E-cigarettes deliver a range of chemicals to the mouth, including nicotine and low doses of hundreds of other chemicals that have the potential to cause harm (see Section 18.5). Chemicals from e-cigarettes have the potential to trigger inflammation, oxidative damage and cancer in the mouth.
Cigarettes and other tobacco products are a cause of dental pathologies such as periodontitis, tooth decay (caries) and cavities as described in Section 3.11 Dental diseases. These conditions take many years to develop. E-cigarette use is a fairly new phenomenon, and while evidence of potential effects is currently limited, there is concern that this habit may also lead to poor oral and dental outcomes for long-term users.
Estimating the effects of e-cigarette use on oral health using the current research is challenging. Many studies have been published that claim an effect. However, most of these are small, cross-sectional studies using convenience sampling. These studies may be useful for informing research areas for future priority, but cannot be used to claim cause and effect, or generalised (used to make an estimate of how common a condition is in the general population of e-cigarette users).
Two recent studies of high quality, however, have provided support for long-term effects of e-cigarette use on oral health. These longitudinal studies have found periodontitis,1 bone loss around teeth, and tooth extraction2 to be more common amongst e-cigarette users than non-users/non-smokers, after adjusting for likely confounding factors.
Periodontitis is an advanced-stage gum disease that usually results from untreated gingivitis (inflammation of the gums resulting from plaque on the teeth and gums). Periodontitis is characterised by inflammation and damage to the gums, ligaments and bones. It can lead to the development of abscesses in soft tissue and bone, a greater risk of decay of the exposed root surfaces of the tooth, loose teeth and tooth loss. Smoking tobacco is a cause of periodontitis. The exact mechanism/s by which smoking does this are unknown, but nicotine is thought to be involved (see Section 3.11.1).
Numerous studies have examined whether e-cigarette use is associated with gum diseases such as periodontitis. A large cohort study has compared the self-reported incidence of new periodontitis in regular e-cigarette users compared to people who did not smoke or use e-cigarettes.1 After adjusting for smoking history and other confounding factors, e-cigarette users had a higher chance of being diagnosed with gum disease, periodontal disease and of loss of bone around the teeth compared to non-users over the two year course of the study.1
A second longitudinal cohort study showed that exclusive nicotine e-cigarette users were more likely than never tobacco users to have suffer tooth extraction and bone loss around teeth,2 consistent with an increase in periodontitis proposed above.
Numerous case-control and cross-sectional studies indicate that e-cigarette users have a greater susceptibility than non-users (who are also non-smokers) to deleterious alterations to their oral cavities.3, 4 These include the clinical parameters of periodontal disease such as bleeding depth and clinical attachment loss. However, there is some evidence that bleeding upon probing (a clinical parameter of periodontitis) is lower in e-cigarette users than non-users. Higher plaque index, bone loss and sub-clinical markers of inflammation have been found to be more common in e-cigarette users. One study found that e-cigarette users without clinical periodontitis had signs of inflammation and other changes similar to those with periodontitis.5 These results, are preliminary and need confirming in large prospective cohort studies. Issues with the current studies include a reliance on self-reporting and failure to account for potential confounders such as age, general health status and prior smoking.4
184.108.40.206 Dental caries (tooth decay), enamel effects and the oral microbiome
Teeth are protected by a hard, mineral covering called enamel. Acids from food or oral bacteria can damage the enamel, leading to decay. Tooth decay (dental caries) is the deterioration of teeth, both the enamel and underneath structures, which leads to cavities if untreated. Communities (biofilms) of microorganisms such as bacteria that produce acids are a cause of tooth decay.6
There are no longitudinal studies on the effects of e-cigarette use on enamel, tooth decay and cavities. One cross-sectional study found that those who currently used e-cigarettes were more likely to have untreated caries than never smokers when adjusted for demographic variables and former smoking.7 Whether nicotine or non-nicotine e-cigarettes were used was not examined. Prospective studies are required before causation of tooth decay by e-cigarette use can be inferred.
It is feasible that some of the effects of e-cigarette use on the mouth may lead to tooth decay. There is some evidence, albeit preliminary and inconsistent, that e-cigarette use changes the oral microbiome— the range of bacterial species living in the mouth. E-cigarette emissions contain some sugars which may affect bacterial growth, acids such as acetic acid which may directly act on tooth enamel, as well such as aldehydes and other chemicals capable of causing cellular damage such as inflammation and oxidative stress (see Section 18.5). Emissions from some e-cigarettes have a low pH,8 lower than the critical level at which enamel starts to demineralise, which is predicted to be pH 5.5.9 However, it cannot be assumed that these emissions would critically lower the pH in the mouth, given the presence of buffers in the saliva. These factors may be part of an underlying biological mechanism underlying the proposed e-cigarette promotion of dental caries, however there is sparse evidence from human studies to determine whether this is the case.
The types of bacteria and other micro-organisms living in the mouth (the oral microbiome) have a role to play in tooth decay. Commensal bacteria— those that cause no harm and may even provide benefit— are known to dominate the oral microbiome of people with good oral health. Other types of bacteria are found in the mouths of people with tooth decay and are believed to be a cause of this condition.6
Four studies have examined the potential for e-cigarette emissions to affect the human oral microbiome. While there are some consistencies between these studies, the oral microbiomes of e-cigarette users, in general, remain poorly characterised. In one cross-sectional study of the oral bacterial biome, numerous genera of bacteria, including Veillonella were found at higher levels in e-cigarette users compared to smokers and never smokers.5 A similar study from the same year identified some distinct bacterial communities in the mouths of e-cigarette users compared to non-smokers and smokers.10 In another study, nicotine e-cigarette users had higher levels of Veillonella, Haemophilus and Staphylococcus aureus bacteria.11 A small pilot study of the oral microbiome also found differences in varieties of Veillonella for nicotine e-cigarette users, but only in a subset of Veillonella species.12 Inconsistencies between these studies may have arisen due to their small samples, use of convenience sampling (rather than a representative sample of e-cigarette users), and from differences in the technologies used to process samples. Further research is needed to determine whether changes to the oral microbiome in e-cigarette users are actually pathogenic.
Laboratory studies of bacterial growth indicated that e-cigarette emissions promoted the biofilm formation (growth in a structured colony) of Streptococcus mutans, which is known for causing dental caries.13, 14 Increased biofilm formation of S. mutans was observed after exposure to emissions from e-cigarettes containing nicotine, nicotine-free, nicotine-free with menthol and nicotine with menthol.14 Nicotine and menthol were therefore not necessary for the effects of e-cigarette emissions on this bacteria. While it is possible that differences in bacterial growth may be one mechanism behind a proposed increase in dental caries from e-cigarette use, this remains to be tested in definitive studies.
220.127.116.11 Oral infections
E-cigarette use has the potential to increase the risk of oral infection. Possible mechanisms are pathogen transmission during sharing of devices, and the effects of chemicals in e-cigarettes on the oral cavity, such as impairing immune defences and causing mouth dryness. Chemicals from e-cigarettes might also act directly on microbes found in the mouth. However, there are currently no high-quality longitudinal studies demonstrating increased infection with e-cigarette use or presence of the possible biological mechanisms described above. The studies described below are cross-sectional (so cause and effect cannot be inferred) and often used small convenience samples rather than representative samples (so prevalence or incidence cannot be inferred).
Preliminary studies indicate that the presence of some types of bacteria in the oral cavity, such as the Veillonella genus, is more common in e-cigarette users, as described above in Section 18.104.22.168.5, 11, 12 This bacteria is a common part of the oral flora but can be associated with diseases such as periodontitis and dental caries.
Human papilloma virus (HPV) infection, particularly HPV-16 variant, can cause oral and cervical cancer. A cross-sectional study examined HPV-16 infection risk using data from over 9,000 people in the US from the National Health and Nutrition Examination Survey (NHANES).15 E-cigarette users were almost three times more likely to have oral HPV-16 than non-users, once other factors were taken into account. The sample in this survey was representative of the US population, however the cross-sectional nature of the study means that causation cannot be inferred.15 This study did not report on whether participants used e-cigarettes containing nicotine.
Two small cross-sectional studies have indicated that oral infection with the yeast Candida albicans is more common in e-cigarette users than non-smokers/non-users.4, 16, 17 Before causation can be concluded, these results will need to be confirmed in longitudinal studies with adjustment for potential confounding factors such as prior smoking.
22.214.171.124 Oral lesions and carcinogenic effects
Oral lesions are damaged or diseased areas of the lining of the mouth. Oral lesions can arise for a variety of reasons, such as biting, infections, pre-cancerous conditions, oral cancer or inflammatory conditions.18
One preliminary study indicated that people who switch from conventional cigarettes to e-cigarettes were more likely to have oral lesions such as hairy tongue, nicotinic stomatitis and angular cheilitis.16 Conversely, no increase in oral lesions was reported for exclusive e-cigarette users, compared to never tobacco users in the longitudinal cohort study known as Population Assessment of Tobacco and Health Study.2
126.96.36.199 Dental trauma
Dental trauma refers to damage to teeth that includes chipping, cracking, fracturing, loosening or moving to a different position. There is strong evidence that oral and dental trauma can result from exploding e-cigarette devices. Surveillance reports and case series have documented many incidences of explosions causing burns and injuries to the mouth from projectiles as a result of explosions.19, 20 Burns and injuries from explosions are discussed further in Section 18.4.1.
It is also feasible that the regular use of devices held near or in the mouth could increase the risk of accidents leading to dental trauma. A large, cross-sectional study has indicated that school children who regularly use e-cigarettes were more likely to ‘tongue and/or inside-cheek pain’ and a ‘cracked or broken tooth’ than never users of e-cigarettes.21 As a cross-sectional study, caution must be used for inferring cause and effect. However, numerous potential confounding factors, such as conventional cigarette smoking, were accounted for in this study. Longitudinal studies are required to support these findings.
188.8.131.52 Effect of cigarette use on dental or oral treatments
Peri-implantitis is a post-treatment complication of dental implants, characterised by soft tissue inflammation and bone loss surrounding the implant. The presence of plaque contributes to peri-implantitis.
One longitudinal study has shown that e-cigarette users were more likely to exhibit some clinical parameters of peri-implantitis by one year after treatment compared to non-users/non-smokers. However, this study was not able to adjust for potential confounding factors such as age and prior smoking.22 Further studies are necessary to assess the effects of e-cigarette use on peri-implantitis and other dental procedures.
Relevant news and research
For recent news items and research on this topic, click here. ( Last updated January 2023)
1. Atuegwu NC, Perez MF, Oncken C, Thacker S, Mead EL, et al. Association between regular electronic nicotine product use and self-reported periodontal disease status: Population Assessment of Tobacco and Health Survey. International Journal of Environmental Research and Public Health, 2019; 16(7). Available from: https://www.ncbi.nlm.nih.gov/pubmed/30970567
2. Chaffee BW, Lauten K, Sharma E, Everard CD, Duffy K, et al. Oral health in the Population Assessment of Tobacco and Health Study. Journal of Dental Research, 2022; 101(9):1046-54. Available from: https://pubmed.ncbi.nlm.nih.gov/35403466/
3. Ralho A, Coelho A, Ribeiro M, Paula A, Amaro I, et al. Effects of electronic cigarettes on oral cavity: A systematic review. Journal of Evidence-Based Dental Practice, 2019; 19(4):101318. Available from: https://www.ncbi.nlm.nih.gov/pubmed/31843181
4. Yang I, Sandeep S, and Rodriguez J. The oral health impact of electronic cigarette use: a systematic review. Critical Reviews in Toxicology, 2020:1-30. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32043402
5. Ganesan SM, Dabdoub SM, Nagaraja HN, Scott ML, Pamulapati S, et al. Adverse effects of electronic cigarettes on the disease-naive oral microbiome. Science Advances, 2020; 6(22):eaaz0108. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32518820
6. Mosaddad SA, Tahmasebi E, Yazdanian A, Rezvani MB, Seifalian A, et al. Oral microbial biofilms: an update. European Journal of Clinical Microbiology & Infectious Diseases, 2019; 38(11):2005-19. Available from: https://pubmed.ncbi.nlm.nih.gov/31372904/
7. Vemulapalli A, Mandapati SR, Kotha A, and Aryal S. Association between vaping and untreated caries: A cross-sectional study of National Health and Nutrition Examination Survey 2017-2018 data. Journal of the American Dental Association, 2021. Available from: https://www.ncbi.nlm.nih.gov/pubmed/34274068
8. Fairchild R and Setarehnejad A. Erosive potential of commonly available vapes: a cause for concern? British Dental Journal, 2021; 231(8):487-91. Available from: https://www.ncbi.nlm.nih.gov/pubmed/34686816
9. Lussi A, Schlueter N, Rakhmatullina E, and Ganss C. Dental erosion--an overview with emphasis on chemical and histopathological aspects. Caries Research, 2011; 45 Suppl 1:2-12. Available from: https://pubmed.ncbi.nlm.nih.gov/21625128/
10. Pushalkar S, Paul B, Li Q, Yang J, Vasconcelos R, et al. Electronic cigarette aerosol modulates the oral microbiome and increases risk of infection. iScience, 2020:100884. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32105635
11. Chopyk J, Bojanowski CM, Shin J, Moshensky A, Fuentes AL, et al. Compositional differences in the oral microbiome of e-cigarette users. Frontiers in Microbiology, 2021; 12:599664. Available from: https://www.ncbi.nlm.nih.gov/pubmed/34135868
12. Yang I, Rodriguez J, Young Wright C, and Hu YJ. Oral microbiome of electronic cigarette users: A cross-sectional exploration. Oral Diseases, 2022. Available from: https://www.ncbi.nlm.nih.gov/pubmed/35285123
13. Kim SA, Smith S, Beauchamp C, Song Y, Chiang M, et al. Cariogenic potential of sweet flavors in electronic-cigarette liquids. PLoS One, 2018; 13(9):e0203717. Available from: https://www.ncbi.nlm.nih.gov/pubmed/30192874
14. Catala-Valentin A, Bernard JN, Caldwell M, Maxson J, Moore SD, et al. E-cigarette aerosol exposure favors the growth and colonization of oral streptococcus mutans compared to commensal streptococci. Microbiology Spectrum, 2022; 10(2):e0242121. Available from: https://www.ncbi.nlm.nih.gov/pubmed/35377225
15. Hong YR and Mainous AG, 3rd. Electronic cigarette use and oral human papillomavirus infection among US adult population: analysis of 2013-2016 NHANES. Journal of General Internal Medicine, 2020. Available from: https://www.ncbi.nlm.nih.gov/pubmed/32514893
16. Bardellini E, Amadori F, Conti G, and Majorana A. Oral mucosal lesions in electronic cigarettes consumers versus former smokers. Acta Odontologica Scandinavica, 2017:1-3. Available from: https://www.ncbi.nlm.nih.gov/pubmed/29161938
17. Mokeem SA, Abduljabbar T, Al-Kheraif AA, Alasqah MN, Michelogiannakis D, et al. Oral Candida carriage among cigarette- and waterpipe-smokers, and electronic-cigarette users. Oral Diseases, 2018. Available from: https://www.ncbi.nlm.nih.gov/pubmed/29800492
18. Wong T, Yap T, and Wiesenfeld D. Common benign and malignant oral mucosal disease. Australian journal of general practice, 2020; 49(9). Available from: https://www1.racgp.org.au/ajgp/2020/september/common-benign-and-malignant-oral-mucosal-disease
19. Banks E, Yazidjoglou A, Brown S, Nguyen M, Martin M, et al. Electronic cigarettes and health outcomes: systematic review of global evidence. Report for the Australian Department of Health. Canberra: National Centre for Epidemiology and Population Health, 2022. Available from: https://nceph.anu.edu.au/research/projects/health-impacts-electronic-cigarettes#health_outcomes.
20. National Academies of Sciences, Engineering, and Medicine releases FDA-commissioned report on the potential public health consequences of e-cigarettes. 2018. Available from: https://www.fda.gov/NewsEvents/Newsroom/FDAInBrief/ucm593407.htm?utm_source=Eloqua&utm_medium=email&utm_term=stratcomms&utm_content=nasreport&utm_campaign=CTP%20News%3A%20NAS%20Report%20-%2012318
21. Cho JH. The association between electronic-cigarette use and self-reported oral symptoms including cracked or broken teeth and tongue and/or inside-cheek pain among adolescents: A cross-sectional study. PLoS One, 2017; 12(7):e0180506. Available from: https://www.ncbi.nlm.nih.gov/pubmed/28700729
22. AlJasser R, Zahid M, AlSarhan M, AlOtaibi D, and AlOraini S. The effect of conventional versus electronic cigarette use on treatment outcomes of peri-implant disease. BMC Oral Health, 2021; 21(1):480. Available from: https://www.ncbi.nlm.nih.gov/pubmed/34579704