Electronic nicotine delivery systems: Oral health implications and oral cancer risk

Aerosolized e-liquid base constituents induce cytotoxicity and genotoxicity in oral keratinocytes

OBJECTIVE

Electronic cigarette (e-cigarette) use among adults in the United States continues to rise. Particularly concerning is the impact of e-cigarette aerosol inhalation on the oral mucosa. Aerosols are derived from a heated e-liquid base of propylene glycol/glycerin (PG/G) often mixed with nicotine and chemical flavors. Of note, harmful and potentially harmful constituents (HPHCs), including metals and volatile organic compounds, have been detected in e-cigarette aerosols. It remains unknown, however, whether aerosols exclusively derived from e-liquid PG/G are detrimental to oral keratinocytes. The present study analyzed toxicological outcomes in normal oral keratinocytes exposed to model nicotine-free, unflavored PG/G e-liquid aerosols.

MATERIALS AND METHODS

Cell viability/cytotoxicity, genotoxicity, and immunoblotting assays were conducted in NOKSI, a gingiva-derived oral keratinocyte cell line, following exposure to model e-liquid aerosols or non-aerosolized controls. The HPHC acrolein, reported to form DNA adducts in the buccal mucosa from e-cigarette users, was also used in similar assays.

RESULTS

PG/G e-liquid aerosol extracts significantly enhanced cytotoxic and DNA damaging responses in NOKSI cells when compared to non-aerosolized e-liquid treatment. Acrolein treatment led to similar results.

CONCLUSIONS

The aerosolization process of PG/G e-liquid is a critical determinant of marked cytotoxic and genotoxic stimuli in oral keratinocytes.

The use of electronic cigarettes and other tobacco products among university students and their potential relationship with oral health: A cross-sectional study

BACKGROUND

The aim of this study was to evaluate oral alterations among university students and explore possible associations with tobacco consumption in its various forms.

METHODS

A cross-sectional study was conducted in 2 phases: the first phase involved administering an electronic questionnaire to participants determine the prevalence of tobacco use and the second phase involved a physical examination of the participants. The participants were grouped on the basis of their reported habits and compared using statistical analysis (P < .05).

RESULTS

Of the 620 participants, 57.1% reported using tobacco in some form, with 47.4% reporting electronic cigarette (e-cigarette) use. In the clinical phase, comparing the presence of oral changes in tobacco users vs nonusers, e-cigarette users had a higher proportion of white-spot caries lesions (P = .041) and gingivitis (P = .012). When e-cigarette use was combined with other forms of tobacco use, additional oral changes were more prevalent, including coated tongue and nicotinic stomatitis (P < .05).

CONCLUSIONS

The use of alternative forms of tobacco consumption is common among university students, with e-cigarette use being the most prevalent form, and may lead to detrimental effects on the oral cavity, such as caries and gingivitis, particularly when used in conjunction with other tobacco products.

PRACTICAL IMPLICATIONS

The use of tobacco in alternative forms, such as e-cigarettes, can affect oral health directly or indirectly. Dentists should be familiar with the characteristics of this population and the potential oral repercussions associated with tobacco use to address the impact on health and raise awareness of the associated risks.

Current thinking about the effects of e-cigarettes on oral cancer risk

In the last decade there has been a significant increase in the appeal and popularity of e-cigarettes. Recent national news headlines outline that one million smokers will be given a free vaping starter kit to encourage them to give up tobacco products. An independent report commissioned by the UK Government has cited promotion of vaping as a critical recommendation to ensuring England is smoke-free by 2030. Undoubtedly, the dental team will now encounter many more questions from patients keen to know more regarding the safety of electronic nicotine delivery systems and their effects on the oral cavity. However, it is often difficult to answer these questions due to a lack of evidence regarding their impact. Although there are some preliminary animal and in vitro data, additional well-designed, long-term studies are required to investigate oral health outcomes of e-cigarette use.We aim to summarise the latest evidence to better inform clinicians about the effects of vaping on oral health, particularly regarding the risks of oral cancer, so they can better inform their patients.

e-Cigarettes and Oral Cancer: what do we know so far?

We aim to summarise the latest evidence to better inform OMFS practitioners about the deleterious effects of vaping on oral health and the risks of oral cancer, so they can better inform their patients. Current evidence suggests that e-cigarette use is not risk-free.

Impact of Electronic Cigarettes on the Upper Aerodigestive Tract: A Comprehensive Review for Otolaryngology Providers

Objective

The use and effects of electronic (e)-cigarettes (e-cigs) are particularly relevant for otolaryngology providers as tobacco plays a major role in benign and malignant diseases of the upper aerodigestive tract. This review aims to (1) summarize the recent policies regarding e-cigs and important patterns of use and (2) serve as a comprehensive resource for clinical providers on the known biologic and clinical effects of e-cigs on the upper aerodigestive tract.

Data Sources

PubMed/MEDLINE.

Review Methods

We conducted a narrative review on (1) general information on e-cig use and informative findings in the lower respiratory system and a comprehensive review on (2) the effects of e-cigs on cell and animal models and the clinical implications of these products on human health as is relevant to otolaryngology.

Conclusions

Although e-cigs are likely less harmful than conventional cigarettes, preliminary research on e-cigs suggest several deleterious effects including in the upper aerodigestive tract. Due to this, there has been increased interest in restricting e-cig usage, particularly among the adolescent population, and caution in recommending e-cigs to current smokers.

Implications for Practice

Chronic e-cig use is likely to have clinical implications. It is critical for otolaryngology providers to be aware of the rapidly changing regulations and use patterns regarding e-cigs and how e-cigs influence human health, particularly with regards to the upper aerodigestive tract, to accurately council patients regarding potential risks and benefits of use.

Electronic Cigarette Use Promotes a Unique Periodontal Microbiome

Electronic cigarettes (e-cigs) have become prevalent as an alternative to conventional cigarette smoking, particularly in youth. E-cig aerosols contain unique chemicals which alter the oral microbiome and promote dysbiosis in ways we are just beginning to investigate. We conducted a 6-month longitudinal study involving 84 subjects who were either e-cig users, conventional smokers, or nonsmokers. Periodontal condition, cytokine levels, and subgingival microbial community composition were assessed, with periodontal, clinical, and cytokine measures reflecting cohort habit and positively correlating with pathogenic taxa (e.g., Treponema, Saccharibacteria, and Porphyromonas). α-Diversity increased similarly across cohorts longitudinally, yet each cohort maintained a unique microbiome. The e-cig microbiome shared many characteristics with the microbiome of conventional smokers and some with nonsmokers, yet it maintained a unique subgingival microbial community enriched in Fusobacterium and Bacteroidales (G-2). Our data suggest that e-cig use promotes a unique periodontal microbiome, existing as a stable heterogeneous state between those of conventional smokers and nonsmokers and presenting unique oral health challenges. IMPORTANCE Electronic cigarette (e-cig) use is gaining in popularity and is often perceived as a healthier alternative to conventional smoking. Yet there is little evidence of the effects of long-term use of e-cigs on oral health. Conventional cigarette smoking is a prominent risk factor for the development of periodontitis, an oral disease affecting nearly half of adults over 30 years of age in the United States. Periodontitis is initiated through a disturbance in the microbial biofilm communities inhabiting the unique space between teeth and gingival tissues. This disturbance instigates host inflammatory and immune responses and, if left untreated, leads to tooth and bone loss and systemic diseases. We found that the e-cig user's periodontal microbiome is unique, eliciting unique host responses. Yet some similarities to the microbiomes of both conventional smokers and nonsmokers exist, with strikingly more in common with that of cigarette smokers, suggesting that there is a unique periodontal risk associated with e-cig use.

The Effects of e-Cigarette Aerosol on Oral Cavity Cells and Tissues: A Narrative Review

A wealth of research has comprehensively documented the harmful effects of traditional cigarette smoking and nicotine on human health. The lower rate of exposure to harmful chemicals and toxic substances offered by alternative electronic smoking devices (e-cigarettes, vaping, etc.) has made these methods of smoking popular, especially among adolescents and young adults, and they are regarded frequently as safer than regular cigarettes. During vaporization of these so-called e-liquids, toxins, carcinogens and various other chemical substances may be released and inhaled by the user. Data on the potential human health effect attendant on exposure to e-vapor are based mainly on animal and in vitro studies. The oral tissues are the first locus of direct interaction with the components of the inhaled vapor. However, the short-term as well as long-term effects of the exposure are not known. The aim of the review is to briefly present data on the effects of the chemical components and toxins of e-cigarette vapor on oral cavity cells and tissues of oral health.

Men and Oral Health: A Review of Sex and Gender Differences

Sex and gender related health disparities in oral health remain an underappreciated and often over looked aspect of well-being. The goal of this narrative review is to identify sex and gender related oral health disparities by summarizing the current literature related to differences in oral health between men and women. The review identified that men are more likely to: ignore their oral health, have poorer oral hygiene habits, and experience higher rates of periodontal disease, oral cancer, and dental trauma. Men also visit dentists less frequently and compared to women seek oral treatment more often for an acute problem and less often for disease prevention. Women exhibit more positive attitudes about dental visits, greater oral health literacy, and demonstrate better oral health behaviors than men. Men disproportionately develop periodontal diseases due to a combination of biological and gender related reasons including immune system factors, hormone differences, poorer oral hygiene behaviors, and greater tobacco use. There is a male to female ratio of 2:1 for oral cancer, largely attributable to more tobacco use, heavier use of alcohol, and longer sun exposure. Minority men experience a disproportionate burden of oral health disparities because of both their gender and race/ethnic identities. In conclusion, this review identifies several differences between men and women related to oral health and highlights the need for further research to better understand these disparities and how to incorporate them into developing prevention, education and treatment strategies to improve oral health in men.

Nicotine e-vaping and cardiovascular consequences: a case series and literature review

Background

Cardiovascular toxicity as a consequence of nicotine from conventional tobacco cigarette smoking is well documented. However, little is known about the cardiovascular consequences of nicotine e-vaping. We review the literature and report a case series of three cases of major adverse cardiovascular clinical effects post nicotine e-vaping.

Case summary

Three patients with known peripheral arterial disease who switched from heavy cigarette smoking consumption to a high-intensity dose of nicotine e-vaping all developed further arterial complications within 6-30 months.

Discussion

With the recent epidemic of e-vaping in young individuals and the national outbreak of e-vaping use-associated lung injury (EVALI), the dangers of e-vaping are now coming to light. The pulmonary effects are now well described, and this paper highlights three new cases of cardiovascular toxicity associated with e-vaping. The potential role of nicotine e-vaping and the risk of coronavirus disease-2019 (COVID-19) will also be discussed.

Harmful chemicals emitted from electronic cigarettes and potential deleterious effects in the oral cavity

Use of electronic nicotine delivery systems (ENDS), such as electronic cigarettes (e-cigs), is increasing across the US population and is particularly troubling due to their adoption by adolescents, teens, and young adults. The industry’s marketing approach for these instruments of addiction has been to promote them as a safer alternative to tobacco, a behavioral choice supporting smoking cessation, and as the ‘cool’ appearance of vaping with flavored products (e.g. tutti frutti, bubble gum, and buttered popcorn etc.). Thus, there is a clear need to better document the health outcomes of e-cig use in the oral cavity of the addicted chronic user. There appears to be an array of environmental toxins in the vapors, including reactive aldehydes and carbonyls resulting from the heating elements action on fluid components, as well as from the composition of chemical flavoring agents. The chemistry of these systems shows that the released vapors from the e-cigs frequently contain levels of environmental toxins that considerably exceed federal occupational exposure limits. Additionally, the toxicants in the vapors appear to be retained in the host fluids/tissues at levels often approximating 90% of the levels in the e-cig vapors. These water-soluble reactive toxins can challenge the oral cavity constituents, potentially contributing to alterations in the autochthonous microbiome and host cells critical for maintaining oral homeostasis. This review updates the existing chemistry/environmental aspects of e-cigs, as well as providing an overview of the somewhat limited data on potential oral health effects that could occur across the lifetime of daily e-cig users.

Oral Candidiasis: A Disease of Opportunity

Oral candidiasis, commonly referred to as “thrush,” is an opportunistic fungal infection that commonly affects the oral mucosa. The main causative agent, Candida albicans, is a highly versatile commensal organism that is well adapted to its human host; however, changes in the host microenvironment can promote the transition from one of commensalism to pathogen. This transition is heavily reliant on an impressive repertoire of virulence factors, most notably cell surface adhesins, proteolytic enzymes, morphologic switching, and the development of drug resistance. In the oral cavity, the co-adhesion of C. albicans with bacteria is crucial for its persistence, and a wide range of synergistic interactions with various oral species were described to enhance colonization in the host. As a frequent colonizer of the oral mucosa, the host immune response in the oral cavity is oriented toward a more tolerogenic state and, therefore, local innate immune defenses play a central role in maintaining Candida in its commensal state. Specifically, in addition to preventing Candida adherence to epithelial cells, saliva is enriched with anti-candidal peptides, considered to be part of the host innate immunity. The T helper 17 (Th17)-type adaptive immune response is mainly involved in mucosal host defenses, controlling initial growth of Candida and inhibiting subsequent tissue invasion. Animal models, most notably the mouse model of oropharyngeal candidiasis and the rat model of denture stomatitis, are instrumental in our understanding of Candida virulence factors and the factors leading to host susceptibility to infections. Given the continuing rise in development of resistance to the limited number of traditional antifungal agents, novel therapeutic strategies are directed toward identifying bioactive compounds that target pathogenic mechanisms to prevent C. albicans transition from harmless commensal to pathogen.