Cannabinoids and Dental Caries: Oral Health Evidence
Dental caries is the medical name for tooth decay: the slow damage that ends in a cavity. A dentist treats it; medical cannabis does not. What research links cannabis and dental caries comes from two directions: observational studies, mostly of people who smoke it, find more untreated decay, while laboratory and early in-mouth studies test whether cannabinoids such as CBD, THC and CBG slow the bacteria behind cavities.
Built on peer-reviewed research published from 2017 to 2026: small studies in people, observational surveys, laboratory work and dental-materials research
The short answer, by how cannabis is used
- Smoke and vapor
- This is where the cavity research points. Smoke and hot vapor dry the mouth and pass over the gums and teeth, and the people in the studies who smoked cannabis also ate more sugar and often used tobacco [1].
- Any form with THC
- Dry mouth, snacking and a racing heart can come with THC however it is taken. THC also matters on the day of dental work, because of the epinephrine in the numbing medicine dentists use [1].
- Forms that are not inhaled
- Edibles, capsules, tinctures and creams avoid smoke on the teeth and gums. What remains: gummies, chocolates and drinks carry sugar of their own, and THC in any form still acts on the whole body. The choice of form is a conversation with a physician, not a fix.
When a tooth starts to hurt: what decay feels like
Tooth decay is quiet for a long time. By the time most people notice it, the damage has gone through the hard outer enamel into the softer layer underneath, and that is when a tooth starts to talk back.
A twinge with sweets, cold drinks or hot coffee
The first sign is often a short, sharp zing when something sweet, cold or hot touches one spot. It fades in seconds, so it is easy to chew on the other side and forget about it. That zing means the protective enamel over that spot is thinning or already broken, and fluid inside the tooth is reacting to the temperature.
An ache that wakes you at night
When decay reaches the pulp (the living center of the tooth, with its nerve and blood vessels), the pain changes. It throbs on its own, lingers after the cold drink is gone, gets worse lying down and can spread to the ear, jaw or temple, so it is hard to tell which tooth it is. Left alone, the pulp can die and an abscess, a pocket of pus at the root, can form. Then a tooth that could have had a filling may need a root canal or come out.
Fear of the chair, and of being judged
Many people put off the dentist because the last visit hurt, because of cost, or because they worry about what the dentist will think if they mention cannabis. That last worry is common and worth letting go of: dentists ask about cannabis for the same reason they ask about any medicine. It changes how they plan anesthesia and care, not what they think of you.
Waiting does not make a cavity smaller. Decay only reverses at the very first stage, a chalky white spot, and the cost and discomfort of treatment grow with every layer it reaches.
What is dental caries? Definition, meaning and ICD-10 code
Dental caries is a disease in which acid made by bacteria in dental plaque dissolves the minerals of a tooth, layer by layer, until a hole, a cavity, forms. In everyday terms, caries means tooth decay; the cavity is what it leaves behind. The word comes from the Latin for “rot,” and dentists use “caries” for both one decayed spot and the disease as a whole.
It is a disease of balance rather than a single event. Every time you eat sugar or starch, plaque bacteria produce acid and the enamel loses a little mineral; saliva, fluoride and time between snacks put mineral back. Caries develops when the losses keep winning.
Caries: the disease
What it is: the ongoing process of acid wearing away the tooth from the outside in.
What you see: at first nothing, then a chalky white or brown spot.
What is treated: the conditions in the mouth: plaque, sugar, saliva, fluoride.
Cavity: the hole it leaves
What it is: the physical defect where tooth structure has broken down.
What you see: a dark pit, a crack, food catching in one place, or nothing until an X-ray.
What is treated: the tooth: cleaning out decay and filling, crowning or removing it.
Find the code for a diagnosis
The code is on your dental chart or claim; pick what the dentist described. Codes follow the official ICD-10-CM, the US diagnosis code set [2].
Where is the decay?
How deep?
–
Choose where the decay is.
All codes as a table
| Code | Official title | What it means |
|---|---|---|
| K02 Dental caries | ||
| K02.3 | Arrested dental caries | Decay that has stopped progressing; often a hard, dark spot that needs watching, not drilling. |
| K02.51 | Dental caries on pit and fissure surface limited to enamel | Early decay in the grooves of a chewing surface, still in the outer layer. |
| K02.52 | Dental caries on pit and fissure surface penetrating into dentin | Groove decay that has reached the softer inner layer; usually filled. |
| K02.53 | Dental caries on pit and fissure surface penetrating into pulp | Groove decay that has reached the nerve; often a root canal. |
| K02.61 | Dental caries on smooth surface limited to enamel | Early decay on a flat side of a tooth, often between teeth. |
| K02.62 | Dental caries on smooth surface penetrating into dentin | Smooth-surface decay into the inner layer; usually filled. |
| K02.63 | Dental caries on smooth surface penetrating into pulp | Smooth-surface decay that has reached the nerve. |
| K02.7 | Dental root caries | Decay on a root exposed by receding gums, common in older adults. |
| K02.9 | Dental caries, unspecified | Decay recorded without its site or depth. |
| K05 Gum disease (for comparison) | ||
| K05.10 | Chronic gingivitis, plaque induced | Long-standing gum inflammation from plaque, without bone loss. |
| K05.30 | Chronic periodontitis, unspecified | Gum disease that has damaged the tissue and bone holding the tooth. See periodontitis and cannabis. |
| F12 Cannabis-related | ||
| F12.90 | Cannabis use, unspecified, uncomplicated | Cannabis use noted in the record, without a use disorder. |
| F12.10 | Cannabis abuse, uncomplicated | A problem pattern of use diagnosed by a clinician. |
Quick answers
Is dental caries infectious?
Partly. The bacteria involved, above all Streptococcus mutans, can pass from person to person, for example from a parent to a young child through shared spoons. But passing bacteria on is not the same as passing on decay: a cavity forms only when those bacteria are fed sugar often enough to keep the mouth acidic. That is why caries is called a non-communicable disease driven by bacteria and diet.
What does K02.9 mean?
K02.9 is “Dental caries, unspecified” [2]: decay was recorded, but not where on the tooth or how deep it goes. A more specific code, such as K02.52 for groove decay into the dentin, is used when the dentist documents the site and depth.
Why is there no ICD-10 code for “chronic” caries?
ICD-10-CM sorts dental caries by where it is and how deep it has gone, plus a separate code for arrested decay [2]. Whether it moves fast or slowly is written in the dentist’s notes, not in the code.
Is dental caries acute or chronic, and is it infectious?
Dental caries is usually a chronic disease: it develops over months or years, with long quiet stretches. Dentists still describe some cases as acute, when decay spreads fast through several teeth at once.
Fast (acute, rampant)
What it is: decay that appears on many teeth within a short time, often on surfaces that rarely decay, with soft, light-colored damage.
Who it affects in children: toddlers who sip milk, juice or sweet drinks from a bottle or cup through the day or at night, often called early childhood caries.
Who it affects in adults: people with a very dry mouth (from medicines, radiation to the head and neck, or heavy drug use) and people who snack on sugar constantly.
What the dentist does: treats several teeth quickly, looks for the cause of the dry mouth or the sugar habit, and adds high-strength fluoride.
Slow (chronic)
What it is: decay that advances over months or years, often darker and harder, sometimes stopping on its own.
Who it affects in children: school-age children, usually in the grooves of the back teeth soon after they come in.
Who it affects in adults: most adults with decay: between teeth, around old fillings and on roots exposed by receding gums.
What the dentist does: watches early spots, fills cavities that have reached the dentin, and works on prevention.
So what kind of infectious disease is it? Caries is caused by bacteria, but not by one germ that you catch and then have. It grows out of biofilm (the sticky plaque layer where many species live together) when sugar keeps the plaque acidic for long stretches. The bacteria can spread between people; the disease spreads only with the diet and habits that feed them.
Children and adults
In young children, decay moves fast because baby-tooth enamel is thin, and a cavity in a front tooth can appear within months. Bedtime bottles, frequent juice and sticky snacks are the usual drivers, and fluoride varnish and sealants at checkups are the usual protection.
Adults get new decay too. Old fillings leak at their edges, gums recede and expose the softer root, and many common medicines dry the mouth. Later in life root decay becomes more common, which is why adults need checkups as much as children do.
What causes dental caries? Bacteria, sugar and acid
Four things have to meet for a cavity to form: a tooth, bacteria, sugar and time. Take one away and decay stalls.
The bacteria. Dental caries microbiology centers on a handful of acid-making species. Streptococcus mutans starts the process on enamel: it turns sugar into acid and builds a sticky coat of sugars around itself that glues plaque to the tooth. Lactobacillus species take over in deeper, already-softened cavities. Together with many other microbes they live as a biofilm, a layered community that is much harder to wash away or kill than free-floating bacteria.
The acid. Enamel starts to lose minerals when the pH at the tooth surface drops below about 5.5 [3]. After each sugary snack the plaque stays below that line for a while; saliva slowly brings it back.
The sugar, and how often. Sipping a sweet drink over an afternoon does more harm than the same sugar eaten at once with a meal, because it keeps the mouth acidic for hours. Sticky and starchy snacks that cling to the teeth do the same.
Dry mouth. Saliva rinses away food, neutralizes acid and carries minerals back into enamel. When it runs short, from medicines, mouth breathing, smoking, dehydration or cannabis, decay speeds up.
What moves the odds of having a cavity?
How to read it: each row compares two groups of first-year university students in a 2017 survey [4]. The dot is the best estimate of how much more or less likely one group was to have at least one cavity; the bar around it is the range the true value probably sits in (95% confidence interval); the vertical line in the middle means “no difference.” Rows to the right of the line raised the odds, rows to the left lowered them. Background, not a cannabis study
estimate · likely range (95% CI) · no difference
- Raised the odds
- Skipped the dentist because of cost3.06× the odds (1.4-6.7) [4]
- Poor oral hygiene2.59× the odds (1.6-4.2) [4]
- Rated their own oral health as poor2.43× the odds (1.24-4.77) [4]
- Lowered the odds
- Went for preventive checkupsabout two-thirds of the odds (0.41-0.99) [4]
- Used an electric toothbrushabout a third of the odds (0.17-0.77) [4]
- Sealant still on the back teethabout a fifth of the odds (0.05-0.97) [4]
Show as a table
| Compared | Odds ratio | 95% CI |
|---|---|---|
| Skipped dental care for financial reasons vs. others | 3.06 | 1.4-6.7 [4] |
| Poor vs. good oral hygiene | 2.59 | 1.6-4.2 [4] |
| Poor vs. good self-rated oral health | 2.43 | 1.24-4.77 [4] |
| Preventive dental visits vs. others | 0.63 | 0.41-0.99 [4] |
| Electric vs. manual toothbrush | 0.36 | 0.17-0.77 [4] |
| Sealant remnants vs. none | 0.22 | 0.05-0.97 [4] |
Cannabis is not on this chart: this survey did not ask about it, and the cannabis studies below report no ranges that could be drawn on the same scale.
Symptoms, stages and diagnosis: from white spot to abscess
Decay moves inward, one layer at a time: through the enamel, into the dentin underneath, then into the pulp, and finally out through the root tip into the bone. What you feel, what an X-ray shows and what the dentist can still do all change with that depth. Early on, dental caries looks like a dull, chalky patch; later it turns brown or black, and a hole may catch food or floss.
How deep is it?
Pick a stage: your dentist names it from the exam and X-ray.
Stage 1: White spot
What you notice: usually nothing. A dull, chalky white patch near the gum line or in a groove, sometimes seen when braces come off.
What the X-ray shows: often nothing yet; the change is on the surface.
What the dentist does: fluoride varnish, a higher-fluoride toothpaste, a sealant on grooves, and a plan to cut down sugary snacks.
Reversible? Yes. Minerals can return to the enamel and the spot can harden again.
Stage 2: Decay in the enamel
What you notice: a light brown or dark spot; rarely pain.
What the X-ray shows: a small dark shadow in the outer layer, best seen on a bitewing between the teeth.
What the dentist does: may watch it and strengthen it with fluoride, or place a small filling once the surface breaks.
Reversible? No: a broken surface does not grow back, but the spot can be stopped from spreading.
Stage 3: Decay in the dentin
What you notice: twinges with sweets, cold or hot; a visible hole; food catching in one place.
What the X-ray shows: a dark area spreading under the enamel toward the nerve.
What the dentist does: removes the decay and places a filling; a large cavity may need an inlay or crown.
Reversible? No. Dentin decay spreads faster than enamel decay and needs treatment.
Stage 4: Decay in the pulp
What you notice: throbbing pain that comes on by itself, lingers, wakes you at night or spreads to the jaw and ear.
What the X-ray shows: the dark area reaching the pulp chamber.
What the dentist does: a root canal to remove the inflamed pulp and save the tooth, or an extraction.
Reversible? No. Once the nerve is inflamed past a certain point it does not recover.
Stage 5: Abscess
What you notice: swelling of the gum or face, a pimple on the gum, a bad taste, pain on biting, swollen lymph nodes under the jaw, sometimes fever. Pain can stop when the nerve dies. The infection does not.
What the X-ray shows: a dark halo at the root tip, called a periapical lucency, where bone has been dissolved.
What the dentist does: drains the infection, then a root canal or extraction; antibiotics if the infection is spreading.
Reversible? No. An abscess needs care quickly.
How dentists find it: exam and X-rays
The dentist looks, dries the tooth with air and feels it gently. Decay between teeth and under old fillings is often invisible, so X-rays do the rest. Each kind answers a different question.
| Image | What it shows | When it is used |
|---|---|---|
| Bitewing | The crowns of upper and lower back teeth together; dark shadows between teeth and under fillings. | Routine checkups; the main tool for finding hidden decay early. |
| Periapical | One or two whole teeth, root tip included; periapical lucencies: dark areas of bone loss from infection. | A painful tooth, a suspected abscess, before a root canal. |
| Panoramic (OPG, Panorex) | All teeth and both jaws in one image; large cavities, impacted teeth, bone changes. | First visits, wisdom teeth, planning many treatments; less sharp for small cavities. |
| Cone-beam CT | A 3D view of teeth, roots and bone; the spread of an infection in the jaw. | Complex root canals, implants, unclear infections; not for routine cavity checks. |
See a dentist the same day, or go to urgent care, if you have swelling in the face, under the jaw or around the eye, a fever with tooth pain, trouble swallowing or opening your mouth, or swelling that spreads toward the neck. A tooth infection can spread to the jaw, the sinuses and, rarely, the bloodstream.
Is medical cannabis worth discussing with your teeth in mind?
Fourteen short questions about your teeth, your symptoms, how you use cannabis and your other diagnoses. Your answers stay on this page and show what to bring to your dentist and to a physician.
14 questions · about a minute · your answers stay in this browser
Can dental caries be reversed? Treatment, antibiotics and prevention
Only at the very beginning. While decay is a white spot in intact enamel, minerals from saliva and fluoride can move back in and the surface can harden. Once the surface has broken and bacteria are inside the tooth, the lost structure does not grow back. The best treatment is the one that removes the decay and seals the tooth.
Can be reversed
Stage: white spot lesions with an unbroken surface.
What works: fluoride toothpaste and varnish, fewer sugar hits a day, sealants on deep grooves, and good brushing along the gum line.
What to expect: the spot may stay visible but harden and stop growing.
Cannot be reversed
Stage: any cavity: a break in the enamel or decay in the dentin, pulp or root.
What works: removing the decay and restoring the tooth; nothing at home closes a hole.
What to expect: the earlier it is treated, the smaller and cheaper the repair.
Treatment by stage
Dental caries management follows the depth of the lesion. Choose a stage to see only its options.
| Stage | What is done | Goal |
|---|---|---|
| White spot (early) | Fluoride varnish, prescription-strength fluoride toothpaste, diet changes | Put minerals back and stop the spot |
| Early groove decay (early) | Sealant or a very small resin filling | Seal the groove so plaque cannot settle |
| Cavity in enamel or dentin (moderate) | Filling: tooth-colored composite, amalgam or glass ionomer | Remove decay, rebuild the tooth |
| Large cavity (moderate) | Inlay, onlay or crown | Protect a weakened tooth from cracking |
| Decay in the pulp (advanced) | Root canal treatment, then usually a crown | Remove the infected nerve and keep the tooth |
| Abscess or tooth beyond repair (advanced) | Drainage, root canal or extraction; antibiotics only if the infection spreads | Clear the infection, then replace the tooth if needed |
Prevention that works
- Brush twice a day with fluoride toothpaste, and spit rather than rinse so the fluoride stays.
- Clean between your teeth once a day with floss or small brushes.
- Keep sugar to mealtimes; sip water, not sweet drinks, between meals.
- Ask about sealants for deep grooves, for children and adults alike.
- Treat a dry mouth: water, sugar-free gum, and a talk with your doctor about medicines that cause it.
- See a dentist for checkups at the interval they recommend; preventive visits went with lower odds of a cavity in the survey above [4].
Caries and heart disease: a link, not a cause. People with poor oral health have more heart disease, and bacteria from an infected tooth can enter the blood. Untreated dental infection is also a recognized route to infective endocarditis in people with damaged heart valves. But no study shows that filling a cavity prevents a heart attack; smoking, diet and access to care drive both. If you have a heart valve problem, tell your dentist before any treatment.
Does cannabis use raise the risk of cavities?
People who use cannabis often have more untreated decay, but that comes from observational surveys, which show a link and cannot show that cannabis caused it. Almost all of these studies looked at smoking. Edibles, tinctures and other forms have not been studied for cavities at all.
“Crude” means the figure was not adjusted for other differences between the groups, such as income, smoking tobacco or how often people saw a dentist. Those differences matter, as the next chart shows.
Do people who smoke cannabis eat more sugar?
How to read it: each bar is the average amount of sugar eaten per day, in grams, by adults 21 and older in a national US survey; the longer the bar, the more sugar. Cross-sectional study of 4,173 adults, 2024 [1].
Why might people who use cannabis have more cavities?
Several explanations fit the data. Pick one, or read them all.
Dry mouth: cannabis can reduce saliva (xerostomia), and saliva is the mouth’s main defense against acid. Researchers note that lifestyle and income heavily muddy this link in real patients, and none of the surveys here measured saliva directly.
Sugar and snacks: in the national survey, people who smoked cannabis ate more sugar per day than people who did not [1]. The well-known “munchies” are one likely reason; sweet edibles and drinks add more.
Tobacco too: many people who smoke cannabis also smoke tobacco, and the same study points to a possible combined effect of the two on decay [1]. Separating them is hard in a survey.
Fewer dental visits: skipping the dentist because of cost was the strongest risk factor in the student survey above [4]. The cannabis surveys did not record dental insurance or checkups, so this cannot be ruled out. It was not measured in these studies.
Smoke itself: smoke and hot vapor dry and irritate the mouth. Whether cannabis smoke harms enamel directly has not been measured in these studies.
A 2020 meta-analysis pooled studies of people who use drugs (cannabis among many other substances) and found more caries and gum disease than in people who do not [6]. It does not isolate cannabis. A 2024 letter criticizing one of the cannabis surveys pointed out what is still missing: how many years people smoked, how much, at what age they started and whether they stopped [7].
What happens when cannabinoids meet cavity bacteria in the lab
Cannabinoids vs. cavity bacteria: lab and in-situ studies
The other half of the research asks the opposite question: could cannabinoids help keep cavity bacteria in check? Here “cannabinoid” means a single purified compound in a dish, a rinse or a lozenge, not smoking or eating cannabis. CBD and CBG do not cause a high; THC does.
Choose a substance to see what was tested.
| Substance | What was studied | Design | What came out |
|---|---|---|---|
| CBD (cannabidiol) | |||
| CBD mouthwash | Rinse vs. chlorhexidine 0.12% on enamel worn in the mouth, 14 volunteers [8] | Crossover randomized in-situ study | Favorable effect on enamel and biofilm reported; small sample |
| CBD lozenges | Lozenges with 300 mg of CBD a day for 15 days, 22 participants who finished [9] | Clinical trial | Fewer S. mutans in saliva than in the control group (p = 0.0299); very low certainty |
| CBD with triclosan | Growth and biofilm of S. mutans [10] | Lab study Lab only | Lowest dose that stopped growth: 5 µg/mL for CBD alone, 10 µg/mL for triclosan alone, 2.5 µg/mL combined |
| CBD alone | Effect on S. mutans and its biofilm [11] | Lab study Lab only | Antibacterial effect on the cavity bacterium reported |
| THC (tetrahydrocannabinol) | |||
| THC | Growth, biofilm and acid production of S. mutans [3] | Lab study Lab only | Stopped growth from 2 µg/mL and blocked about 90% of biofilm formation at 2 µg/mL and above; disturbed the bacterial membrane within 5 minutes |
| CBG (cannabigerol) | |||
| CBG | Antibacterial action against S. mutans [12] | Lab study Lab only | Antibacterial effect reported |
| CBG on biofilm structure | Microscope images of S. mutans biofilm [13] | Lab study Lab only | Live-cell signal in the middle layer fell by 28.9% at 2.5 µg/mL and 32.5% at 5 µg/mL; the biofilm became more porous (up 170.4% and 171.4%) |
| Dental materials | |||
| Glass ionomer cement with cannabinoids | Filling cement with 1 wt% cannabinoid fractions added [14] | Lab study Lab only | Less bacterial survival (S. mutans viability down to 47.35%, L. acidophilus to 14.77% in the best groups), but higher damage to cells: LDH release up to 113.41% of control |
Lab concentrations do not carry over to using cannabis: a compound in a dish touches bacteria directly, which smoking, vaping or eating cannabis does not do. Doses mentioned here are the ones used in studies, not advice. In one lab study the authors advise against CBD above 25 µg/mL, where it began to damage epithelial (lining) cells [10].
How strong is the evidence?
Not strong yet. A study in people tells you far more than a test tube, and for cannabinoids and dental caries the studies in people are few and small. Here is what exists at each level, from strongest to weakest.
| Level | What exists for dental caries | What it can and cannot tell you |
|---|---|---|
| Trials in people | A crossover in-situ study of a CBD mouthwash with 14 volunteers [8] and a CBD lozenge trial with 22 participants [9]. | Shows that CBD can lower cavity bacteria in a real mouth for a short time; too small and short to show fewer cavities. |
| Observational studies | National US surveys linking cannabis smoking with more untreated decay and more sugar [5][1]; a meta-analysis of people who use drugs [6]. | Shows links, not cause; tobacco, diet and dental access are tangled in. |
| Lab and dental materials | CBD, THC and CBG against S. mutans in dishes [3][10][13]; filling cement with cannabinoids [14]. | Explains why scientists are interested; says nothing yet about patients. |
How big is the effect?
Honestly, nobody can say. A chart of effect sizes needs several studies reporting the same outcome with a margin of error, and none of the cannabis studies here gives one: the survey figures are crude odds without ranges, and the trials measured bacteria, not cavities. That is why the only effect chart on this page is about ordinary risk factors.
Browse the studies yourself
Every study cited on this page, in plain words. Neutral and negative results are included.
A CBD mouthwash on enamel worn in the mouth
Volunteers rinsed with a CBD mouthwash, chlorhexidine and comparison rinses in turn; 13 completed every phase, and the CBD rinse showed a favorable effect on enamel and biofilm [8].
CBD lozenges and cavity bacteria
Lozenges with 300 mg of CBD a day for 15 days lowered S. mutans counts compared with control (p = 0.0299); 8 of 30 people were excluded, which weakens the result [9].
Frequent cannabis use and untreated decay
Current frequent users had 1.76 times the crude odds of untreated coronal caries compared with never users [5].
Cannabis smoking, sugar and decay
People who smoked cannabis ate more sugar (131.1 vs. 106.9 g a day); the authors raise tobacco and epinephrine as points for dentists [1].
Decay and gum disease in people who use drugs
People who use drugs had worse caries and gum disease; cannabis is one of many substances and is not analyzed alone [6].
How should cannabis exposure be measured?
A critique of one survey: without joint-years, starting age, duration and quitting, the link with decay is hard to read [7].
THC against Streptococcus mutans
THC stopped growth at 2 µg/mL and cut biofilm formation by about 90%, acting on the bacterial membrane [3].
CBD plus triclosan
Combining CBD with triclosan, an ingredient of some toothpastes, worked at lower doses than either alone [10].
CBD against the main cavity bacterium
CBD showed an antibacterial effect on S. mutans and its biofilm in the lab [11].
CBG and the structure of plaque
CBG thinned out live bacteria in the middle of the biofilm and made it more porous [13].
CBG against Streptococcus mutans
Cannabigerol, a non-intoxicating cannabinoid, showed antibacterial properties toward the cavity bacterium [12].
A phone thermal camera for early decay, and THC in saliva
A low-cost infrared method was tested both for spotting early caries and for telling saliva with 2 ng/ml of THC from saliva with none, with 95% accuracy [15].
Filling cement with cannabinoids
Adding cannabinoids to glass ionomer cement cut bacterial survival, but also raised cell damage: mixed results [14].
Ranking caries risk factors in university students
Skipping the dentist for cost and poor hygiene raised the odds of a cavity; checkups, electric toothbrushes and sealants lowered them [4].
Diet change and teeth among the Hadza of Tanzania
As foragers ate more maize and honey, their teeth showed the decay-promoting effect of those foods [16].
No studies of this type are cited on this page.
What kinds of studies is this evidence built on?
How to read it: each row is one kind of study, and the bar shows how many published studies on cannabinoids and dental caries are of that kind. Stronger designs are at the top. Gray bars are commentary and lab work, which cannot answer whether something helps patients.
Show as a table
| Design | Studies |
|---|---|
| Meta-analyses | 1 |
| Crossover randomized trials | 1 |
| Other clinical trials | 1 |
| Cohort studies | 2 |
| Cross-sectional studies | 5 |
| Case reports | 1 |
| Narrative reviews and letters | 5 |
| Lab studies | 9 |
| Who was studied | Studies |
|---|---|
| People in clinical studies | 3 |
| People observed, not treated | 6 |
| Whole populations | 9 |
| Cells and molecules | 7 |
| Research methods | 1 |
| Not classified | 17 |
Ways to use cannabis: what each form means for your teeth
Cannabis is not only smoked. People also vape it, eat it as gummies or chocolate, drink it, swallow capsules, hold drops under the tongue or rub creams on the skin. For your teeth the form matters: some forms pass over the gums and enamel, some bring sugar, and some barely touch the mouth. This section explains the differences; it does not recommend a form.
How do you use it, or how would you?
Choose the closest; most people combine more than one.
Specific to smoking
Joints, blunts, pipes and bongs burn plant material. The smoke dries the mouth and passes directly over the gums and teeth, and almost every cavity survey on this page studied people who smoke [5][1]. A blunt wrapped in tobacco leaf adds tobacco, which may add to the risk [1].
Specific to vaping and dabbing
Dry-herb vaporizers, oil pens and cartridges avoid burning, but hot vapor still crosses the same mouth and can dry it. Concentrates used for dabbing (wax, shatter, rosin) are very strong. No study here looked at vaping and cavities separately.
Shared devices
A pipe, vape or joint passed between people passes saliva along with it, and with it colds, cold sores and the bacteria that live in plaque.
Specific to edibles and drinks
Gummies, chocolates, baked goods, sodas and capsules avoid smoke entirely. Many of them are sweets, and sugar is a cause of decay in its own right, whatever is in it; a gummy that sticks to the teeth acts like any other candy. Edibles also act slowly and last for hours, so a second piece “because the first did nothing” is a common mistake. No study here measured cavities in people who use edibles.
Specific to tinctures and sprays
Drops held under the tongue and mouth sprays sit on the lining of the mouth for a while before part is swallowed. Some are made with alcohol or sweeteners. There are no data on what they do to teeth or gums with regular use.
Specific to topicals
Creams and balms act mainly where they are applied and do not touch the mouth. Transdermal patches are different: they deliver cannabinoids into the blood, so THC’s effects, dry mouth among them, count the same as any other form.
Specific to prescription cannabinoids
Dronabinol (Marinol, Syndros), nabilone (Cesamet) and cannabidiol (Epidiolex) are FDA-approved medicines prescribed by a doctor and filled at a pharmacy, not products bought with a medical card. None is approved for dental problems.
True of every form
- THC can dry the mouth and bring on snacking, both of which feed decay.
- THC can speed up the heart, which matters with the epinephrine in dental anesthetic [1].
- Anything that reaches the blood is handled by the liver and can change levels of other medicines.
- Lab results on CBD or THC against bacteria do not apply to using cannabis in any form.
Choosing a form is a conversation for the appointment.
All forms as a table
| Form | What it avoids | What remains |
|---|---|---|
| Smoking | – | Smoke over teeth and gums, dry mouth, often tobacco, shared devices, all effects of THC |
| Vaping & dabbing | Burning plant material | Hot vapor in the mouth, dry mouth, strong concentrates, shared devices, all effects of THC |
| Edibles & drinks | Smoke and vapor, shared devices | Sugar in many products, slow and long effect, risk of a repeat dose, liver processing |
| Tinctures & sprays | Smoke and vapor, shared devices | Contact with the lining of the mouth, alcohol or sweeteners in some, all effects of THC |
| Topicals | Contact with the mouth, most whole-body effects | Skin reactions |
| Transdermal patches | Smoke, vapor and swallowing | Whole-body effects of THC, interactions |
| Prescription cannabinoids | Unknown product content | Side effects of the medicine; not approved for dental problems |
Cannabis and gum (periodontal) disease
Caries and gum disease are different diseases of the same mouth. Caries attacks the tooth itself; periodontal disease attacks the gums, ligament and bone that hold the tooth in place, and it is the more common reason adults lose teeth later in life. They share roots, though: both start with plaque biofilm, both get worse with a dry mouth, and smoking feeds both.
A meta-analysis of people who use drugs found more of both caries and gum disease than in people who do not [6], and that study does not separate cannabis from the other substances. The full picture for gums, what studies show and what they do not, has its own page.
Periodontitis and medical cannabisWhat the research says about cannabis and gum disease.What science doesn’t know yet
The gaps here are not a footnote; they are most of the story. The researchers themselves list the same problems again and again.
- One bacterium in a dish is not a mouth. The THC study used a single strain of S. mutans, without the mix of species, the saliva flow or the way the body handles THC in people who use cannabis [3].
- Safety for the mouth’s own tissues is untested. CBD began to harm lining cells above 25 µg/mL in the lab [10], the cannabinoid filling cement raised markers of cell damage, and its authors call for tests on cells from the mouth before any clinical use [14].
- Structure, not just counts. Some biofilm studies measured how many bacteria survived but not how the plaque was built, and had no planned sample size [8].
- Tiny human studies. The CBD lozenge trial lost 8 of 30 participants and relied on surveys and saliva samples that vary [9].
- Cause or coincidence. The surveys are snapshots: they cannot tell whether cannabis came before the decay, and self-reported drug use is open to recall bias and to people playing it down [5][1].
- How much, how long, which form. No study recorded years of use, amount, age at starting, or whether people ate or vaped instead of smoking [7][5][1].
- Medical versus recreational use. The surveys do not say why people used cannabis, and gum data were missing from one survey cycle [5][1].
Before your dental visit: tell your dentist about cannabis
Your dentist is not asking to judge you. Cannabis changes how your body handles anesthetic, sedation and healing, and the dentist can only plan around what they know. A sentence on the intake form – what you use, how often and when you last used it – is enough to start, and it stays in your health record like any other medicine.
Open each point below. This is what the studies recorded, not a complete list.
Epinephrine in local anesthetic clinical data
Most dental numbing injections contain epinephrine, which makes the heart beat faster. Recent cannabis use can do the same, and researchers flag a possible abnormal stress response with a racing heart when the two meet [1]. Tell the dentist if you used cannabis on the day of treatment; they can adjust the anesthetic or reschedule.
Sedation and general anesthesia
If you are having a tooth removed under sedation or general anesthesia, regular cannabis use can change how much medicine you need and how you wake up. The studies on this page did not measure it; the anesthesia team will ask you directly, and an honest answer keeps the dose right.
Tobacco at the same time clinical data
Smoking tobacco alongside cannabis may add to the risk of decay [1] and slows healing after extractions and gum treatment. Mention both, and ask how long to avoid smoking after the procedure.
What to tell your dentist
Tap each item as you get it ready.
Who should not use cannabis around dental care
For some people the answer is “not now” or “not without a physician’s plan,” whatever the reason for using it.
- Pregnancy or breastfeeding – THC reaches the baby, and studies of cannabinoids in the mouth did not include pregnant women.
- Sedation or general anesthesia coming up without telling the dental or anesthesia team, who need to plan the dose.
- Heart rhythm problems – THC and the epinephrine in dental anesthetic can both speed the heart [1].
- An active tooth infection with swelling or fever – that needs a dentist first; cannabis can dull the pain while the infection spreads.
- A history of psychosis – THC can bring it back or make it worse. See cannabis and psychosis.
- A known allergy to hemp extract or to ingredients of a CBD product such as lozenges [9].
Does dental caries qualify for a medical marijuana card?
Usually not by itself. State medical cannabis programs list conditions such as chronic pain, cancer or seizure disorders, and tooth decay is not typically named on them. What counts is a diagnosis in your records that matches your state’s list, and a physician licensed in your state confirms that match at the evaluation.
Lists change as legislatures and health departments update them, so the current wording for your state is the one that counts.
A listed condition applies
You have another diagnosis that is on your state’s list. That diagnosis, not the cavity, is what the physician evaluates. Bring the record.
Dental pain became chronic pain
Jaw or facial pain that has lasted for months, diagnosed by a dentist or doctor, may fall under chronic pain where your state lists it. A cavity waiting for a filling does not.
Nothing on the list
Some states let physicians certify other conditions they judge debilitating, and adult-use states sell without a card.
What else has a doctor diagnosed?
State lists name diagnoses, not symptoms: pick what is in your records.
Pick what is in your records.
Chronic pain: the most widely listed condition across state programs, and long-lasting jaw or facial pain can belong here. Read chronic pain and medical cannabis.
Headache: pain from a tooth or the jaw joint can feel like a headache, and some programs list chronic headache or migraine. Read headache and medical cannabis.
Anxiety: several states list anxiety disorders or accept them under broader wording; fear of the dentist on its own is not a diagnosis. Read anxiety and medical cannabis.
Gum disease: periodontitis is rarely on a state list by name, but it has its own research. Read periodontitis and medical cannabis.
None of these: then the decision rests on your state’s wording and the physician’s judgment. Start with your state’s medical marijuana laws.
Medical card or recreational purchase
In states with adult-use sales, adults can buy without a card. A card still changes several things, though the details are set state by state.
| Aspect | With a medical card | Recreational |
|---|---|---|
| Taxes | Often lower; some states waive part of the cannabis tax for patients | Full state and local cannabis taxes |
| Purchase and possession limits | Often higher; depends on your state | Set for adult-use buyers |
| Products | Medical dispensaries and, in some states, medical-only products | Adult-use product range |
| Age | Patient age rules set by each program | Adult-use age limit set by the state |
| Physician involvement | A licensed physician reviews your conditions and medicines | None |
| Document | State card or recommendation, recorded in a confidential registry | Government ID only |
Will a card save you money?
It can, but only where your state taxes patients less than recreational buyers, and the amount depends on your state’s tax rates and how much you buy. Weigh that against the evaluation fee and any state registration fee. The breakdown is in medical vs. recreational cannabis taxes, and the wider differences in medical and recreational cannabis compared.
What the program in your state involves
Qualifying is the first of two steps. In most states a physician’s recommendation is followed by registration with the state health department, which issues the card and enters you in a confidential patient registry. Purchases happen at licensed dispensaries, where products are lab-tested and labeled with their THC and CBD content. Possession limits, home growing, taxes and the role of registered caregivers under each state’s law are listed state by state on the laws and regulations pages.
Moving to a new state? A card from one state is not automatically valid in another. See which states accept out-of-state cards – and you would apply in your new state’s program.
What this means if you are considering it
Medical cannabis will not fix a cavity, and nobody on the medical side will tell you it does. Where it may fit is the bigger picture a physician looks at: a qualifying condition, the medicines you already take, and how cannabis, in whatever form, sits with your teeth and your dental care.
Questions worth asking
- Which form fits my condition, and what does it mean for my mouth?
- THC, CBD or both, and how will it affect a dry mouth?
- Do any of my current medicines interact?
- Is there anything I should avoid before dental work?
- What should make me stop and call you?
An evaluation makes sense if
- You have a diagnosis that your state may list, such as chronic pain.
- Your teeth are being looked after by a dentist.
- You can share your full medicine list.
- You want a physician’s view rather than guesswork.
It is not the right step if
- The hope is to fix or prevent a cavity with cannabis.
- You have tooth pain with swelling and have not seen a dentist.
- Dental sedation is days away and not yet discussed.
- You are pregnant or breastfeeding.
This page summarizes published research for education. It does not replace advice from your dentist or physician. Cannabis does not treat or prevent tooth decay, and the studies of cannabinoids against cavity bacteria are mostly laboratory work.
How to get a medical card online
Everything happens online, so there is nowhere to travel. Four steps take you from the first form to a card in your hand.
Fill in the intake form
Your state, your diagnoses and your current medicines. Have records of any qualifying diagnosis ready to upload.
See a physician licensed in your state
A one-on-one appointment online. You agree on the time with the physician; keep an hour free rather than a minute.
Receive your signed recommendation
If the physician approves, the signed recommendation arrives in your account.
Register with your state
Where required, you submit the recommendation to the state program, which reviews it and issues the card.
Which path fits you
First card
Start with the four steps above. Choose your state from the list at the top of this page, and have your diagnosis records ready.
Renewal
Your card is close to expiring. You repeat the evaluation with updated medicines. See renewing your card below.
Moving to a new state
Cards rarely transfer. You apply in your new state’s program; check which states accept out-of-state cards for the time in between.
What you end up with
Across 250 reviews from patients in the states where we are licensed. We do not sort them by score and do not hide the low ones.
- 150,000+patients evaluated – everyone who has been through an appointment with us, in every state where we are licensed
- Since 2017doing only this: online evaluations for medical cannabis programs, and nothing else on the side
A recommendation from a physician licensed where you live, and, once your state registers it, a card that lets you buy at licensed dispensaries. Your documents stay in your account and documents, and how the medical card works explains the evaluation in detail. The physicians who see patients and review this page are listed on our physicians page.
Programs for veterans and for people with low income are available in some states. The evaluation fee for your state is shown before you pay; a state registration fee, where one exists, goes to the state separately.
Renewing your medical card
Cards expire on a schedule your state sets. Renewal is a repeat evaluation with your updated medicines and diagnoses, followed by the state’s renewal step; your current documents are in your account. Renewal pages by state:
Choose your state’s renewal page
Legal protections: privacy, firearms and work
Privacy: your medical records are protected under the HIPAA Privacy Rule [17], and state patient registries are confidential; dispensaries and law enforcement can usually check only whether a card is valid.
Firearms: federal law bars anyone who is an “unlawful user” of a controlled substance from having a firearm [18], and cannabis remains federally controlled, so a state card does not change the federal rule.
Work: employment protections for card holders differ by state, and many employers can still enforce drug-free policies. Read your state’s rules on the laws and regulations pages.
Questions people ask about dental caries and cannabis
Does smoking cannabis cause cavities?
It is linked to them, but cause is not proven. In a national US survey, frequent cannabis users had 1.76 times the crude odds of untreated decay compared with never users [5], and people who smoked cannabis also ate more sugar [1]. Dry mouth, sugar, tobacco and fewer dental visits all play a part, and the surveys cannot separate them.
Dental caries is what type of infectious disease?
A bacterial, biofilm-driven disease that is not contagious in the usual sense. The bacteria – mainly Streptococcus mutans – can pass between people, but decay develops only when frequent sugar keeps the plaque acidic.
Is dental caries acute or chronic?
Mostly chronic: it develops over months or years. Fast, widespread decay is called acute or rampant caries and is seen with very dry mouths and in young children with frequent sugary drinks. See fast and slow decay compared.
Can dental caries be reversed?
Only at the white-spot stage, before the surface breaks. Fluoride, less frequent sugar and good cleaning can harden it again. A cavity does not close on its own, and no home remedy fills it.
Do antibiotics treat dental caries?
No. Antibiotics cannot reach decay inside a tooth. They are used when an infection spreads beyond it: facial swelling, fever, swollen lymph nodes, and always together with treating the tooth.
What is the ICD-10 code for dental caries, and for cannabis use?
Dental caries is coded K02: K02.9 when unspecified, K02.51 – K02.53 for pit and fissure decay, K02.61 – K02.63 for smooth surfaces, K02.7 for root caries and K02.3 for arrested caries. Cannabis use without a disorder is F12.90; cannabis abuse is F12.10 [2]. The code finder above walks through them.
Can a CBD mouthwash prevent cavities?
Can I use cannabis before dental work?
Tell your dentist first. THC can speed the heart, and so can the epinephrine in local anesthetic [1]; with sedation, regular use can change the dose you need. Your dentist may adjust the plan or ask you to wait. See what to tell your dentist.
Does cannabis cause dry mouth, and does that matter for teeth?
Yes, THC commonly dries the mouth, and saliva is what neutralizes acid and repairs early enamel damage. Sip water, chew sugar-free gum, avoid sweet drinks while your mouth is dry, and tell your dentist: they may suggest a higher-fluoride toothpaste.
Are cannabis gummies bad for my teeth?
The sugar in them is, like any candy – it has nothing to do with the cannabis. Sticky gummies cling to the grooves of back teeth. If you use them, having them with a meal and brushing or rinsing afterward limits the acid attack. No study has measured cavities in people who use edibles.
What about delta-8 THC or hemp CBD products sold without a card?
Hemp-derived products sold in shops and online are often less tightly regulated than dispensary products, and labels may not match what is inside. Delta-8 THC acts much like regular THC, dry mouth included. A product sold as a CBD toothpaste or rinse has not been tested the way the study formulas were.
Can a decayed tooth cause swollen lymph nodes, sinus problems or sepsis?
Yes, once decay becomes an abscess. Lymph nodes under the jaw can swell, an infected upper back tooth can inflame the sinus above it, and, rarely, infection spreads to the blood or the heart valves. Swelling, fever or feeling unwell with tooth pain needs a dentist or urgent care the same day.
Can I use my card in another state, or replace a lost one?
Some states honor cards from other states and many do not. Check which states accept out-of-state cards and traveling with cannabis before a trip. A lost card can usually be replaced by the program that issued it. See what to do if your card is lost.
How do I renew my medical card?
Renewal is a repeat evaluation with your updated medicines, then the state’s renewal step. Your current documents are in your account, and each state has its own renewal page.
Is an online evaluation legitimate?
Yes, where state law allows telemedicine for medical cannabis evaluations. The appointment is with a physician licensed in your state, one-on-one, and the recommendation is the same document an in-person visit would produce. How the medical card works explains each step.
Who finds out? Privacy, firearms and work
Privacy: your medical records are protected under the HIPAA Privacy Rule [17], and state registries are confidential. Firearms: federal law bars “unlawful users” of controlled substances from having a firearm [18], and a state card does not change that. Work: protections differ by state; see the laws and regulations pages.
More research on cannabis and dental caries
This page cites a selection of studies. Our research library holds every study we track on cannabis and dental caries, from laboratory work to clinical trials, and lets you filter them by cannabinoid, study type and year.
- studies
- 49
- in people
- 18
- clinical trials
- 2
References
18 sources
- 1. The Effect of Marijuana-Smoking on Dental Caries Experience. DOI: 10.1016/j.identj.2024.01.009 PMID: 38355392
- 2. Centers for Medicare & Medicaid Services. ICD-10-CM: International Classification of Diseases, Tenth Revision, Clinical Modification. 2026.
- 3. In Vitro Antimicrobial Effect of Tetrahydrocannabinol on Streptococcus mutans and Its Anticariogenic Potential. DOI: 10.1016/j.identj.2025.109386 PMID: 41576726
- 4. Hierarchizing caries risk factors among first-year university students in Nice (France): a cross-sectional study. DOI: 10.1186/s12903-017-0452-8 PMID: 29268726
- 5. Oral health status among recreational cannabis (marijuana and hashish) users in the USA: A NHANES-based cross-sectional study. DOI: 10.1016/j.sdentj.2024.01.015 PMID: 38690380
- 6. Dental caries and periodontal disease among people who use drugs: a systematic review and meta-analysis. DOI: 10.1186/s12903-020-1010-3 PMID: 32041585
- 7. Marijuana Smoking and Dental Caries: A Letter. DOI: 10.1016/j.identj.2024.08.015 PMID: 39317589
- 8. Effect of a cannabidiol-based mouthwash on dental enamel properties and biofilm control: an In situ study. DOI: 10.1007/s00784-026-06985-7 PMID: 42380527
- 9. Antimicrobial Effects of Cannabidiol (CBD)-infused Lozenges against Streptococcus mutans in Oral Health. DOI: 10.1590/0103-644020245988 PMID: 40136134
- 10. Improved Anti-Biofilm Effect against the Oral Cariogenic Streptococcus mutans by Combined Triclosan/CBD Treatment. DOI: 10.3390/biomedicines11020521 PMID: 36831057
- 11. Anti-Bacterial Effect of Cannabidiol against the Cariogenic Streptococcus mutans Bacterium: An In Vitro Study. DOI: 10.3390/ijms232415878 PMID: 36555519
- 12. Anti-Bacterial Properties of Cannabigerol Toward Streptococcus mutans. DOI: 10.3389/fmicb.2021.656471 PMID: 33967995
- 13. Cannabigerol Effect on Streptococcus mutans Biofilms-A Computational Approach to Confocal Image Analysis. DOI: 10.3389/fmicb.2022.880993 PMID: 35572682
- 14. Cannabinoid-Functionalized Glass Ionomer Cements: Structural Stability, Fluoride Release, and Antibiofilm Activity against Cariogenic Bacteria. DOI: 10.1021/acsomega.6c03572 PMID: 42626432
- 15. Low-Cost Active Thermography using Cellphone Infrared Cameras: from Early Detection of Dental Caries to Quantification of THC in Oral Fluid. DOI: 10.1038/s41598-020-64796-6 PMID: 32398732
- 16. Oral health in transition: The Hadza foragers of Tanzania. DOI: 10.1371/journal.pone.0172197 PMID: 28296885
- 17. US Department of Health and Human Services. The HIPAA Privacy Rule. 2024.
- 18. Legal Information Institute, Cornell Law School. 18 U.S. Code § 922: Unlawful acts. 2026.