis among Colombian adults. No evidence of lagged effects was found either.

Functions of Hemp-Induced Exosomes against Periodontal Deterioration Caused by Fine Dust

Although fine dust is linked to numerous health issues, including cardiovascular, neurological, respiratory, and cancerous diseases, research on its effects on oral health remains limited. In this study, we investigated the protective effects of mature hemp stem extract-induced exosomes (MSEIEs) on periodontal cells exposed to fine dust. Using various methods, including microRNA profiling, PCR, flow cytometry, immunocytochemistry, ELISA, and Alizarin O staining, we found that MSE treatment upregulated key microRNAs, such as hsa-miR-122-5p, hsa-miR-1301-3p, and hsa-let-7e-5p, associated with vital biological functions. MSEIEs exhibited three primary protective functions: suppressing inflammatory genes while activating anti-inflammatory ones, promoting the differentiation of periodontal ligament stem cells (PDLSCs) into osteoblasts and other cells, and regulating LL-37 and MCP-1 expression. These findings suggest that MSEIEs have potential as functional biomaterials for applications in pharmaceuticals, cosmetics, and food industries.

Short- and medium-term exposure to ambient air pollution and periodontal status

We investigated the association between ambient air pollutant exposure and periodontal health using data from 17,271 adults in the Korea National Health and Nutrition Examination Survey (2012-2015). Participants' periodontal status was categorized based on their community periodontal index (CPI) scores. Using multiple logistic regression models, we examined the relationship between air pollutant levels and poor periodontal status at various lag periods. After adjusting for potential confounders, PM10 exposure was associated with a poor periodontal status (short-term: 0-1 and 0-2 lag days; medium-term: 0-1 and 0-2 lag months). SO2 exposure showed similar associations (short-term, 0-2 to 0-7 lag days; medium-term, 0-4 to 0-6 lag months). Only increased medium-term O3 exposure (0-2 to 0-6 lag months) was associated with a poor periodontal status. NO2 exposure was inversely associated with poor periodontal status for both short- and medium-term durations.

Associations of Urinary Total Arsenic and Arsenic Species and Periodontitis

AIMS

Arsenic exposure is a significant global public health concern and has been implicated in endocrine disruption and increased oxidative stress, both of which are crucial pathogenic mechanisms of periodontitis. This study aimed to investigate the association of urinary total arsenic and arsenic species with periodontitis and to further explore the potential mediating roles of sex hormones and oxidative stress indicators.

METHODS

Data used in this study were derived from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) in the US population. In all, 1063 participants with complete data were included in this study. Weighted logistic regression analyses were used to evaluate the relationship between urinary arsenic and periodontitis. Mediation analyses were used to explore the effects of potential mediators on these associations.

RESULTS

High concentrations of urinary dimethylarsinic acid (DMA), monomethylarsonic acid (MMA), 2 types of toxic urinary arsenic (TUA2), and 4 types of toxic urinary arsenic (TUA4) were positively related to periodontitis (P < .05). After adjusting for potential confounders, the positive association remained significant (odds ratio, 1.32; 95% confidence interval, 1.01-1.71). Testosterone may partially mediate the relationship between MMA and periodontitis, with mediating effects of 21.78% and 39.73% of the total effect. No significant mediation effect of oxidative stress indicators was found for this relationship.

CONCLUSIONS

This study reports a positive association between urinary MMA and periodontitis, and testosterone may mediate this relationship. Our findings serve as a call for action to avoid the deployment of arsenic-containing therapeutic agents as treatment modalities for oral afflictions.

The Correlation between Oral Health and Air Pollution: A Systematic Review

This systematic review assessed to evaluate the potential correlation between oral health and air pollution. To the best of the authors' knowledge, this is the first systematic review endeavoring to compare air pollution and oral health. A systematic search was performed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-analyses) statement and employed the PICO(S) approach (Patient or Population, Intervention, Control or Comparison, Outcome, and Study types). The search was limited to English-language articles, and publications within a 15-year timeframe were included in the electronic search. A comprehensive search was conducted across PubMed, Scopus, Embase, and Web of Science databases, spanning the years 2008 to 2023, resulting in a total of 4983 scientific articles. A final selection of 11 scientific papers was made based on their study type and the specific air pollutants examined. The selected papers analyzed various air pollutants associated with health-related diseases, including Ozone, Nitrogen Dioxide, Nitrogen Monoxide, Carbon Monoxide, sulfur dioxide, and particulate matter. Three out of eleven of the reviewed studies assert a strong correlation between air pollutants and oral diseases, specifically periodontitis. However, the exact biological mechanisms underlying this correlation do not seem to be fully understood, indicating the need for further comprehensive investigation in this regard. Dentists can contribute to the collective effort by educating their patients about the oral health implications of air pollution, thereby supporting initiatives aimed at promoting environmental and health sustainability.

Treatment of periodontitis ameliorates the severity and extent of psoriasis-A randomized clinical trial

AIM

To assess the impact of non-surgical periodontitis treatment over conventional dermatological treatment on the severity and extent of psoriasis in patients affected by comorbid psoriasis and periodontitis.

METHODS

Seventy-four patients affected by both psoriasis and Stages I-IV periodontitis were randomized to receive either Steps 1-2 (non-surgical) of periodontal therapy (test group; n = 37) or no treatment (control group; n = 37). The two groups were balanced in terms of psoriasis medications, with the majority of the included patients undergoing biologics (74.0%) as monotherapy, while minor proportions were under systemic medications (13.7%) or none/topical/phototherapy (12.3%). The psoriasis area severity index (PASI) was regarded as the primary outcome. The Body Surface Area (BSA) and the Dermatology Life Quality Index (DLQI) were additionally considered as dermatological outcomes. Probing pocket depth, recession depth, clinical attachment level, periodontal inflamed surface area, and full-mouth plaque and bleeding scores were also measured. [Correction added on July 5, 2024, after first online publication: The preceding sentence has been revised].

RESULTS

Periodontal therapy in the test group led to statistically significant lower PASI scores at 10 weeks (mean = 3.15; standard deviation [SD] = 3.78) compared to the control group (mean = 7.11; SD = 6.09) (mean difference [MD] = -4.0; 95% confidence interval [CI]: -6.3, -1.6; p = .001). The test group also showed improvements in BSA (MD = -4.3) and periodontal parameters compared to the control group. DLQI only showed a non-statistically significant tendency (MD = -2.0).

CONCLUSION

Steps 1-2 of periodontal therapy showed an additional effect over conventional dermatological treatment in reducing the severity and extent of psoriasis (Clinicaltrials.gov: NCT05311501).

Association of environmental polycyclic aromatic hydrocarbons exposure with periodontitis in NHANES 2009-2014: A mixtures approach

BACKGROUND

Polycyclic aromatic hydrocarbons (PAHs) can invade and cause harm to the human body through various pathways, but there is currently little research on the relationship between mixed-PAHs exposure and periodontitis. The purpose of this study was to examine the effects of mixed-urinary PAHs exposure on periodontitis in adults in the United States.

METHODS

The cross-sectional study included 2749 subjects selected from the National Health and Nutrition Examination Survey (NHANES) 2009-2014 cycles. A professional examination of the periodontal status was conducted to distinguish between periodontitis and non-periodontitis based on the Centers for Disease Control and Prevention/American Academy of Periodontology (CDC/AAP) case definition. Laboratory testing of urine samples was performed to obtain the levels of urinary PAHs. Pearson correlation coefficients were utilized to determine the degree of correlation between urinary PAHs, while weighted binary logistic regression and Bayesian kernel machine regression (BKMR) were employed to evaluate the relationship between urinary PAHs and periodontitis.

RESULTS

In a single-exposure model, 3-hydroxyfluorene (OH-3F), 2-hydroxyfluorene (OH-2F), 1-hydroxyphenanthrene (OH-1Ph), and 2-hydroxyphenanthrene and 3-hydroxyphenanthrene (OH-2,3Ph) were positively associated with periodontitis risk. In the mixed-exposure model, BKMR analysis demonstrated that mixed exposure to urinary PAHs was positively associated with periodontitis, with OH-2F being the most critical factor for the overall mixed effects (posterior inclusion probability [PIP] = 0.98). Univariate exposure-response function and univariate effects analysis revealed a positive correlation between urinary OH-2F levels and periodontitis.

CONCLUSIONS

The study reveals a significant positive correlation between exposure to mixed PAHs and periodontitis, with a particular emphasis on the pivotal role of OH-2F. Mitigating PAHs in the environment may serve as a preventive measure against periodontitis and alleviate its global public health burden.

The effect of air pollution exposure on the risk of outpatient visits for periodontitis: a time-series study

This study aimed to determine if air pollution affected the risk of periodontitis outpatient visits. We collected the records of 56,456 periodontitis outpatient visits in Hefei, China, from January 1, 2014 to December 31, 2021. The relationship between air pollution and periodontitis outpatient visits was evaluated using distributed lag nonlinear and generalized linear models. Additional analyses were performed, stratifying the data by age, season, and sex. Subgroup analyses showed a significantly higher risk of periodontitis outpatient visits due to NO2 exposure during the warm season compared with the cold season. Moreover, O3 exposure was associated with a lower risk of periodontitis outpatient visits in the cold season. The findings suggest that NO2 exposure is associated with an increased risk of periodontitis outpatient visits, whereas O3 exposure is associated with a decreased risk of periodontitis outpatient visits. Season is found to be an effect modifier in these associations.

From Basic Science to Clinical Practice: A Review of Current Periodontal/Mucogingival Regenerative Biomaterials

Periodontitis is a dysbiosis-driven inflammatory disease affecting the tooth-supporting tissues, characterized by their progressive resorption, which can ultimately lead to tooth loss. A step-wise therapeutic approach is employed for periodontitis. After an initial behavioral and non-surgical phase, intra-bony or furcation defects may be amenable to regenerative procedures. This review discusses the regenerative technologies employed for periodontal regeneration, highlighting the current limitations and future research areas. The search, performed on the MEDLINE database, has identified the available biomaterials, including biologicals (autologous platelet concentrates, hydrogels), bone grafts (pure or putty), and membranes. Biologicals and bone grafts have been critically analyzed in terms of composition, mechanism of action, and clinical applications. Although a certain degree of periodontal regeneration is predictable in intra-bony and class II furcation defects, complete defect closure is hardly achieved. Moreover, treating class III furcation defects remains challenging. The key properties required for functional regeneration are discussed, and none of the commercially available biomaterials possess all the ideal characteristics. Therefore, research is needed to promote the advancement of more effective and targeted regenerative therapies for periodontitis. Lastly, improving the design and reporting of clinical studies is suggested by strictly adhering to the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement.

Association between polycyclic aromatic hydrocarbons and periodontitis: Results from a large population-based study

AIM

To explore the association between polycyclic aromatic hydrocarbons (PAHs) (measured using urinary metabolites) and periodontitis using data from the National Health and Nutrition Examination Survey 2009-2014.

MATERIALS AND METHODS

Weighted binary logistic regression, Bayesian kernel machine regression (BKMR) and weighted quantile sum (WQS) regression were used to evaluate independent and joint associations between the six urinary monohydroxylated metabolites of PAHs (OH-PAHs) and periodontitis.

RESULTS

In all, 3413 participants were included in this study. All six urinary OH-PAHs were present at higher levels in the periodontitis group compared with the non-periodontitis group (p < .001). Fully adjusted multivariable logistic regressions showed positive associations between the six urinary OH-PAHs and periodontitis (p < .05). Higher concentrations of OH-PAHs were also positively associated with attachment loss, periodontal pocket depth (PPD) and the number of tooth loss. BKMR and WQS regression yielded similar positive associations between OH-PAH mixtures and periodontitis.

CONCLUSIONS

PAHs and their mixture are positively associated with periodontitis, which may provide novel insights into periodontitis prevention from an environmental exposure perspective.

The co-occurrence of the two main oral diseases: periodontitis and dental caries

OBJECTIVES

Limited studies are available testing through multiple regression models the association between the two main oral diseases: dental caries and periodontitis. The aim of this cross-sectional population-based study was to verify whether dental caries and periodontitis co-occur in a representative sample of the South Korea population.

MATERIALS AND METHODS

A total of 23,405 subjects representative of 36.2 million of adults (KNHANES) were examined. Univariate and multiple regression analyses using 7 different models were applied, controlling for age, gender, smoking status, frequency of toothbrushing, use of interproximal toothbrushes and flossing, educational level, income, gum diseases treatment and tooth filling in the previous year, BMI, Vitamin D serum levels, alcoholism, diabetes status, stress and carbohydrates dietary intake.

RESULTS

In the fully adjusted model, participants with periodontitis had, respectively, a mean of 0.82 (95% CI: 0.41-1.23) and of 0.36 (95% CI: 0.22-0.50) more untreated decayed surfaces and teeth than participants without periodontitis, with an OR to have at least one untreated decayed surface of 1.96 (95% CI: 1.66-2.32). However, cumulative caries experience (DF scores) and periodontitis were not associated.

CONCLUSIONS

In this large nationally representative population, periodontitis and untreated dental caries co-occur. However, when considering cumulative caries experience (DF scores), the two diseases do not appear related.

CLINICAL RELEVANCE

In light of their possible co-occurrence, clinicians should implement integrative diagnostic, preventive and treatment strategies for both diseases.

The Gum-Gut Axis: Periodontitis and the Risk of Gastrointestinal Cancers

Periodontitis has been linked to an increased risk of various chronic non-communicable diseases, including gastrointestinal cancers. Indeed, dysbiosis of the oral microbiome and immune-inflammatory pathways related to periodontitis may impact the pathophysiology of the gastrointestinal tract and its accessory organs through the so-called "gum-gut axis". In addition to the hematogenous spread of periodontal pathogens and inflammatory cytokines, recent research suggests that oral pathobionts may translocate to the gastrointestinal tract through saliva, possibly impacting neoplastic processes in the gastrointestinal, liver, and pancreatic systems. The exact mechanisms by which oral pathogens contribute to the development of digestive tract cancers are not fully understood but may involve dysbiosis of the gut microbiome, chronic inflammation, and immune modulation/evasion, mainly through the interaction with T-helper and monocytic cells. Specifically, keystone periodontal pathogens, including Porphyromonas gingivalis and Fusobacterium nucleatum, are known to interact with the molecular hallmarks of gastrointestinal cancers, inducing genomic mutations, and promote a permissive immune microenvironment by impairing anti-tumor checkpoints. The evidence gathered here suggests a possible role of periodontitis and oral dysbiosis in the carcinogenesis of the enteral tract. The "gum-gut axis" may therefore represent a promising target for the development of strategies for the prevention and treatment of gastrointestinal cancers.

Research on the Association Between Periodontitis and COPD

Periodontitis is a common chronic bacteria-initiated inflammatory disease that is closely associated with various systemic diseases, including chronic obstructive pulmonary disease (COPD). Periodontitis and COPD share similar risk factors, pathology and microorganisms. Epidemiological and clinical research have shown positive correlation between the two diseases. Individuals with severe periodontitis had a higher risk of developing COPD. Moreover, the relative risk of COPD in severe periodontitis was much higher compared to people without periodontal disease and patients with mild to moderate periodontitis. COPD patients with periodontitis had a higher frequency of COPD exacerbation and periodontal treatment demonstrated some control of COPD. However, the nature of periodontitis affecting COPD still needs further exploration. Periodontitis caused microbial and immune imbalances of the lung through several aspects: (I) under periodontitis status, periodontal pathogens directly caused the lung inflammatory reaction after inhalation and colonization on the lung, (II) periodontitis status promoted the oral colonization of pneumonia-associated pathogens, (III) periodontitis status affected the respiratory epithelium structure and (IV) periodontitis status caused imbalances in neutrophils, macrophages and inflammatory cytokines. In this review, we conclude the association between periodontitis and COPD through several aspects and further discuss the potential mechanism by which periodontitis affects COPD.