As more states across the US are legalizing marijuana, its consumption is becoming less taboo and more people are talking with their dentists about the risks of smoking in regards to gum and tooth health. This has caught the oral health experts largely off guard, as very few studies have been done in this area, unlike with other products such as tobacco. Of the studies currently published, most were poorly conducted or rely on epidemiological data rather than more robust clinical trials.

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However, according to a 2008 review paper on the subject, it was concluded that common side effects of marijuana smoking include xerostomia (chronic dry mouth), leukoedema (white, filmy mucous layers), increased incidence of periodontal disease, increased prevalence and density of the fungus Candida albicans, and oral cancers.

The short answer to is smoking marijuana bad for your teeth is, of course, yes. As it would be for smoking anything. Most physicians would suggest that if you are going to use marijuana then you should consume it orally or vaporize it to get the beneficial effects with less health risk. However, that’s not to say that vaping is risk free (in this case, we’re referring to vaping oil, not dry flower.) Some have actually found that vape oils containing glycol or glycerin may have cariogenic properties.

While most studies conducted are looking at vaping tobacco, a lot of cannabis oil vape cartridges include these two ingredients as cutting agents in order to make their concentrate more vape-able, so the risk is still present in the absence of nicotine. If you want to avoid vaping any harmful cutting agents, you will probably want to try switching to a full-spectrum extract instead.

However, this is also a matter of personal choice, so it is relevant to maybe rephrase the question to “how bad is smoking for your teeth?” To investigate this question further, we have summarized several scientific studies and reviews regarding marijuana use and oral health to get an idea of just how bad it can be for frequent users.

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Doctor dentist showing patient's teeth on X-ray iStock / alfexe

The Side Effects Of Marijuana Smoking On Oral Health

A comprehensive review from 2005 in the Australian Dental Journal concluded that marijuana abusers generally had poorer overall oral health than non-users. This included an increased risk of tooth decay, periodontal disease, and oral infections as well as higher plaque scores and less healthy gums. The study also cited a condition unique to marijuana smokers known as ‘cannabis stomatitis,’ in which the thin lining of cells around the mouth undergoes changes. This process can lead to small, chronic lesions in the tissues, and increase the risk for oral cancers. However, it should be noted that the same study concluded that “current knowledge on the effects of cannabis on periodontal health is inadequate.”

A more recent study from the Journal of Periodontology (2017) looked at data from 1,938 dental patients who were asked about marijuana use and corrected for tobacco, age, and alcohol use. The study looked at probing depth (an indicator of periodontal disease) and tooth decay and concluded that both were significantly higher among frequent users than non-users. A mechanism was not proposed in the study, and although multivariate analysis did rule out many lifestyle-related factors it is difficult to imply causation based on the methods of the study. 

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How Serious Is The Threat?

Both studies discussed above concluded that marijuana smoking could be tied to decreased oral health and tooth decay, and with what is known about tobacco smoking this seems intuitively plausible. However, not all studies agree. A small 2009 study in Chile looked at adolescents who admitted to smoking marijuana regularly and found no evidence of increased periodontal disease. Similar conclusions were made in a 2011 study on the effect of several different drugs on oral health, and found that only opiates were significantly associated with any decrease in oral health over a 1-year study period.

What About Oral Cancers?

Plaque of the patient, stone. Dentistry treatment of dental plaque, professional oral hygiene. The concept of harm to smoking and cleaning teeth iStock / undefined undefined

Another major concern regarding smoking any substance is oral and throat cancers. The causative effects of smoking tobacco and developing cancers are well documented, and the mechanisms have been well described. However, for marijuana causation is harder to prove at this time due to a lack of data and trials. Many studies have indicated that frequent marijuana smokers are more prone to several types of cancer, primarily of the mouth and neck.

The 2005 review from Australia quoted earlier also discussed oral cancers, stating that chronic marijuana smokers have an increased risk of both leukoplakia (white patches on the gums and tongue) and oral cancers. They sited carcinogenic compounds found in the smoke, including aromatic hydrocarbons, benzopyrene, and nitrosamines, all of which are about twice as abundant in marijuana smoke than cigarette smoke.

The study also implicated the different methods used to smoke marijuana than tobacco as more harmful, including not using filters, breathing in more deeply, and holding the smoke in. However, due to limitations in the studies that were reviewed, the authors could not make any strong conclusions, primarily because the effects of smoking marijuana and tobacco could not be separated in the study population.

Other reviews have found no clear association between marijuana and oral cancers.  However, most studies have some degree of confidence that marijuana smoking will lead to higher rates of oral and throat cancer, especially in young adults. However, although more evidence is needed, early findings suggest that smoking cannabis may have a lower risk of causing cancer than tobacco. That being said, some issues with current studies and data include:

    • A significant amount of cannabis consumers also consume tobacco.
    • The typical tobacco smoker consumes a greater quantity of tobacco than the quantity of marijuana smoked by the average cannabis consumer.

What Can I Do To Limit Health Concerns?

So, although the science regarding marijuana and the health of your teeth and mouth is far from conclusive, there is enough data to indicate that it is wise to be cautious. Based on current research, we have developed this short list of ways to keep yourself protected while still enjoying the benefits of marijuana use.

  • Consider other methods of consumption such as edibles, vaporizers (remember that this isn’t a completely risk-free option either), tinctures, or oils.
  • Avoid adding tobacco to joints, or consider stopping using tobacco altogether.
  • Be sure to maintain better than average oral hygiene.
  • Use Biotene®, or other dry mouth products to prevent chronic dry mouth which can lead to tooth decay.
  • Ask you doctor about oral probiotics, which have been shown to improve ‘good bacteria’ in the mouths of smokers.
  • See you dentist yearly, or more frequently is you suspect anything is wrong.
  • Talk to your doctors and dentists about your marijuana use (even if you live in an illegal state) so they are aware of the additional health risks or precautions necessary.