Cariogenic potential of sweet flavors in electronic-cigarette liquids

Thermoplastic starch/poly(butylene adipate-co-terephthalate) blown film with maltol and ethyl maltol preserving cake quality: Morphology and antimicrobial function

Maltol (MT) and ethyl maltol (EM) are flavoring compounds that release vapors into headspace, exerting antimicrobial effects and extending food shelf-life. This study investigated biodegradable films for packaged bakery quality. Biodegradable films (40 % polybutylene adipate terephthalate and 60 % thermoplastic starch) were produced via extrusion for films with varying MT and EM contents (1, 3, and 5 %). Scanning electron microscopy revealed smoother and more homogeneous film cross-sections with MT/EM, indicating reduced surface wrinkling. Fourier-transform infrared spectroscopy analysis suggested modified OH and CH stretching due to hydrogen bonding between TPS and EM/MT. The XRD pattern showed sharp MT crystallization, modifying crystal polymorphs of starch and PBAT. EM and MT films exhibited against Staphylococcus aureus after 24 h. Moreover, EM/MT films effectively delayed fungal growth in butter cake, inhibiting mold growth in butter cake more than twofold. These findings suggest that volatile compounds like MT/EM have promising potential for incorporation into PBAT/TPS films, creating active bakery packaging.

The Effect of New Trend Electronic Cigarettes on Dental Caries in Relation to Glucosyltransferase B and Secretory Immunoglobulin A (A Case-control Study)

Electronic cigarettes (vapes) are actively used, and their use is growing globally, especially among young people. Its spread is rapid due to the presence of unproven rumors that it is used to treat smoking addiction as it aids in smoking cessation. However, E.C has a negative impact on dental health by affecting the oral microbiome and salivary components. The goal of this study was to evaluate the impact of electronic cigarettes on dental caries in relation to glucosyltransferase B and secretory immunoglobulin in the saliva of electronic cigarette users. Ninety active males were divided into two groups: 45 electronic-cigarette smokers in addition to 45 non-electronic-cigarette smokers as a control group. An oral examination was performed on the studied groups, and decayed missing filling tooth surfaces (DMFS) were documented. Additionally, unstimulated saliva was collected to evaluate salivary glucosyltransferase B and secretory immunoglobulin A by using a sandwich enzyme-linked immune-sorbent assay (ELISA). The obtained outcomes showed that decayed, missing, and filled Surfaces values(DMFS), salivary glucosyltransferase B, and salivary secretory immunoglobulin A were greater in the study group than in control group. Additionally, a correlation between glucosyltransferase B, secretory immunoglobulin A, and DMFS was positive and significant. It was concluded that e-cigarettes may have an effect on saliva components and dental caries.

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.

Effect of different types of smoking on oral health and on cellular changes in oral mucosa

Objectives

Smoking is known to be a major risk factor for several diseases. Recently, electronic cigarettes have been introduced to the market; however, their effect on oral health has not been well studied yet. We aim to compare the effect of different types of smoking on oral health and to evaluate cytomorphological changes in oral mucosa among different types of smokers.

Study design

A total of 112 participants were recruited, conventional cigarette smokers (n = 28), electronic cigarettes smokers (n = 26), hookah smokers (n = 29) and non-smokers (n = 29). Oral examination, brush cytology and salivary flow test were performed. Cytological smears were stained and examined for cytomorphological changes. Oral symptoms, type, and frequency of smoking were obtained through questionnaires. SPSS program was used for statistical analysis.

Results

Most of the oral symptoms reported in this study were among conventional and electronic cigarettes smokers. While hookah smokers reported the least oral symptoms. Increase in DMFT and gingival index were observed among all smokers, mainly among conventional cigarettes smokers. Conventional cigarette and hookah smokers were found to have the most significant cellular changes. Electronic cigarette smokers had certain cellular changes as well.

Conclusion

All types of smoking adversely affect oral health and can induce cellular changes in the oral mucosa.

Tobacco products and oral conditions among US adults: NHANES 2017-2020

OBJECTIVES

Smoking is a major global health problem with serious systemic and oral consequences. This study aims at assessing the influence of smoking cigarettes and other types of smoked tobacco on oral conditions (OCs) using a representative sample of US adults.

METHODS

Pre-pandemic data from the National Health and Nutrition Examination Survey 2017-2020 were utilized, and 7840 adults aged ≥30 years were included in our analyses. Descriptive statistics, logistic, and negative binomial regression models were performed to assess the relationship between tobacco products and OCs including, tooth loss (TL), coronal (CC) and root caries (RC).

RESULTS

Overall, 16.29% of our sample were current cigarette smokers (CCS). TL (17.25%) and untreated RC (28.26%) were more evident among CCS. In the adjusted regression models, smoking cigarettes was associated with RC (AOR: 3.20, 95% CI; 2.02, 5.09), untreated CC (IRR: 3.08, 95% CI: 1.50, 6.31), and TL (IRR: 2.18, 95% CI: 1.64, 2.88). Regarding the type of used tobacco product in the past 5 days, cigarettes were the most common type (15.03%). The adjusted model indicated that e-cigarette smokers had the highest odds of untreated RC (AOR: 5.17, 95% CI: 2.19, 12.23) and the highest rate of TL (IRR: 2.21, 95% CI: 1.45, 3.35). Further, cigar smokers had the highest rate of teeth with untreated CC (IRR: 3.25, 95% CI: 1.46, 7.25).

CONCLUSIONS

Using tobacco products is associated with poor OCs. Dentists, being the primary oral health care providers, can play a crucial role in counseling and supporting smokers to quit as part of their routine dental examination.

E-cigarette use, perceived risks, attitudes, opinions of e-cigarette policies, and associated factors among Thai university students

INTRODUCTION

Although many countries, including Thailand, currently ban the sale of e-cigarettes, their use continues to rise, especially among young adults. Since the study of e-cigarette use among university students is limited, this study aimed to determine factors associated with e-cigarette use and explore university students' attitudes toward e-cigarettes, perceived risk, and opinion of e-cigarette policies.

METHODS

This cross-sectional study was conducted among undergraduate students using convenience sampling in a university, in central Thailand from November 2022 to February 2023. A self-administered online questionnaire was distributed to 19 faculties representing health sciences, science and technology, social and arts faculties, and the International College.

RESULTS

A total of 548 students completed the online questionnaire, and 20.4% reported ever using e-cigarettes, while 40% of e-cigarette users were unsure about the nicotine content. About 28% agreed, and 22% were unsure whether e-cigarettes could help quit smoking. Most students perceived that e-cigarettes are addictive and harmful, while about half of the participants agreed with the policy related to e-cigarettes in Thailand. Students with positive attitudes towards e-cigarettes were more likely to use e-cigarettes (AOR=1.15; 95% CI: 1.08-1.22), and those with lower perceived risk (AOR=0.89; 95% CI: 0.82-0.96) and who disagreed with e-cigarettes policy (AOR=0.93; 95% CI: 0.89-0.97) were more likely to use e-cigarettes. Personal income and having friends who use e-cigarettes were the significant predictors for e-cigarette use, while studying in the faculty of science and technology was a predictor of using e-cigarettes last month.

CONCLUSIONS

Although the perceived risk was high, about half of the students thought that e-cigarettes could help them quit smoking and were unsure or disagreed with e-cigarette banning policies. Attitude, perceived risk, policy opinions, personal income, and having friends who used e-cigarettes, were associated with e-cigarette use. Thus, correcting misunderstandings and increasing risk perceptions about e-cigarettes must be advocated among university students.

The potential health effects associated with electronic-cigarette

A good old gateway theory that electronic-cigarettes (e-cigarettes) are widely recognized as safer tobacco substitutes. In actuality, demographics also show that vaping cannibalizes smoking, the best explanation of the data is the "common liability". However, the utilization of e-cigarette products remains a controversial topic at present. Currently, there has been a widespread and substantial growth in e-cigarette use worldwide owing to their endless new flavors and customizable characteristics. Furthermore, e-cigarette has grown widespread among smokers as well as non-smokers, including adolescents and young adults. And some studies have shown that e-cigarette users are at greater risk to start using combustible cigarettes while e-cigarettes use was also observed the potential benefits to people who want to quit smoking or not. Although it is true that e-cigarettes generally contain fewer toxic substances than combustible cigarettes, this does not mean that the chemical composition in e-cigarettes aerosols poses absolutely no risks. While concerns about toxic substances in e-cigarettes and their widespread use in the population are reasonable, it is also crucial to consider that e-cigarettes have been associated with the potential for promoting smoking cessation and the clinically relevant improvements in users with smoking-related pathologies. Meanwhile, there is still short of understanding of the health impacts associated with e-cigarette use. Therefore, in this review, we discussed the health impacts of e-cigarette exposure on oral, nasal, pulmonary, cardiovascular systems and brain. We aspire for this review to change people's previous perceptions of e-cigarettes and provide them with a more balanced perspective. Additionally, we suggest appropriate adjustments on regulation and policy for e-cigarette to gain greater public health benefits.

Is there evidence that e-cigarettes promote an increased risk of dental caries?

DATA SOURCES

This study was conducted on a sample of patients who attended the dental clinic at Tufts University School of Dental Medicine, between January 1, 2019 and January 1, 2022. Ethical approval was obtained before commencing the research.

STUDY SELECTION

This cross-sectional study was carried out through an electronic search of electronic records. It includes patients aged over 16 years, both electronic cigarette (e-cigarettes) users and non-users, with recorded caries risk assessments. Patients with a history of recreational drug use or lacking a caries diagnosis were excluded. The Caries Management by Risk Assessment (CAMBRA) was utilized to indicate and classify caries risk.

DATA EXTRACTION AND SYNTHESIS

Descriptive statistics, multivariate and bivariate analyzes were used to assess the relationship between use of e-cigarettes and caries risk level. SPSS software, Version 26 (IBM) was used in the analysis with significance level set at α = 0.05.

RESULTS

Out of a total of 13,216 patients included in the research, 13,080 (99.3%) self-declared as non-users of e-cigarettes, and 136 (0.69%) were e-cigarette users. There was a statistically significant difference (P < 0.001) in caries risk levels between e-cigarette users (6.6% low, 14.3% moderate, and 79.1% high caries risk level) and control group (14.5% low, 25.9% moderate, and 59.6% high caries risk level).

CONCLUSIONS

The study provides evidence supporting the notion that e-cigarette users exhibit a high level of caries risk.

Is there a significant difference in the oral microbiome in vapers vs non-vapers?

DATA SOURCES

This study was a secondary data analysis of a parent study that was initially designed to assess saliva and exhaled breath for passive e-cigarette vapour exposure in children. The initial study collected patients using convenience sampling of the local community between July 2018 and February 2019 and ethical approval was obtained prior to commencing.

DATA EXTRACTION AND SYNTHESIS

Eligibility criteria for the parent vapers in the original study included self-reported daily use of e-cigarettes in the presence of children via the use of a questionnaire. Microbiome data for a total of 36 adults were collected and analysed in this study (18 vapers and 18 non-vapers).

RESULTS

Vapers have a distinct oral microbiome compared with non-vapers. They tend to have a higher relative abundance of Veilonella, an opportunistic pathogen that can stimulate the growth of other opportunistic pathogens. This species has also been found in carious lesions compared with healthy tooth surface.

Mechanisms of E-Cigarette Vape-Induced Epithelial Cell Damage

E-cigarette use has been reported to affect cell viability, induce DNA damage, and modulate an inflammatory response resulting in negative health consequences. Most studies focus on oral and lung disease associated with e-cigarette use. However, tissue damage can be found in the cardio-vascular system and even the bladder. While the levels of carcinogenic compounds found in e-cigarette aerosols are lower than those in conventional cigarette smoke, the toxicants generated by the heat of the vaping device may include probable human carcinogens. Furthermore, nicotine, although not a carcinogen, can be metabolized to nitrosamines. Nitrosamines are known carcinogens and have been shown to be present in the saliva of e-cig users, demonstrating the health risk of e-cigarette vaping. E-cig vape can induce DNA adducts, promoting oxidative stress and DNA damage and NF-kB-driven inflammation. Together, these processes increase the transcription of pro-inflammatory cytokines. This creates a microenvironment thought to play a key role in tumorigenesis, although it is too early to know the long-term effects of vaping. This review considers different aspects of e-cigarette-induced cellular changes, including the generation of reactive oxygen species, DNA damage, DNA repair, inflammation, and the possible tumorigenic effects.

In Vitro high-throughput toxicological assessment of E-cigarette flavors on human bronchial epithelial cells and the potential involvement of TRPA1 in cinnamon flavor-induced toxicity

Electronic cigarettes (ECs) are considered a less hazardous alternative to tobacco smoking but are not harmless. Growing concerns about the safety profiles of flavors in e-liquids underpin the need for this study. Here, we screened 53 nicotine-free flavored e-liquids (across 15 flavor categories) across a 3-point concentration range (0.25%, 0.5%, and 1% v/v) in a high-throughput fashion in human bronchial epithelial (HBEC-3KT) submerged cell cultures to identify 'toxic hits' using in vitro endpoint assays comprising cell count, cell viability, and lactate dehydrogenase (LDH). We observed significant, dose-dependent adverse effects only with cinnamon, vanilla tobacco, and hazelnut e-liquids compared to media-only and PG/VG vehicle controls. Hence, we further analyzed these three flavors for their effects on HBEC-3KT proliferation, mitochondrial health, and oxidative stress. A significant decrease in cell proliferation after 36 h was observed for each e-liquid toxic hit compared to media-only and PG/VG controls. Hazelnut (at all concentrations) and vanilla tobacco (1%) increased cytoplasmic reactive oxygen species generation compared to media-only and PG/VG controls. Conversely, all three flavors at 0.5% and 1% significantly decreased mitochondrial membrane potential compared to PG/VG and media-only controls. Chemical analysis revealed that all three flavors contained volatile organic compounds. We hypothesized that the cytotoxicity of cinnamon might be mediated via TRPA1; however, TRPA1 antagonist AP-18 (10 μM) did not mitigate these effects, and cinnamon significantly increased TRPA1 transcript levels. Therefore, pathways mediating cinnamon's cytotoxicity warrant further investigations. This study could inform public health authorities on the relative health risks assessment following exposure to EC flavor ingredients.

The Role of Electronic Cigarettes in Dental Caries: A Scoping Review

Dental caries, a predominant childhood and adolescence affliction, has numerous factors implicated in its pathogenesis. Electronic cigarettes (ECs) have recently gained popularity among the younger population. Various factors, such as the EC liquid composition and aerosols, are associated with the development of dental caries. This review explains numerous EC-related factors which may lead to dental caries. An electronic search was conducted in Medline (Pubmed), Scopus, and Embase databases to evaluate the original research investigating the role of ECs in developing dental caries. About 12 included studies in the review indicated that factors such as the composition of e-liquids and aerosols are significant in the progression of dental caries. Specifically, cariogenic sugars such as sucrose, fructose, glucose, aldehydes, and flavors such as menthol, cinnamon, and strawberry in the e-liquids contribute to dental caries. They are toxic to oral commensals such as Streptococcus gordonii, Streptococcus mitis, Streptococcus intermedius, and Streptococcus oralis and promote the proliferation of cariogenic pathogens such as Streptococcus mutans (S. mutans) which causes dental caries. However, further validation of the effects of ECs on the development of dental caries is warranted through clinical trials.

Electronic Nicotine Delivery System: End to Smoking or Just a New Fancy Cigarette

Smoking and tobacco chewing are the predominant causes of oral cancer. Tobacco is the second-most widely consumed psychoactive substance. There are numerous ways to quit smoking, of which one is electronic cigarettes (e-cigarettes). E-cigarette use is a brand-new, global trend. E-cigarette is a battery-operated device that heats a liquid to create a vapor that the consumer inhales. Several countries have acknowledged that the first step toward electronic nicotine delivery system (ENDS) management is a precise classification of ENDS within the limits of current legislation. Countries have currently categorized ENDS into four generations. People's perceptions about tobacco products have altered recently as a consequence of the advertising of ENDS. The likelihood of starting to smoke cigarettes was four times higher in adolescents who used ENDS, and the probability of quitting was reduced and often prolonged in those who used ENDS. In addition, ENDS normalizes smoking-like actions including inhaling in and exhaling smoke. Adverse marketing via geographic locations and social media platforms, as well as nicotine's irreversible effects on growing adolescent and young adult brains that predispose individuals to addicted behaviors, may be responsible for their rising appeal among teenagers. Despite this, ENDS use has risen among young individuals who have never smoked and undoubtedly face more health risks than those who do not use ENDS. The oral cavity is the first to encounter ENDS in individuals and where it initially affects the human system. As a known contributor to cardiovascular diseases, neurological conditions, and cancers, nicotine seems to be a serious cause for concern. This review provides a concise summary of the research on the components, mode of action, applications, and effects of e-cigarettes on oral as well as systemic systems.

Oral microbiome of electronic cigarette users: A cross-sectional exploration

OBJECTIVE

Electronic cigarettes have increased in popularity globally. Vaping may be associated with oral symptoms and pathologies including dental and periodontal damage, both of which have an underlying microbial etiology. The primary aim of this pilot study, therefore, was to compare the oral microbiome of vapers and non-vapers.

SUBJECTS AND METHODS

This secondary data analysis had a cross-sectional comparative descriptive design and included data for 36 adults. Bacterial 16S rRNA genes were extracted and amplified from soft tissue oral swab specimens and taxonomically classified using the Human Oral Microbiome Database.

RESULTS

Data for 18 vapers and 18 non-vapers were included in this study. Almost 56% of the vapers also smoked conventional cigarettes. Beta diversity differences were identified between vapers and non-vapers. Vapers had a significantly higher relative abundance of an unclassified species of Veillonella compared with non-vapers. Dual users had higher alpha diversity compared with exclusive vapers. Beta diversity was also associated with dual use. Multiple OTUs were identified to be associated with dual use of e-cigarettes and conventional cigarettes.

CONCLUSIONS

Vapers exhibit an altered oral microbiome. Dual use of electronic cigarettes and conventional cigarettes is associated with the presence of several known pathogenic microbes.

The mediating roles of the oral microbiome in saliva and subgingival sites between e-cigarette smoking and gingival inflammation

BACKGROUND

Electronic cigarettes (ECs) have been widely used by young individuals in the U.S. while being considered less harmful than conventional tobacco cigarettes. However, ECs have increasingly been regarded as a health risk, producing detrimental chemicals that may cause, combined with poor oral hygiene, substantial inflammation in gingival and subgingival sites. In this paper, we first report that EC smoking significantly increases the odds of gingival inflammation. Then, through mediation analysis, we seek to identify and explain the mechanism that underlies the relationship between EC smoking and gingival inflammation via the oral microbiome.

METHODS

We collected saliva and subgingival samples from 75 EC users and 75 non-users between 18 and 34 years in age and profiled their microbial compositions via 16S rRNA amplicon sequencing. We conducted raw sequence data processing, denoising and taxonomic annotations using QIIME2 based on the expanded human oral microbiome database (eHOMD). We then created functional annotations (i.e., KEGG pathways) using PICRUSt2.

RESULTS

We found significant increases in α-diversity for EC users and disparities in β-diversity between EC users and non-users. We also found significant disparities between EC users and non-users in the relative abundance of 36 microbial taxa in the saliva site and 71 microbial taxa in the subgingival site. Finally, we found that 1 microbial taxon in the saliva site and 18 microbial taxa in the subgingival site significantly mediated the effects of EC smoking on gingival inflammation. The mediators on the genus level, for example, include Actinomyces, Rothia, Neisseria, and Enterococcus in the subgingival site. In addition, we report significant disparities between EC users and non-users in the relative abundance of 71 KEGG pathways in the subgingival site.

CONCLUSIONS

These findings reveal that continued EC use can further increase microbial dysbiosis that may lead to periodontal disease. Our findings also suggest that continued surveillance for the effect of ECs on the oral microbiome and its transmission to oral diseases is needed.

IMPACT OF E-CIGARETTES ON THE ORAL HEALTH - LITERATURE REVIEW

E-cigarettes are electronic devices used to inhale aerosols generated from the vaporization of flavored liquids. Nowadays, the use of e-cigarettes has become one of the most popular alternatives to traditional smoking. The wide variety of devices and liquids makes it challenging to assess the health effects of using e-cigarettes. During the vaporization of e-liquids, toxins, carcinogens, and various other chemicals can be released and inhaled by the user. Limited data exist regarding the potential health impact of exposure to e-vapors, primarily derived from animal studies and in vitro research. The oral tissues are the first site of direct interaction with the components of the inhaled vapor. While e-cigarettes are commonly portrayed as safer alternatives to tobacco cigarettes, little is known about the short- or long-term health effects of their use. The aim of this review is to briefly present the available data regarding the impact of chemical ingredients and toxins present in e-cigarette vapors on oral cavity cells.

A comparison of the caries risk between patients who use vapes or electronic cigarettes and those who do not: A cross-sectional study

BACKGROUND

Evidence on the potential oral health effects of vaping is scarce and there are limited data on possible links to both caries and periodontal disease. The authors assessed the association between electronic cigarette (e-cigarette) or vape use and caries risk level. The Caries Management by Risk Assessment tool was used.

METHODS

A cross-sectional study of patient records was conducted; 13,098 patients who attended the dental school clinics from January 1, 2019, through January 1, 2022, were included in the study. Mann-Whitney U test and multivariable ordinal logistic regression were used to assess the relationship between use of e-cigarettes or vapes and caries risk level.

RESULTS

Data from 13,216 patients were included in the data set initially; 13,080 responded "no" when asked whether they used e-cigarettes or vapes (99.3%), and 136 responded "yes" (0.69%). There was a statistically significant difference (P < .001) in caries risk levels between the e-cigarette or vape group and the control group; 14.5%, 25.9%, and 59.6% of the control group were in the low, moderate, and high caries risk categories, respectively, and 6.6%, 14.3%, and 79.1% of the e-cigarette or vape group were in the low, moderate, and high caries risk categories, respectively.

CONCLUSIONS

In this study population, there was an association between use of e-cigarettes or vapes and caries risk level of patients; vaping patients had a higher risk of developing caries.

PRACTICAL IMPLICATIONS

Within the study limitations, it was recommended that use of e-cigarettes or vapes should not only be included in the routine dental-medical history questionnaire, but also among the risk factors that increase a patient's caries risk level.

Pulmonary effects of e-liquid flavors: a systematic review

Electronic cigarettes (ECs) are purported to be tobacco harm-reduction products whose degree of harm has been highly debated. EC use is considered less hazardous than smoking but is not expected to be harmless. Following the banning of e-liquid flavors in countries such as the US, Finland, Ukraine, and Hungary, there are growing concerns regarding the safety profile of e-liquid flavors used in ECs. While these are employed extensively in the food industry and are generally regarded as safe (GRAS) when ingested, GRAS status after inhalation is unclear. The aim of this review was to assess evidence from 38 reports on the adverse effects of flavored e-liquids on the respiratory system in both in vitro and in vivo studies published between 2006 and 2021. Data collected demonstrated greater detrimental effects in vitro with cinnamon (9 articles), strawberry (5 articles), and menthol (10 articles), flavors than other flavors. The most reported effects among these investigations were perturbations of pro-inflammatory biomarkers and enhanced cytotoxicity. There is sufficient evidence to support the toxicological impacts of diacetyl- and cinnamaldehyde-containing e-liquids following human inhalation; however, safety profiles on other flavors are elusive. The latter may result from inconsistencies between experimental approaches and uncertainties due to the contributions from other e-liquid constituents. Further, the relevance of the concentration ranges to human exposure levels is uncertain. Evidence indicates that an adequately controlled and consistent, systematic toxicological investigation of a broad spectrum of e-liquid flavors may be required at biologically relevant concentrations to better inform public health authorities on the risk assessment following exposure to EC flavor ingredients.

A Critical Review of Recent Literature on Metal Contents in E-Cigarette Aerosol

The inhalation of metallic compounds in e-cigarette (EC) aerosol emissions presents legitimate concerns of potential harms for users. We provide a critical review of laboratory studies published after 2017 on metal contents in EC aerosol, focusing on the consistency between their experimental design, real life device usage and appropriate evaluation of exposure risks. All experiments reporting levels above toxicological markers for some metals (e.g., nickel, lead, copper, manganese) exhibited the following experimental flaws: (i) high powered sub-ohm tank devices tested by means of puffing protocols whose airflows and puff volumes are conceived and appropriate for low powered devices; this testing necessarily involves overheating conditions that favor the production of toxicants and generate aerosols that are likely repellent to human users; (ii) miscalculation of exposure levels from experimental outcomes; (iii) pods and tank devices acquired months and years before the experiments, so that corrosion effects cannot be ruled out; (iv) failure to disclose important information on the characteristics of pods and tank devices, on the experimental methodology and on the resulting outcomes, thus hindering the interpretation of results and the possibility of replication. In general, low powered devices tested without these shortcomings produced metal exposure levels well below strict reference toxicological markers. We believe this review provides useful guidelines for a more objective risk assessment of EC aerosol emissions and signals the necessity to upgrade current laboratory testing standards.

Effects of Common e-Liquid Flavorants and Added Nicotine on Toxicant Formation during Vaping Analyzed by 1H NMR Spectroscopy

A broad variety of e-liquids are used by e-cigarette consumers. Additives to the e-liquid carrier solvents, propylene glycol and glycerol, often include flavorants and nicotine at various concentrations. Flavorants in general have been reported to increase toxicant formation in e-cigarette aerosols, yet there is still much that remains unknown about the effects of flavorants, nicotine, and flavorants + nicotine on harmful and potentially harmful constituents (HPHCs) when aerosolizing e-liquids. Common flavorants benzaldehyde, vanillin, benzyl alcohol, and trans-cinnamaldehyde have been identified as some of the most concentrated flavorants in some commercial e-liquids, yet there is limited information on their effects on HPHC formation. E-liquids containing flavorants + nicotine are also common, but the specific effects of flavorants + nicotine on toxicant formation remain understudied. We used 1H NMR spectroscopy to evaluate HPHCs and herein report that benzaldehyde, vanillin, benzyl alcohol, trans-cinnamaldehyde, and mixtures of these flavorants significantly increased toxicant formation produced during e-liquid aerosolization compared to unflavored e-liquids. However, e-liquids aerosolized with flavorants + nicotine decreased the HPHCs for benzaldehyde, vanillin, benzyl alcohol, and a "flavorant mixture" but increased the HPHCs for e-liquids containing trans-cinnamaldehyde compared to e-liquids with flavorants and no nicotine. We determined how nicotine affects the production of HPHCs from e-liquids with flavorant + nicotine versus flavorant, herein referred to as the "nicotine degradation factor". Benzaldehyde, vanillin, benzyl alcohol, and a "flavorant mixture" with nicotine showed lower HPHC levels, having nicotine degradation factors <1 for acetaldehyde, acrolein, and total formaldehyde. HPHC formation was most inhibited in e-liquids containing vanillin + nicotine, with a degradation factor of ∼0.5, while trans-cinnamaldehyde gave more HPHC formation when nicotine was present, with a degradation factor of ∼2.5 under the conditions studied. Thus, the effects of flavorant molecules and nicotine are complex and warrant further studies on their impacts in other e-liquid formulations as well as with more devices and heating element types.

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.

Effect of Heating on Physicochemical Property of Aerosols during Vaping

Many electronic cigarette manufacturers have offered different types of “high-end mods” that allow for controlled heating of the e-liquid. However, the controlled heating condition can drastically alter the inhaled aerosols’ physical properties and chemical substances, causing potential health risks. To investigate the contribution of heating on aerosol properties, we used four common power settings in the mods to conduct a physicochemical analysis. Our data showed that the aerosol mass and nicotine content in the aerosols increased at high power. Additionally, high power led to aerosolization of a viscous component in the e-liquid, increasing the viscosity of aerosol. However, the pH of the aerosol was constant regardless of the applied power. In addition, high-power operation made nicotine prone to oxidation, resulting in the color of the aerosol turning yellow. Lastly, we demonstrated that e-cigarette aerosol could contain various metals, including aluminum, arsenic, cadmium, chromium, copper, iron, magnesium, nickel, lead, and zinc. Even though these metal contents proportionally increased with the power setting, they remained far below the recommended exposure limits. Our finding demonstrates that the heating conditions of the e-cigarette change the physicochemical properties of the aerosols and their metal contents, thereby possibly affecting users’ oral and respiratory systems.

Electronic cigarette use enriches periodontal pathogens

The effect of electronic cigarette (e-cigarette) smoking, especially its long-term impact on oral health, is poorly understood. Here, we conducted a longitudinal clinical study with two study visits, 6 months apart, to investigate the effect of e-cigarette use on the bacterial community structure in the saliva of 101 periodontitis patients. Our data demonstrated that e-cigarette use altered the oral microbiome in periodontitis patients, enriching members of the Filifactor, Treponema, and Fusobacterium taxa. For patients at the same periodontal disease stage, cigarette smokers and e-cigarette smokers shared more similarities in their oral bacterial composition. E-cigarette smoking may have a similar potential as cigarette smoking at altering the bacterial composition of saliva over time, leading to an increase in the relative abundance of periodontal disease-associated pathogens such as Porphyromonas gingivalis and Fusobacterium nucleatum. The correlation analysis showed that certain genera, such as Dialister, Selenomonas, and Leptotrichia in the e-cigarette smoking group, were positively correlated with the levels of proinflammatory cytokines, including IFN-γ, IL-1β, and TNF-α. E-cigarette use was also associated with elevated levels of proinflammatory cytokines such as IFN-γ and TNF-α, which contribute to oral microbiome dysbiosis and advanced disease state. This article is protected by copyright. All rights reserved.

Implications of Electronic Cigarettes on the Safe Administration of Sedation and General Anesthesia in the Outpatient Dental Setting

Today the number of electronic cigarette users continues to rise as electronic cigarettes slowly, yet steadily overtake conventional cigarettes in popularity. This shift is often attributed to the misconception that electronic cigarettes are "safer" or "less dangerous" than conventional cigarettes. Recent studies have shown that electronic cigarettes are far from safe and that the inhaled agents and byproducts within vaping aerosols can have adverse effects on systemic and oral health like combustible tobacco products. The first electronic cigarettes were originally introduced as a tool for smoking cessation. However, newer iterations of electronic cigarette devices have been modified to allow the user to consume tetrahydrocannabinol (THC), the psychoactive component of cannabis, in addition to nicotine. As the popularity of these devices continues to rise, the number of patients seeking dental treatment who also consume electronic cigarettes will too. This article aims to shed light on the deleterious effects electronic cigarettes can have on systemic and oral health, as well as the special considerations for sedation and anesthesia providers treating patients who use electronic cigarettes.

A thematic analysis of smokers' and non-smokers' accounts of E-cigarettes

This study explored smokers' and non-smokers' accounts of E-cigarettes. A total of 51 UK-based participants, 20 men and 31 women, responded to open-ended questions online. Inductive thematic analysis identified that the factors that influence E-cigarette behaviour and opinion in adult smokers and non-smokers are related to social context, informative sources, practical aspects and health implications. Participants presented varying accounts of E-cigarettes, suggesting that individual narratives regarding E-cigarettes are multi-faceted. This is important information for health professionals and policy makers tasked with advising on E-cigarette use.

Use of heated tobacco products by people with chronic diseases: The 2019 JASTIS study

Heated tobacco products (HTPs) have become popular recently. People with chronic disease, such as diabetes, cardiovascular disease (CVD), chronic obstructive pulmonary disease (COPD) and cancer, should quit smoking for treatment and recurrence of tobacco-related diseases. However, they have difficulty in quitting smoking, and they may start HTPs use to quit smoking. The purpose of this study is to examine the use of HTPs in people with chronic disease. We used data from an internet study, the Japan Society and New Tobacco Internet Survey (JASTIS). We analyzed 9,008 respondents aged 15-73 years in 2019 using logistic regression. Current use of tobacco products was defined as use within the previous 30 days. Prevalence of current HTP use including dual use and dual use with cigarettes was 9.0% and 6.1% respectively in total. By disease: hypertension 10.2% and 7.4%, diabetes 15.9% and 12.3%, CVD 19.2% and 15.7%, COPD 40.5% and 33.3%, and cancer 17.5% and 11.9%. Diabetes, CVD, COPD, and cancer were positively associated with current use of HTPs (odds ratios (ORs) and 95% confidence intervals (CIs): 1.48 (1.06, 2.07), 2.29 (1.38, 3.80), 3.97(1.73, 9.11), and 3.58(1.99, 6.44), respectively) and dual use of cigarettes and HTPs (ORs and 95% CIs: 2.23 (1.61, 3.09), 3.58 (2.29, 5.60), 7.46 (3.76, 14.80), and 2.57 (1.46, 4.55), respectively) after adjusting for confounders. People with chronic disease were more likely to use HTPs and HTPs together with cigarettes. Further research on the smoking situation of HTPs in patients with chronic diseases is necessary.

Erosive potential of commonly available vapes: a cause for concern?

Objectives Relatively little is known about the erosive potential of vape products, an important consideration for dental health. This study analysed flavoured vapes with potentially low pH, including fruit and drink flavours.Methods The pH of 45 purposefully selected vapes was measured undiluted in triplicate. Serial dilution was conducted on the most erosive product to investigate if/when the erosive potential pH of 5.5 was reached. One of the most erosive samples was tested, undiluted and diluted, after four months of opening. Content analysis of the vape labels determined ingredients, place of manufacture, product usage instructions and health warnings.Results Eighty-four percent of undiluted vape samples had a pH below 5.5. Erosive potential was not predicted by the flavour, with orange and cola samples higher than anticipated (pH 3.56-6.23 and 5.04-5.63, respectively). Products that were predicted to be non-acidic such as vanilla showed considerable variation ranging from pH 4.69-5.63. Freshly opened or stored samples did not reach a non-erosive potential pH of 5.5 or above, even when diluted to represent concentrations used when vaped. Labels were not detailed enough to ascertain which ingredients were contributing to acidity or buffering capacity or to allow consumers to identify the least harmful products in terms of oral health.Conclusions Present labelling of commercially available vapes does not allow consumers to ascertain the erosive potential and possible dental damage that may be inflicted by their use. More effective labelling and/or health warnings are required to educate consumers and dental health professionals on these products.

Association between vaping and untreated caries: A cross-sectional study of National Health and Nutrition Examination Survey 2017-2018 data

BACKGROUND

With the rise in the prevalence of electronic cigarette (e-cigarette) and vaping products and the emergence of evidence indicating their cariogenic potential, it is essential to examine the association between vaping and untreated caries at a population level.

METHODS

The authors obtained data from the 2017-2018 National Health and Nutrition Examination Survey and investigated the outcome variable-untreated caries-using oral health examination data. The authors applied multiple logistic regression analyses to assess the association between untreated caries and smoking (cigarette smoking, vaping, and both) while controlling for education, race or ethnicity, income, age, sex, and time since previous dental visit.

RESULTS

A total of 4,618 participants were included in the analyses for this cross-sectional study. Participants who currently smoked e-cigarettes were more likely to have untreated caries (odds ratio, 1.69; 95% CI, 1.24 to 2.29) than those who had never smoked, when adjusted for demographic variables. Similarly, dual smokers (e-cigarette and conventional smokers) were more likely to have untreated caries compared with nondual smokers (odds ratio, 2.43; 95% CI, 1.36 to 4.36).

CONCLUSION

Both vaping and dual smoking are associated with an increased occurrence of untreated caries.

PRACTICAL IMPLICATIONS

Vaping status should be included as a part of health history questionnaires for patients. Dental professionals should be informed of the potential oral health implications of vaping and, in turn, impart this knowledge to patients.

Effects of electronic cigarette aerosol exposure on oral and systemic health

Conventional cigarette smoke harms nearly every organ of the body and is the leading cause of death in the United States and in the world. Decades of research have associated conventional cigarette smoke with several diseases and death. Heavily marketed, electronic nicotine delivery systems such as electronic cigarettes (e-cigarettes) are available in a variety of flavors and high nicotine concentrations. In 2019, a severe lung disease outbreak linked to e-cigarette use led to several deaths, which was called electronic-cigarette or vaping product use-associated lung injury (EVALI). Even though the trend of e-cigarette use among teens continues to increase, information on the effects of e-cigarette smoke on oral and overall health are still scarce. This review discusses the possible health effects due to unregulated e-cigarette use, as well as the health effects of second-hand smoke and third-hand smoke on non-smokers.

Toxicology of flavoring- and cannabis-containing e-liquids used in electronic delivery systems

Electronic cigarettes (e-cigarettes) were introduced in the United States in 2007 and by 2014 they were the most popular tobacco product amongst youth and had overtaken use of regular tobacco cigarettes. E-cigarettes are used to aerosolize a liquid (e-liquid) that the user inhales. Flavorings in e-liquids is a primary reason for youth to initiate use of e-cigarettes. Evidence is growing in the scientific literature that inhalation of some flavorings is not without risk of harm. In this review, 67 original articles (primarily cellular in vitro) on the toxicity of flavored e-liquids were identified in the PubMed and Scopus databases and evaluated critically. At least 65 individual flavoring ingredients in e-liquids or aerosols from e-cigarettes induced toxicity in the respiratory tract, cardiovascular and circulatory systems, skeletal system, and skin. Cinnamaldehyde was most frequently reported to be cytotoxic, followed by vanillin, menthol, ethyl maltol, ethyl vanillin, benzaldehyde and linalool. Additionally, modern e-cigarettes can be modified to aerosolize cannabis as dried plant material or a concentrated extract. The U.S. experienced an outbreak of lung injuries, termed e-cigarette, or vaping, product use-associated lung injury (EVALI) that began in 2019; among 2,022 hospitalized patients who had data on substance use (as of January 14, 2020), 82% reported using a delta-9-tetrahydrocannabinol (main psychoactive component in cannabis) containing e-cigarette, or vaping, product. Our literature search identified 33 articles related to EVALI. Vitamin E acetate, a diluent and thickening agent in cannabis-based products, was strongly linked to the EVALI outbreak in epidemiologic and laboratory studies; however, e-liquid chemistry is highly complex, and more than one mechanism of lung injury, ingredient, or thermal breakdown product may be responsible for toxicity. More research is needed, particularly with regard to e-cigarettes (generation, power settings, etc.), e-liquids (composition, bulk or vaped form), modeled systems (cell type, culture type, and dosimetry metrics), biological monitoring, secondhand exposures and contact with residues that contain nicotine and flavorings, and causative agents and mechanisms of EVALI toxicity.

What should every dental health professional know about electronic cigarettes?

Electronic cigarettes (E-cigarettes) have become increasingly popular around the world. Currently, dental professionals' knowledge and attitudes are varied with many clinicians unclear regarding the impact of E-cigarette products on the oral and general health of their patients. With developing social and health-related challenges, advice of dental and medical associations and other regulatory bodies on E-cigarette use is changing. Growing evidence demonstrating the risks of E-cigarette usage has prompted a review of legislation in the United Kingdom (UK), United States of America (USA), Australia and Canada to include the sale and availability of E-cigarettes, particularly those containing nicotine. Further consideration within the scientific and public health community is being given to assessing demographic usage patterns particularly uptake by non-smokers and adolescents, efficacy as a cessation tool, the impact of vapour on bystanders and direct injuries via explosions as well as emerging lung injuries. This article aims to provide a summary of the most up to date evidence relating to E-cigarette use, the latest position of dental associations and the oral health implications of E-cigarettes compared to conventional smoking. The article also aims to collate this information in order to provide dental clinicians with guidance on how to advise patients, specifically in answering common questions posed regarding E-cigarette use.

Flavorless vs. Flavored Electronic Cigarette-Generated Aerosol and E-Liquid on the Growth of Common Oral Commensal Streptococci

Introduction

Electronic cigarette (ECIG) use or vaping has become popular globally. While the question “Is vaping safer than smoking?” continues, it is becoming clearer that one of the most dangerous components of E-liquids are the flavorings. Since the oral cavity is the first anatomical site to be assaulted by ECIG aerosol, the aim of this study is to test the hypothesis that flavored ECIG aerosols or E-liquids pose a more detrimental effect on the growth of commensal oral streptococcal bacteria compared to flavorless aerosols or E-liquids.

Methods

Kirby Bauer assays and 24-h planktonic growth curves were used to compare the effects of flavorless vs. flavored (tobacco, menthol, cinnamon, strawberry and blueberry) ECIG-generated aerosols and E-liquids on the growth of four common strains of oral commensal bacteria (Streptococcus gordonii, Streptococcus intermedius, Streptococcus mitis and Streptococcus oralis).

Results

Kirby Bauer assays revealed inhibition of growth for all bacteria tested when exposed to 100% menthol, cinnamon or strawberry flavors. In contrast, 5% flavor in E-liquid had no effect. When exposed to 100 puffs of ECIG-generated aerosol ± flavors (≈ 0.05% flavor in brain heart infusion media) or an equivalent amount of E-liquid ± flavors, twenty-four hour planktonic growth curves indicated no effect on growth for all streptococci tested. Subsequent twenty-four hour planktonic growth curves testing the effects of E-liquid ± flavors (0.0625, 0.125, 0.25, 0.3125, 0.625, and 1.25% flavor in brain heart infusion media) revealed dose-dependent inhibition of growth, particularly for menthol, cinnamon and strawberry), for all bacteria tested.

Conclusion

These results support the hypothesis that flavored E-liquids are more detrimental to the growth of oral commensal bacteria than unflavored E-liquids. The streptococci tested in this study are early colonizers and part of the foundation of oral biofilms and dental plaque. Disturbances in the composition and growth of these primary colonizers is crucial to the development of a healthy dental plaque and host-bacteria interactions. E-liquids and their aerosols containing flavoring agents alter the growth of these bacteria. Such perturbations of pioneering oral communities pose a potential risk to the health of the oral cavity and, ultimately, health in general.

E-cigarettes use in the United States: reasons for use, perceptions, and effects on health

BACKGROUND

Many researchers claim electronic cigarettes (e-cigarettes) to be a breakthrough invention for tobacco users that aspires to curb their addiction to conventional cigarettes. Claimed to be safer by their promoters, these smokeless devices have become increasingly popular since their arrival on the market among users of all ages, especially adolescents. This paper investigated the trends in e-cigarette usage since the time it arrived in the United States, highlighting the highest surge that has occurred in adolescent e-cigarette use. It also aimed to understand the reasons and perceptions behind the ever-increasing use of e-cigarettes by adolescents.

MAIN BODY

With the advent of e-cigarettes and common positive perceptions regarding their use, we are at risk of reversing the years of efforts regarding tobacco control and instead advance towards a new addiction with currently unknown long-term health hazards. There is substantial data showing a significant increase of e-cigarette users in the United States, especially among adolescents. The aim of this review was to explore the reasons behind this widespread increase in the use of e-cigarettes among the teenage population in the US and also to uncover the common perceptions about these new electronic delivery systems. In addition, this review attempted to summarize health benefits and hazards associated with e-cigarette use as it crucial to have the right information among its users regarding the health effects of e-cigarette use.

CONCLUSION

E-cigarettes are more appealing than c-cigarettes for a variety of reasons, including cost, choice of different flavors, ease of accessibility, and use and impact of social media. There are also different perceptions among e-cigarette users, including both adolescents and adults. The former group may use them because of the sense of fashion associated with this novel device, and the latter might intend to quit conventional/combustible cigarettes (c-cigarettes) by switching to e-cigarettes. However, it is important to note that e-cigarettes are a recent phenomenon; therefore, there is a lack of many long-term studies that can identify future health risks associated with e-cigarette use. We need more detailed studies that focus on the long-term health effects of e-cigarette use. Moreover, with the ever-increasing usage of e-cigarettes by adolescents (10 and 19 years), it is very important that e-cigarettes be incorporated into the current tobacco-free laws and ordinances. We conclude by stating that e-cigarettes need stronger regulations to prevent youth access and use.

Electronic cigarette vapor increases Streptococcus mutans growth, adhesion, biofilm formation, and expression of the biofilm-associated genes

OBJECTIVE

It still not known whether electronic cigarettes (e-cigarettes) contribute to dental caries. This study aimed to evaluate the effect of e-cigarettes on the growth of Streptococcus mutans, the formation of biofilm, and the expression of certain virulence genes.

MATERIALS AND METHODS

Streptococcus mutans cells were exposed or not to e-cigarettes with and without nicotine or to cigarette smoke twice a day for 15 min each exposure period. The bacterial growth and the expression of glucosyltranferase, competence, and glucan-binding genes were evaluated after 24 hr. Biofilm formation was assessed after 1, 2, and 3 days. S. mutans adhesion and growth to e-cigarette exposed human teeth were assessed.

RESULTS

We observed an increase in S. mutans growth with e-cigarettes, mainly at the early culture period. This was confirmed by an increase of biofilm mass ranging from 8 ± 0.5 mg with the control to 47 ± 5 mg after six exposures to nicotine-rich e-cigarettes. S. mutans cells adhered better to e-cigarette exposed teeth. E-cigarettes increased the expression of glucosyltranferase, competence, and glucan-binding genes.

CONCLUSIONS

E-cigarettes increased the growth of S. mutans and the expression of virulent genes. E-cigarettes promoted the adhesion to, and formation of biofilms on teeth surfaces.

Electronic cigarette liquid substances propylene glycol and vegetable glycerin induce an inflammatory response in gingival epithelial cells

Information on the effects of propylene glycol (PG) and vegetable glycerin (VG) and on cytotoxicity and subsequent activation of the biological mediators is limited in periodontal diseases. This study analyzes the effect of unflavored PG/VG alone or in combination with nicotine on gingival epithelial cells. The cells were exposed to different PG/VG (± nicotine) concentrations for 24 h and cytotoxicity was evaluated by calorimetric 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromid assay. The expressions of interleukin (IL)-6, IL-8, and matrix metalloproteinases (MMPs)-9 were measured using an enzyme-linked immunosorbent assay and a western blotting. Stimulation with PG/VG mixtures reduced cell viability compared to nonexposed controls (p < 0.05). Adding PG/VG increased the levels of IL-6, IL-8, and MMP-9, and the amount of PG had more biological impact compared to the VG amount. The nicotine augmented this effect compared to its nicotine-free counterparts. In western blotting result, MMP-9 was clearly activated in almost all samples. These findings suggest that the main constituents PG/VG are cytotoxic and able to induce biological response in gingival cells in vitro. Despite being advertised as less harmful than conventional cigarettes, electronic cigarette liquid pose certain risks on periodontal cells. Awareness about the effects of electronic cigarettes on periodontal diseases must be increased.

User Perceptions of Different Electronic Cigarette Flavors on Social Media: Observational Study

BACKGROUND

The number of electronic cigarette (e-cigarette) users has been increasing rapidly in recent years, especially among youth and young adults. More e-cigarette products have become available, including e-liquids with various brands and flavors. Various e-liquid flavors have been frequently discussed by e-cigarette users on social media.

OBJECTIVE

This study aimed to examine the longitudinal prevalence of mentions of electronic cigarette liquid (e-liquid) flavors and user perceptions on social media.

METHODS

We applied a data-driven approach to analyze the trends and macro-level user sentiments of different e-cigarette flavors on social media. With data collected from web-based stores, e-liquid flavors were classified into categories in a flavor hierarchy based on their ingredients. The e-cigarette-related posts were collected from social media platforms, including Reddit and Twitter, using e-cigarette-related keywords. The temporal trend of mentions of e-liquid flavor categories was compiled using Reddit data from January 2013 to April 2019. Twitter data were analyzed using a sentiment analysis from May to August 2019 to explore the opinions of e-cigarette users toward each flavor category.

RESULTS

More than 1000 e-liquid flavors were classified into 7 major flavor categories. The fruit and sweets categories were the 2 most frequently discussed e-liquid flavors on Reddit, contributing to approximately 58% and 15%, respectively, of all flavor-related posts. We showed that mentions of the fruit flavor category had a steady overall upward trend compared with other flavor categories that did not show much change over time. Results from the sentiment analysis demonstrated that most e-liquid flavor categories had significant positive sentiments, except for the beverage and tobacco categories.

CONCLUSIONS

The most updated information about the popular e-liquid flavors mentioned on social media was investigated, which showed that the prevalence of mentions of e-liquid flavors and user perceptions on social media were different. Fruit was the most frequently discussed flavor category on social media. Our study provides valuable information for future regulation of flavored e-cigarettes.

Transfer of metals in the liquids of electronic cigarettes

Objectives: E-cigarettes are electronic devices containing a liquid that usually consists of a mixture of glycerol, propylene glycol and nicotine, with or without flavorings, in various concentrations. A vapor or aerosol is produced, and inhaled from the user, when this liquid is heated by a heating coil. This work examines the impact of three parameters (e-liquid composition, nicotine content and air flow) on the transfer of metals' from the heating coils to the e-liquids.Materials and methods: A distillation unit was used, where 20ml of an e-liquid were boiled with two commercial heating elements. Four e-liquids: 100% Propylene Glycol, 100% Glycerol, 50/50% Propylene Glycol/Glycerol, 33.3/33.3/33.3% Propylene Glycol/Glycerol/Water, three nicotine contents: 0, 0.4 and 0.8% per volume and three air flows: 0, 0.5 and 1.0 L/min, were used. The liquids were analyzed by Total Reflection X-Ray Fluorescence spectrometry to determine the final content of metals.Results and discussion: Five metals, Fe, Ni, Cu, Zn, and Pb, were found to be transferred from the heating coils to the e-liquids. The transfer of those metals increases with air flow and nicotine concentration, while e-liquid composition also has a significant impact. Glycerol enhances the transfer of metals compared to propylene glycol and their mixtures. The boiling temperature of the e-liquids increases significantly the transfer of metals in the e-liquids.Conclusions: There is a transfer of metals from the heating coils to the e-liquids. This transfer depends on the e-liquid composition and on the boiling temperature.

Electronic nicotine delivery system design and aerosol toxicants: A systematic review

BACKGROUND

Electronic nicotine delivery systems (ENDS; e-cigarettes), consisting of a battery, heating element and e-liquid, have evolved significantly with wide variation in design, components, operating powers, and chemical constituents. Generated aerosols have been reported to contain potentially toxic substances. We conducted a systematic review to assess what is known about the presence of toxicants in ENDS aerosols in order to inform how system design could mitigate risk.

METHODS

Articles reporting on or evaluating design characteristics of ENDS and aerosol constituents were included and summarized.

RESULTS

The search identified 2,305 articles, of which 92 were included after full-text review. Findings were grouped into 6 major categories of potentially harmful chemicals: carbonyls, volatile organic chemicals, trace elements, reactive oxygen species and free radicals, polycyclic aromatic hydrocarbons, and tobacco-specific nitrosamines. In general, higher concentrations of aerosol toxicants are associated with increased power or voltage. Aerosol toxicants are also associated with e-liquid flavoring agents existing as primary ingredients or as products of thermal degradation.

CONCLUSIONS

Improved ENDS design can reduce toxicant levels. Additional research is needed to develop a framework for optimizing system characteristics to minimize exposure, especially with respect to heating power and e-liquids. Both manufacturers and regulatory agencies have roles in reducing toxicants and potential health risks from ENDS.

The oral health impact of electronic cigarette use: a systematic review

Introduction: Electronic cigarette (e-cigarette) use is becoming more prevalent and is particularly popular among adolescents and conventional smokers. While the oral health sequelae of conventional smoking are well-established, the impact of e-cigarettes on oral health is still unknown. This study aims to systematically review the available research evidence on the oral health impact of e-cigarette use.Methods: This systematic review was conducted according to PRISMA guidelines and used the Effective Public Health Practice Project Quality Assessment Tool to evaluate the evidence. Three electronic databases (PubMed, Web of Science, and Embase) were systematically searched for studies including case reports. Two independent reviewers extracted data and synthesized the findings.Results: Ninety-nine articles were included in this systematic review. Analyses of the articles yielded seven categories based on symptom similarity and/or focus: mouth effects, throat effects, periodontal effects, dental effects, cytotoxic/genotoxic/oncologic effects, oral microbiome effects, and traumatic/accidental injury. The majority of mouth and throat symptoms experienced by e-cigarette users were relatively minor and temporary, with some evidence that conventional smokers who switched to e-cigarettes experienced mitigation of these symptoms. E-cigarette exposure increased the risk for deteriorating periodontal, dental and gingival health as well as changes to the oral microbiome. Extensive dental damage as a result of e-cigarette explosions were described in case reports. Components of e-cigarette vapor have known cytotoxic, genotoxic, and carcinogenic properties.Conclusions: Although switching to e-cigarettes may mitigate oral symptomatology for conventional smokers, findings from this review suggest that a wide range of oral health sequelae may be associated with e-cigarette use. Well-designed studies to investigate oral health outcomes of e-cigarette use are needed.

The Evolving Landscape of e-Cigarettes: A Systematic Review of Recent Evidence

Smoking continues to be a burden to economies and health-care systems across the world. One proposed solution to the problem has been e-cigarettes; however, because they are a relatively new product in the market, little is known about their potential health impacts. Furthermore, e-cigarettes continue to evolve at a rapid rate, making it necessary to regularly review and summarize available studies. Although e-cigarettes are marketed as a smoking cessation tool by some manufacturers, the reality is that many nonsmokers, including youth, are using them. This review focuses on two major demographic groups (smokers and nonsmokers) and evaluates the most recent data (early 2017 to mid 2019) regarding the potential health effects of e-cigarettes. We assessed peer-reviewed studies on the health impacts of e-cigarettes, with a particular focus on common questions asked by policy makers, clinicians, and scientists: (1) What are the effects of e-cigarettes compared with air/not smoking?; (2) Is there any direct evidence of harm or benefit to humans?; (3) Is there a risk from secondhand exposure?; (4) What are the risks and/or benefits of e-cigarettes compared with tobacco cigarette use?; (5) Are there risks or benefits to specific populations (eg, people with COPD or asthma, pregnant women [and their offspring])?; (6) What are the effects of flavoring chemicals?; (7) What are the effects of including nicotine in e-liquids?; (8) How often is nicotine concentration labeling incorrect?; and (9) What are the risks when e-cigarettes explode?

Is vaping better than smoking for cardiorespiratory and muscle function?

Cigarette smoking is a risk factor for respiratory disorders, cardiovascular diseases and even decrements in muscle function. Electronic cigarette use (vaping) is considered a healthier alternative to cigarette smoking and may help in smoking cessation. However, the effects of vaping are not clear yet and particularly the long-term effects of vaping are largely unknown. Some reports suggest that vaping maybe as harmful for e.g. respiratory function, as cigarette smoking. In this narrative review the effects of vaping and cigarette smoking on respiratory, cardiovascular and muscle function are compared. Overall, vaping has been found to cause similar effects as smoking on lung function and cardiovascular function. Future studies are needed to clarify the severity of smoking- and vaping-induced decrements on muscle function.

Health Effects Associated With Electronic Cigarette Use: Automated Mining of Online Forums

Background

Our previous infodemiological study was performed by manually mining health-effect data associated with electronic cigarettes (ECs) from online forums. Manual mining is time consuming and limits the number of posts that can be retrieved.

Objective

Our goal in this study was to automatically extract and analyze a large number (>41,000) of online forum posts related to the health effects associated with EC use between 2008 and 2015.

Methods

Data were annotated with medical concepts from the Unified Medical Language System using a modified version of the MetaMap tool. Of over 1.4 million posts, 41,216 were used to analyze symptoms (undiagnosed conditions) and disorders (physician-diagnosed terminology) associated with EC use. For each post, sentiment (positive, negative, and neutral) was also assigned.

Results

Symptom and disorder data were categorized into 12 organ systems or anatomical regions. Most posts on symptoms and disorders contained negative sentiment, and affected systems were similar across all years. Health effects were reported most often in the neurological, mouth and throat, and respiratory systems. The most frequently reported symptoms and disorders were headache (n=939), coughing (n=852), malaise (n=468), asthma (n=916), dehydration (n=803), and pharyngitis (n=565). In addition, users often reported linked symptoms (eg, coughing and headache).

Conclusions

Online forums are a valuable repository of data that can be used to identify positive and negative health effects associated with EC use. By automating extraction of online information, we obtained more data than in our prior study, identified new symptoms and disorders associated with EC use, determined which systems are most frequently adversely affected, identified specific symptoms and disorders most commonly reported, and tracked health effects over 7 years.