Metronidazole and drinking 37 hours after?

Your dentist is wrong, it is 3 days.-72 hours.

What should I avoid while taking metronidazole?
Do not drink alcohol or consume food or medicines that contain propylene glycol while you are taking metronidazole. You may have unpleasant side effects such as headaches, stomach cramps, nausea, vomiting, and flushing (warmth, redness, or tingly feeling).

Avoid alcohol or propylene glycol for at least 3 days after you stop taking this medicine. Check the labels of any medicines or food products you use to make sure they do not contain alcohol or propylene glycol

Antibiotic medicines can cause diarrhea, which may be a sign of a new infection. If you have diarrhea that is watery or bloody, call your doctor. Do not use anti-diarrhea medicine unless your doctor tells you to.

https://www.drugs.com/metronidazole.html

There are 2 alcohol/food/lifestyle interactions with metronidazole which include:

Major
metroNIDAZOLE ↔ food
Major Food Interaction

Consumption of alcoholic beverages or products containing alcohol or propylene glycol during treatment with metroNIDAZOLE is not recommended. Doing so may occasionally trigger a reaction in some patients similar to the disulfiram reaction, which includes unpleasant effects such as flushing, throbbing in head and neck, throbbing headache, difficulty breathing, nausea, vomiting, sweating, thirst, chest pain, rapid heartbeat, palpitation, low blood pressure, dizziness, lightheadedness, blurred vision, and confusion. Rarely, more severe reactions may include abnormal heart rhythm, heart attack, heart failure, unconsciousness, convulsions, and even death. Patients treated with metroNIDAZOLE should continue to avoid using any products containing alcohol or propylene glycol for at least 3 days until after completion of therapy. Talk to your doctor or pharmacist if you have questions on how to take this or other medications you are prescribed. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Switch to professional interaction data

Moderate
High Blood Pressure (Hypertension)
Moderate Potential Hazard, High plausibility

metronidazole - sodium
Flagyl I.V. RTU (brand of metronidazole ready-to-use injection) contains 14 mEq of sodium per each 500 mg dose of metronidazole. The sodium content should be considered when this product is used in patients with conditions that may require sodium restriction, such as congestive heart failure, hypertension, and fluid retention.

References
"Product Information. Flagyl (metronidazole)." Searle, Skokie, IL.

https://www.drugs.com/food-interactions/metronidazole.html