How do smoking and vaping affect periodontal health?

It is undeniable that both smoking and vaping have negative effects on oral health. But the two forms of consuming nicotine impact oral tissues in different ways, which has implications in terms of the damage that they cause.

In conventional cigarettes, tobacco burns at high temperatures (600-800°C) releasing smoke, ash, and more than 6,000 different chemicals including tar and carbon monoxide. The increasingly popular heated-tobacco products (HTP), which release a vapour from heating tobacco and involve lower temperatures (around 350°C degrees), release lower levels of harmful substances because they avoid combustion.

In vaping, using so-called e-cigarettes, a coil heats a liquid to release and aerosol or vapour and the temperatures involved are lower still (100 to 250°C). While this may be far less harmful than smoke in terms of chemicals, more research is needed on the precise nature of the chemicals released and their effects.

There are two main groups of people who vape: adults who want to quit smoking and younger people who want to consume nicotine but not to smoke. For the first group, there is robust evidence that vaping can help with smoking cessation and some evidence that it works better than other nicotine-replacement forms or pharmacological therapies.

For the second group, there are fears that vaping can be a gateway to smoking. There is some evidence that youth vaping is associated with the later take-up of cigarette smoking, but whether this is causal or not is difficult to establish: people who vape are different from those who do not vape, and they may be more likely to start smoking anyway.

There have been projections about the expected benefits in life expectancy if every cigarette smoker switched to e-cigarettes or alternative tobacco products, and it would be reasonable to assume that there would also be benefits in dental outcomes. But we cannot yet be sure of that.

How smoking and vaping affect oral health

Smoking is by far the most important behavioural/environmental risk factor for periodontal disease. It took the profession a long time to realize just how important a risk factor smoking actually is, perhaps because it was so focused on plaque and brushing that it ignored the importance of other host factors. But it is now clear that cigarette smoking leads to a much higher incidence of periodontitis and ultimately to tooth loss. There is very robust evidence from large cohorts showing both dose response and the benefit of cessation.

While we know that there are far fewer toxicants in what is inhaled from e-cigarettes (or HTPs), it is way too early to say anything definitive in terms of the potential harms because there is not yet sufficient evidence. This is largely because these products have not been around for long enough to exert a harmful effect on periodontal tissues. With periodontitis—and even more so with tooth loss—there are long latency periods before harmful effects appear.

Warning signs from smoking or vaping

The first warning signs a dentist or periodontist may see in relation to smoking or vaping include receding gums, worsened periodontal disease, tooth mobility, discolouration, and a dry mouth from reduced saliva. Lack of bleeding is another potential warning sign. On various molecular levels and mechanisms, we see is less bleeding or less swelling in the gums of smokers. This is dose-dependent: in light or moderate smokers, we do not see the extent or the effects that we see in heavy smokers.

There is evidence that e-cigarettes have a similar effect, with studies indicating that bleeding on probing is less common than in non-users of tobacco products.

We use bleeding as a diagnostic indicator for periodontal and peri-implant health. But bleeding on probing may be overrated as a diagnostic test and is less valid in a smoker than in a non-smoker.
If you find a patient has a smoking-associated oral disease—and periodontitis is the prime example of this—it may be the first adverse health effect from smoking that they have faced. This may provide an opportunity to engage with them and talk about smoking cessation.

Impact of smoking and vaping on treatment

In terms of periodontal therapy, treatment outcomes in smokers are inferior to those in non-smokers. Outcomes are also lower in smokers with regenerative therapy because the regenerative capacity of tissues is lower. We also know that smoking modifies peri-implant mucositis, but we need stronger evidence to say that it leads to more peri-implantitis.

However, smoking is clearly associated with implant failure through the lack of osseointegration. In a current heavy smoker, there is roughly double the risk of early implant failure. Smoking is also associated with peri-implant diseases very much like it is with periodontitis.

Some periodontists refuse to treat smokers with certain procedures. That is an extreme position because implants can still work in smokers, and smokers tend to lose more teeth and thus have a greater need for implants. But with smokers you would probably opt for therapies that are more conservative and less aggressive.

Benefits to oral health from stopping smoking

Within the first two months after stopping smoking, patients start to bleed again because the fluids are back to normal, there is more moisture in the mouth, and bad breath is slowly being eliminated. From an immunological perspective, it is believed that the host repairs the deficiencies in a matter of three or four or six months. But when it comes to the risk of periodontitis, it can take more than 10 years for the risk to fall to the same level as someone who has never smoked.

Large-cohort studies in both the USA and Germany have shown that the risk of tooth loss is indistinguishable from that of never-smokers 15 to 20 years after smoking cessation. That may not sound so optimistic, but it is an exponential decline. There are drops in risk early on and it then tapers more slowly.

How oral-health professionals can help in smoking cessation

Smoker status is now part of the classification of periodontal diseases—you have to ask patients about it and assess it. Maybe 20 years ago, many dentists did not know whether their patients smoked, but now smoking status is part of people’s dental history.

Oral-health professionals can play an important role because we may be the first ones to see a physical consequence of smoking in the form of periodontitis. Also, we may well see patients more regularly than their doctors.

We need to ask our patients about smoking and tell them about the risk associated with it and that their periodontal disease may be a consequence of their smoking. It they seem willing to consider quitting, we can steer them in the right direction in terms of cessation counselling. But dentists and periodontists should probably not be involved in cessation per se.