By David MH Lambert, DDS
Half of dentists say patients show up to appointments high. In an ADA survey, 52 percent reported it, 56 percent said they limited treatment because of it, and 46 percent had to increase anesthesia to get through the visit. And more dentists report it every year.
So where is the guidance? In 2021 the ADA House of Delegates passed a resolution encouraging the development of best practices for managing patients under the influence. Then it declined to write them, citing limited data. Five years on, that is still the posture.
That leaves you alone in the operatory with a patient who used before the visit and no standard to lean on. I got tired of waiting, so I wrote one.
The principle the whole thing rests on
Use is not impairment.
A patient can use cannabis and be perfectly fit to treat. A patient can also be impaired and unable to consent. Those are two different findings, and a good policy keeps them apart. Odor, a positive test, or a medical card all tell you the patient used. None of them proves the patient is impaired right now. THC lingers for days, so a positive test only tells you the patient was exposed at some point.
What you can do is assess the person in the chair and act on what you observe and measure. The ADA agrees on this much: cannabis use by itself does not establish incapacity, and a capacity assessment is required.
What a real office policy has to handle
Start at the front desk. A cannabis history belongs on your health questionnaire, asked the same neutral way you ask about tobacco and alcohol, including whether the patient holds a medical card and which state issued it. Read that card as a clinical flag. A cardholder is usually a chronic, high-potency user, and that shifts sedation and cardiac risk.
Then the smell. Odor in a crowded reception area is a prompt to investigate, and it is never a reason to confront anyone in public. Bring the patient back before you ask a single question. And remember your team: secondhand cannabis smoke in a closed waiting room is a real occupational exposure your staff should not have to breathe.
The hard cases give off nothing. A vape pen barely smells. An edible does not smell at all, and it peaks late, so a patient who looked fine at check-in can slide deeper 30 minutes into your procedure. When you cannot smell it, you stack pointers: an honest history, your practice’s base rate, signs of intoxication, and the mouth itself, which records chronic use in xerostomia-driven caries, periodontal breakdown, and acid erosion.
Check vitals, including heart rate. THC drives tachycardia and raises myocardial oxygen demand, and the risk of a heart attack spikes in the first hour after use. A 2025 analysis found cannabis users under 50 with no traditional risk factors were over six times as likely to have a heart attack. That is the window to delay elective care rather than push through it.
Close the loop with your staff. The most dangerous failure is silent: someone smells cannabis and does not tell you until after sedation has started. Make it a rule that anyone who notices reports it before treatment, every time, and that you confirm you heard it.
Then document. Chart the behavior you observed, the vitals, the patient’s own words, and the decision you made because of them. Never chart a conclusion like “patient was high” that you cannot prove.
Two tools to make this practical
I built two things you can put to work today.
The first is a one-page chairside decision algorithm your whole team can follow: trigger, privacy, history, vitals, assess impairment, then proceed, defer, or refer. Print it and pin it in the operatory.
The second is an adoptable office cannabis policy template. Fill in your practice name and state, adapt the language, and you have a written standard for how you treat the cannabis patient and protect your team.
One caveat, and I will repeat it because it matters. Whether you can refuse a lawful cardholder, discipline an employee, or write a blanket rule is state-specific and unsettled. Know your own state’s program, and run the finished policy past your own attorney before you adopt it.
Organized dentistry left the gap. You do not have to stand in it unarmed. Put a written policy in place.