- Vaping and other smoke-free nicotine products cause less oral harm than smoking
- Combustible cigarette users showed the worst results across four oral health categories
- Vapers landed between smokers and never-users on most measures
- More research is needed, but early signs suggest harm reduction benefits
Vaping and other non-combustible nicotine products are much gentler on gums and teeth than smoking, according to a large review of 52 human studies.
The review, led by German researchers and published in the Harm Reduction Journal, examined how vaping, heated tobacco, and nicotine pouches affect oral health compared to smoking and not using nicotine at all.
While quitting completely remains the healthiest option, the evidence shows vaping is a lower-risk alternative to cigarettes when it comes to mouth health.
The researchers looked at nearly 200 findings from human studies published up to August 2024.
These findings were grouped into four main areas: precancerous changes, signs of inflammation like bleeding gums, everyday dental issues such as plaque and bone loss, and changes in the mouth’s bacterial balance (the microbiome).
Smokers’ oral health significantly worse
To compare the risks, they used a scoring system where higher numbers meant worse outcomes than those seen in non-users. On average, vapers scored 0.37 across all measures.
When directly compared to cigarette smokers, the results favoured vaping. Smokers scored -0.19, meaning their oral health was significantly worse. The researchers concluded that vaping causes fewer problems in the mouth than smoking, though more than seen in people who use no nicotine at all.
“Individuals who engaged in vaping exhibited significantly reduced negative effects in the oral cavity compared to those using combustible cigarettes,” the authors wrote.
Smokers had higher inflammation markers
Inflammation markers told a similar story. In 76 comparisons between vapers and people who never used nicotine, vapers were more likely to have swollen or bleeding gums. But in 69 comparisons between vapers and smokers, the smoking group consistently had worse outcomes.
Routine dental problems, such as plaque build-up and gum recession, showed the clearest differences. In a six-month study, smokers saw their gum health get worse over time – bone loss and the depth of gum pockets increased. Among vapers, these same issues remained stable, showing no decline over the same period.
The bacteria living in participants’ mouths were also affected. Changes were not as disruptive among vapers as those seen in smokers, although they were larger and more frequent than in people who never used nicotine.
In one six-month study, each group developed a unique bacterial pattern. The healthiest group was non-users, followed by vapers, with smokers showing the most disruption.
Vaping a safer option
While scientists caution that upsetting this bacterial balance may raise the risk of gum disease, infection, or even oral cancer, the evidence still pointed to vaping as a safer option than smoking.
The authors stressed that this was a qualitative review, not a traditional number-based meta-analysis. It included studies that varied widely in size, from just 30 people to more than a million, and differed in design, length, and testing methods. That means the results are more about general trends than precise risk figures.
Another issue is dual use. In the U.S., nearly 30 per cent of adults who vape also smoke cigarettes. Many of the studies relied on self-reported smoking status or short-term breath tests, which may not always catch occasional smoking. As a result, the apparent harm from vaping could be slightly overstated if some smokers were misclassified.
Vaping ‘an effective harm reduction tool’
Although vaping has not been around long enough to track its long-term effects, researchers noted that short and medium-term signs are beginning to pile up.
In one clinic, gum health improved fastest in people who never used nicotine. Vapers showed some improvement, while smokers improved the least.
Other ingredients in vape liquid – like propylene glycol and vegetable glycerin – may dry the mouth, encouraging plaque buildup. And nicotine, even in lower doses, narrows blood vessels and can hide early signs of gum disease by reducing bleeding.
“There is a need for further research into the long-term effects of these products… as well as the underlying biological mechanisms,” the authors wrote.
The review strengthens the case for vaping as a harm reduction tool. While quitting nicotine altogether remains the best choice for oral health, switching from smoking to vaping or using nicotine pouches is proving to be much safer.
