- Most non-combustible nicotine products (NCNPs) like vapes, nicotine gum, sprays, and snus show no increased risk of oral health issues when compared to placebo.
- Minor irritation such as a dry mouth or ulcers is likely due to the physical mode of delivery – such as chewing or vapour inhalation – not the nicotine or other ingredients of the product.
- No NCNPs showed consistent oral side effects serious enough to put people off using them or reduce stop-smoking success.
- Despite low-quality evidence, the review supports NCNPs as safe and practical tools for reducing harm in smokers concerned about oral health.
A major global review has found that most non-combustible nicotine products (NCNPs) – including vapes, nicotine gum and sprays, and Swedish-style snus – carry little to no risk of oral health problems.
Led by the respected Center of Excellence for the Acceleration of Harm Reduction (CoEHAR) in Catania, Italy, the study is the most comprehensive evaluation to date of how NCNPs affect the mouth, gums, and oral tissues.
Published in the journal Addiction, the review analysed 36 randomised controlled trials, 21 of which were included in a network meta-analysis comparing oral side effects from various NCNPs with a placebo and standard care.
Side effects comparable to placebo
NCNPs did not appear to cause significant harm to the mouth, and in most cases, side effects were rare, mild, and comparable to the placebo.
According to the authors, oral adverse events were “commonly reported but typically of mild intensity.” These included symptoms such as dry mouth, mouth irritation, and aphthous ulcers (canker sores). The study notes that these effects are “more likely to be related to the mode of delivery rather than the nicotine content or formulation.” In other words, it’s the act of chewing gum or inhaling vapour – not the nicotine or other ingredients – that seems to trigger minor irritation for some users.
“Most of the adverse events were mild and self-limiting,” the researchers wrote. That means they tended to resolve on their own without medical intervention and were not serious enough to stop people from using the product.
Some differences were found between products. For instance, nicotine gum was more often associated with canker sores, and sprays showed slightly increased odds of mouth irritation. Snus was also linked to some irritation in certain cases. However, the effects were inconsistent across studies and generally not serious.
Crucially, the study found “no clear evidence of serious or severe oral health adverse effects,” and these side effects “were not commonly associated with discontinuation of treatment.” This suggests that NCNPs remain usable and tolerable even when mild symptoms occur.
Safer than smoking
The review reinforces the view of harm reduction advocates that smoke-free nicotine products are significantly safer for health than smoking.
Combustible tobacco is a major cause of oral disease, contributing to periodontal problems, gum recession, mucosal lesions, and oral cancers. The heat and toxic by-products from burning tobacco are known to damage soft tissues in the mouth and impair healing. NCNPs avoid combustion entirely, reducing exposure to harmful chemicals.
“For individuals who smoke and are concerned about oral health, the use of NCNPs may represent a harm reduction strategy with fewer oral health risks,” the authors wrote.
Guidance for clinicians and patients
The study also offers practical insights for clinicians and dental professionals, encouraging tailored advice based on the specific product and the needs of each patient.
People with jaw pain or dental work may not find nicotine gum comfortable, it says, while others who dislike vapour might prefer a spray or lozenge. The authors suggest that these personal differences should guide product choice, especially in clinical settings focused on smoking cessation or harm reduction.
The review suggests that dental professionals are well positioned to support smokers who want to switch to safer alternatives. Integrating harm reduction strategies into dental care may help reach more patients who are not ready to quit nicotine entirely but want to reduce their health risks.
NCNPs ‘generally safe’ for oral tissues
The authors acknowledge that many of the studies reviewed were small or relied on self-reported symptoms. As a result, the overall certainty of the evidence was rated as low. However, they said that across different trials and product types, the pattern of mild and self-limiting oral side effects was consistent.
This consistency gives confidence in the broader conclusion, which is that NCNPs are generally safe for oral tissues and do not pose the kinds of risks often associated with smoking.
