Your mouth on cannabis: Our oral health team joins the cannabis conversation

With the recent legalization of cannabis in Canada, we’ve been talking a lot about the potential health impacts. We’ve asked the public about cannabis attitudes, use and potential knowledge gaps and used the results to launch and a video campaign about the health effects of using cannabis and ways to reduce harm. We want you to be able to make an informed decision about cannabis use.

Now, our Oral Health team is joining the cannabis conversation. Have you ever wondered what the impact of cannabis is on our oral health? And what should you know about using cannabis before a dental appointment?

The impact of cannabis on oral health (or, your mouth)

Close-up of a mouth in the dental chair

The impact of smoking and chewing tobacco on your oral health is well known. We’ve all seen alarming pictures of a smoker’s mouth on a cigarette package—stained teeth, plaque build-up, gum disease, red or white spots that are potential signs of oral cancer. But what about cannabis? How does it impact our oral health?

It’s important to remember that cannabis affects people differently. The research on the health impacts of cannabis is still evolving and can vary depending on how long and how often cannabis is used, potency (strength) of the product, individual factors and the age it starts.

Here’s what we do know:

  • Studies show that cannabis use is associated with poor oral health outcomes.
  • Regular users are at a higher risk for tooth decay, plaque accumulation, and gingivitis when compared to non-users.
  • Smoking cannabis has been shown to increase the risk of periodontal disease (also known as gum disease), an infection of the tissue that holds teeth in place.

However, the association between cannabis use and poor oral health outcomes can be complicated by other factors including tobacco, alcohol and other drug use and oral hygiene practices.

Effects of cannabis on oral health

Senior couple brushing their teeth together

Dry mouth

Using cannabis in any form reduces saliva and can cause dry mouth. Dry mouth may lead to difficulty in chewing, swallowing and speaking, and increases the risk of oral health issues such as tooth decay and gum disease. Turning to sugary drinks to combat dry mouth will also increase the risk of tooth decay. If you choose to consume cannabis, drink lots of water to help deal with dry mouth. 


Cannabis stimulates cravings and appetite. Grabbing for the “munchies” after cannabis use increases the risk of tooth decay.


Smoking cannabis can lead to inflammation in the mouth and changes to the oral soft tissues. Cannabis users are at a higher risk of developing lesions and precancerous conditions. Cannabis smoke contains many of the same toxic chemicals as tobacco smoke. However, more research is needed to determine if smoking cannabis alone is a risk factor for oral cancer.


Cannabis users are more prone to oral infections. Some research shows that cannabis use may weaken a person’s immune response.   


Smoking cannabis can stain the teeth and cause bad breath.


Eating cannabis-infused edibles such as baked goods means added sugar intake and greater risk of tooth decay. If you choose to consume edibles, make sure to rinse your mouth with water afterwards.

The impact of cannabis use on a dental appointment

Man admiring his teeth from a dental chair

Let’s have the conversation! It’s important for everyone using cannabis to consider the impact on their oral health and implications for dental care.

The Canadian Dental Hygienists Associations’ resource Impaired in the Chair is great starting point for a conversation with your dental team. If cannabis use is part of your medical history, be open with your dental team about it, especially if you’ve consumed it before your dental appointment.

If you go to a dental appointment while intoxicated, you might have to reschedule. Your dental team is obligated to provide you with safe dental care and will use their professional judgement accordingly.

How can cannabis affect your dental appointment? Consider the following side effects:

Fast heart rate and anxiety

Cannabis use may increase the heart rate and can lead to negative reactions like anxiety or panic. These side effects may worsen or last longer with anesthetics used for dental treatment.

Interactions with medications

Cannabis may change the effectiveness of prescribed medications.

Increased bleeding

Cannabis may increase bleeding and affect healing.

Confusion and lack of focus

Cannabis use before a dental appointment could impair judgement and the capacity to provide consent to treatment.

Your dental team are oral health experts and you can feel comfortable speaking with them about this important and emerging topic. If you have used cannabis prior to your dental appointment, call a relative or friend to pick you up, DO NOT drive impaired.

More resources about cannabis

Free dental care for children and youth (17 and younger)

If you can’t afford dental care, we have free services for your children at Public Health. We provide free basic dental care, including cleanings, x-rays, check-ups and treatment to children and youth. 

Our dental hygienists provide preventive services (e.g. cleanings) out of all Public Health locations. If you cannot afford dental care for your child, please call our Dental Line to book an appointment. 

Our dentist provides dental care to children and youth enrolled in the Healthy Smiles Ontario program in Guelph at our 160 Chancellors Way office.

Have this card? Call Public Health to book an appointment.

Healthy Smiles Ontario card

For more information about our dental services, call our Dental Line at 1-800-265-7293 ext. 2661 or visit our Dental and Oral Health page.

Oral Health Team