Does Vitamin C and Caffeine Affect Local Anesthesia Before a Dental Procedure?

Regular visits to a dentist are part of having good oral health and will aid your overall health. But a post on the social media sharing site TikTok has some people wondering about their safety during that dental visit. TikTok is full of cautionary tales, most have little or no scientific evidence to support their cautions—like the woman who claimed that pregnancy made her teeth decay and break off. There's also a post about avoiding caffeine and vitamin C before a dental procedure to avoid facial paralysis. We wanted to see if that was legit advice.

The Story of Bethy.Bee

One woman, known as @3ethy or Bethy.Bee, recently shared her story of dental work gone wrong after she ended up with half of her face "nearly paralyzed" from too much local anesthesia. "A little word to the wise: Don't take any vitamin C or drink any caffeine before your dentist appointment," she said. "They may have a hard time numbing you and you'll end up with half your face nearly paralyzed and still no work done 'cause you could still feel it."

In the video, which has been viewed more than 5.2 million times and has received 1.8 million likes, Bethy.Bee said that she couldn't even blink her eye after the mishap. "I have to manually shut it. Craziest thing ever," she said, adding that she'd have to visit the dentist again in three weeks for another attempt at the procedure.

Luckily, Bethy.Bee was fine by the next day and shared an update with her TikTok viewers, saying she had "full facial movement and automatic blinkers" by then. She also shared with viewers that she is "notoriously hard to anesthetize" and that "caffeine and vitamin C can react negatively with anesthesia."

No Evidence To Avoid Vitamin C Before Dental Work

If vitamin C is taken before local anesthesia is administered it may decrease effectiveness, but there's little scientific data to back this up, John Luther, DDS, Chief Dental Officer at Western Dental & Orthodontics, tells Health.

"I don't believe there is any credible evidence for this," agrees Charles D. Azzaretti, DDS, Program Director of Dental Anesthesiology at NYU Langone Dental Medicine. "I was not able to find anything in the scientific literature that supports the theory."

Dr. Azzaretti tells Health that some dental practice websites offer an explanation for the interference of vitamin C in the action of local anesthesia in the dental setting. They claim that lowering the pH interferes with the onset of a local anesthetic and since vitamin C (ascorbic acid) is acidic, it could interfere with the onset of a local anesthetic.

But Dr. Azzaretti describes this as a "false inference," since even very large doses of vitamin C after ingestion would be diluted, buffered, and excreted. "It would have no appreciable effect on the pH of the tissues associated with the dental alveolar structures (tooth sockets)," Dr. Azzaretti explains.

If taken after surgical procedures, vitamin C has many great qualities including reducing healing time, Dr. Luther adds.

Should I Avoid Caffeine?

Again, it's difficult to establish a direct effect between caffeine and the administration of local anesthesia, but Dr. Luther says many dentists feel that caffeine decreases the effectiveness of local anesthesia administered for dental procedures.

"Caffeine is known to heighten awareness and in high doses may increase a patient's anxiety or make them nervous during dental treatment, affecting the patient's experience whether or not anesthesia is given," he explains.

Dr. Luther says that taking a dietary supplement thought to have a calming effect, such as St. John's Wort, might strengthen the overall effect of local anesthetic and improve the patient experience.

What Affects Local Anesthesia

Potentially many things can affect how you react to local anesthesia says Dr. Azzaretti.

• The presence or absence of infection
• If you have inflammation
• Your level of pain threshold—which can vary greatly between patients
• Patient anxiety associated with oral injections—and with dental treatment in general
• Different injection approaches—such as blocks or infiltration
• The ability of the patient to metabolize the local anesthetic

Occasionally, local anesthesia may be injected in a spot that does not completely numb or blocks a nerve in the lower jaw, which leads to decreased effectiveness, Dr. Luther says.

"Personally, I think operator accuracy, thoroughness, and patience is the most important variable," Dr. Azzaretti says. "But I believe any of the above variables alone would be at least as significant—and probably more—in achieving effective local anesthesia than if the patient had several cups of coffee prior to the procedure."

The bottom line: If you have a cup of coffee or a glass of orange juice before your next cleaning, you should be totally fine. But if you're extra anxious, go ahead and skip the drinks if you want.