As headlines concerning e-cigarettes continue to dominate the news, Dr Richard Holliday and Professor Elaine McColl talk through the impact of vaping on the oral health of patients.
Over the last few months there has been a flurry of media stories about vaping and oral health – some even made the national newspapers and their letter pages. These articles have made several claims such as vaping causes ‘your gums falling off and teeth dropping out’. Some have even implied that users are better going back to tobacco smoking.
In this article we plan to give you a brief overview of the evidence base on this topic. This is not intended to be a comprehensive systematic review. Rather it is designed as an easy-to-read summary of the current position with reflections on where we go next and how you can get involved.
Spoiler alert: as with many things in healthcare the answer to this question is nuanced, risk-based and with caveats. The reality is not headline grabbing. But as healthcare professionals we have a duty to understand complex situations and relay that information reliably to our patients.
The clinical context of vaping
A fundamental point to make is that there are two quite different clinical situations that we need to consider with regards to vaping.
The first situation is an individual who smokes tobacco and is using e-cigarettes to cut down or quit (or someone who has recently quit smoking but still using an e-cigarette). The evidence base is relatively strong for e-cigarettes as a smoking cessation aid. A Cochrane review is updated monthly on this topic and currently includes data from 61 studies, including 34 randomised controlled trials.
The evidence finds e-cigarettes are an effective cessation aid, better than nicotine replacement therapy. The use of e-cigarettes in this way is supported by many organisations such as the NHS, NICE, UK Health Security Agency (formerly Public Health England) and the Royal College of Physicians.
For pregnant women the advice from the Royal College of Obstetricians and Gynaecologists and the Royal College of Midwives is to use traditional nicotine replacement therapy (NRT). For example, patches and gum but if they find e-cigarettes helpful, it is far safer than smoking.
The second situation is an individual (perhaps a young person) who has not previously smoked, but starts regularly using an e-cigarette. This situation has come to our particular attention over the last year. This is due to the surge in popularity of disposable e-cigarettes (elf bars, geek bars) among young people who are vaping. But also due to increased promotion on social media platforms.
There is much concern about this from both parents and public health professionals. Although it appears they are regularly flouted, the UK has regulations in place for these products. It is illegal to sell e-cigarettes to under 18s, with retailers potentially facing a £2,500 fine. Proxy sales (ie buying for someone underage) are also illegal.
Let us focus on oral health. What are the potential oral health implications of e-cigarette use?
Introducing any substance into the oral cavity on a regular basis will have effects on this complex environment. Whether these are negative or positive, or will lead to disease development or progression, it will take years of research and in some cases may never be fully known.
For the first situation (smokers/ex-smokers), we have a disease-rich starting position. Tobacco smoke contains an almost uniquely toxic cocktail of chemicals, which cause an array of general and oral health diseases. Quitting smoking will lead to major improvements to oral health and reduction in risk of disease development or progression eg oral cancer risk reduces.
From a periodontal perspective, when smokers quit they often see a short-term increase in gingival bleeding. This happens as the effects of tobacco smoke on the gingival tissues are removed.
For those with periodontitis we know that their response to periodontal therapy is improved. E-cigarette aerosol does not contain tar, carbon monoxide or high doses of known carcinogens (sometimes low doses of carcinogens have been identified).
Any negative oral health impacts from e-cigarette use are likely to be small and of relatively minor consequence to the substantial beneficial oral health changes from stopping smoking. This is supported by a small number of clinical studies. These have followed smokers as they quit smoking with the use of an e-cigarette (‘switching’). These studies all see an improvement in oral health.
The advice on longer-term e-cigarette use in this group is a balance between the risk of relapse to smoking and the potential general and oral health effects from long term e-cigarette use. After any quit attempt the risk of relapse to smoking is large (75% of smokers relapse between four weeks and 12 months after an initial quit attempt). The potential general and oral health consequences from e-cigarette use are relatively minor on the evidence we have to date.
Hence, the current NICE guidance is that users should use e-cigarettes for ‘for long enough to prevent a return to smoking’. They should stop using them ‘when they are ready to do so’. This will be a very individual decision based on the person’s circumstances.
In the second situation (a young person who is a ‘never smoker’), we generally have a healthy starting position. It is likely we will see impacts on the oral health from long term e-cigarette use.
Irregular or short-term use are unlikely to lead to any measurable intraoral effects. But with the addictive properties of nicotine there is a risk users become addicted and long-term users. There are three main areas of potential impacts on oral health that e-cigarettes might have:
1. Periodontal health
This is the area that most of the studies have focused on so far. They show conflicting findings and have generally used weaker study designs. Several studies show e-cigarette users’ periodontal health to be comparable to non-users while others show some aspects are measurably worse. It is worth mentioning here that nicotine itself is not a risk factor for periodontal disease.
This was a common misrepresentation in the recent media stories (eg whole tobacco smoke and nicotine are often incorrectly used interchangeably). A number of studies have looked at the oral microbiome and reported that e-cigarette users have a distinct make up of oral bacteria. This is made up of several pathogenic species.
Further work is needed in this area to follow these users over time and to validate biochemically that these users were not also smoking tobacco (which data from one study suggests they were).
There is very little clinical evidence for this. E-cigarettes do not usually contain sugars as they have burning temperatures lower than the e-cigarette heating element. Devices would become clogged quickly. Artificial sweeteners such as Sucralose are used instead.
Natural ingredients (which could contain sugars) are not permitted under EU regulations. However, caries risk is an important area to watch. Oral dryness is one of the most commonly reported side effects from e-cigarette use. It been suggested that this is due to the water-binding effects of the ingredient propylene glycol. It could be a route into higher caries risk.
3. Oral cancer
Tobacco smoke is full of carcinogens from the tar and the burning process. E-cigarettes avoid both of these. Nicotine is not a carcinogen (supported by the use of oral nicotine products for 30-40 years). Hence, this is not currently an area of concern.
For a comprehensive review of the oral biology related to vaping we would point readers towards this recent review in the Journal of Dental Research.
In summary, e-cigarettes have good evidence to support them as an effective smoking cessation aid for tobacco smokers. Smokers can expect to see substantial improvements in their oral health if they fully switch to an e-cigarette.
Longer-term use is a balanced judgement between smoking relapse prevention against the small risk of any detrimental effects from the e-cigarettes themselves.
Non-smokers taking up e-cigarettes will, however, be exposing themselves to unnecessary risks. The oral health consequences in this group are still poorly studied. We need more well-conducted research.
In many areas of oral health advice, the messaging we give our patients as dental professionals should be tailored to the individual in front of us. The situation is no different with e-cigarettes.
Research is ongoing in this area, in the form of a national multi-centre clinical trial funded by the National Institute for Health and Social Care Research (NIHR). The trial is currently looking for dental teams to take part.
This is a great opportunity to take part in an exciting piece of research. You can help to build the evidence base on this important topic.
Please find more information and register your interest here: www.forms.ncl.ac.uk/view.php?id=9058673. We are particularly looking for dental professionals (especially DCPs!) near Edinburgh, Dundee, Newcastle, Birmingham and Plymouth (our hubs in Sheffield and Glasgow are currently at capacity).
Dr Richard Holliday is a senior lecturer, honorary consultant in restorative dentistry and specialist in periodontics at Newcastle University. Professor Elaine McColl is a professor of Health Services Research.