Fact File: The truth behind common dental myths

Anxiety, distrust and misinformation about dental care is abundant on social media, where posts containing false or out-of-context claims about dentistry can receive millions of views. 

The Canadian Press looked at several claims posted to social media in recent months that promote false, misleading or out-of-context information about dental care, and spoke to dentists about the truth behind common dental myths. 

CAN REMINERALIZING PRODUCTS CURE CAVITIES?

A TikTok video from November with around two million plays and more than 200,000 likes sparked discussion about cavities and whether some dentists push traditional fillings on patients who don’t need them. 

The video correctly claims hydroxyapatite toothpaste — which contains the same minerals that make up most of a tooth’s enamel, or outer layer — can reverse early tooth decay, and suggests the toothpaste works better than fluoride. 

Other social media videos promoting products containing hydroxyapatite suggest they can be used to treat deep or painful cavities. 

Dr. Aviv Ouanounou, an associate professor at the University of Toronto’s faculty of dentistry, said that while hydroxyapatite toothpaste works equally well to fluoride and can be a better option for children, it’s only beneficial in the early stages of tooth decay. 

That’s because there is a difference between cavities in the enamel and those in the softer layer beneath called the dentine. 

Ouanounou said hydroxyapatite toothpaste can help if someone has the early stages of a cavity in the enamel, because it contains minerals that can help reverse early decay. However, the toothpaste will not reverse a cavity that has reached deeper into the dentine. 

“Once you have a cavity, once it’s penetrated into the dentine, the tooth has to be drilled,” Ouanounou said. 

The TikTok says patients whose dentist recommends fillings for a small cavity should instead request Curodont, a product that attracts calcium and phosphate to help remineralize the tooth. 

Ouanounou said that similar to hydroxyapatite, using Curodont can help with remineralization in instances of early decay. 

“It cannot be used for a cavity that already developed into the dentine,” he said. 

He added that while hydroxyapatite and Curodont could be useful substitutes for patients who don’t feel comfortable with fluoride, there is no evidence that fluoride is harmful when used in the right concentration.

ROOT CANALS DO NOT CAUSE HEART DISEASE OR CANCER 

Some of the top comments on the TikTok video claimed the root canal — a dental procedure that removes infected tissue from the inside of a tooth — causes heart disease or cancer. 

Many cited “Root Cause” as the source of their claims, referring to the documentary decried by multiple professional dental associations for containing scientific misinformation; Netflix pulled the documentary from its streaming service amid the backlash. 

But the claims continue to proliferate, with videos and posts about the dental procedure's supposed link to disease and illness earning attention online. 

There is no scientific evidence behind the claim root canals cause serious illness, dentists told The Canadian Press. 

“The medical mainstream and dental communities overwhelmingly agree that the root canal treatment is safe, effective and eliminates pain,” said Dr. Annie Shrestha, an endodontist and assistant professor at the University of Toronto’s faculty of dentistry. 

She noted the root canal myths stem from the "focal infection" theory popularized in the early and mid-20th century, which claimed infections focused in one area could leak bacteria to the rest of the body and cause disease. 

However, dentists say decades of peer-reviewed studies have long since debunked the theory and its supposed relation to endodontic dental treatment like root canals. 

In 2019, the Canadian Dental Association and the Canadian Academy of Endodontics released a joint statement affirming the safety of root canals amid public misinformation about the procedure. The Canadian Cancer Society says there is no known link between root canals and cancer. 

DENTISTS ENCOURAGED TO ANSWER QUESTIONS HONESTLY

Dr. Bruce Ward, president of the Canadian Dental Association, said social media has created an influx of “armchair dentists” who come into their dental appointments with information that might not be true. 

He said he’s seen patients who resist root canals or repeat the claim that each tooth is connected to a specific organ through “meridian lines,” a concept that is not supported by scientific evidence but is frequently cited as fact on social media. 

The dentists who spoke to The Canadian Press emphasized the importance of conversations between patient and dentist that balance recognizing the scientific realities of dentistry with empathy and respect for patients, regardless of their beliefs. 

“People are scared. We have the cost, we have the fear and we have the social media, which puts a lot of wrong things in there ... Patients should ask their dentist, ‘What are the options?'” Ouanounou said. “And the dentist should answer honestly.”

“My assertion has always been that our mouth is our most private part,” Ward said. He described a patient whose wife of 20 years had no idea her husband wore a partial denture and was missing six front teeth. 

“People will walk in off the street and I’ll be looking in a place where maybe only two other, three other people have ever looked in there in that patient’s life,” he said.

There is a vulnerability among patients who might perceive dentistry as invading this privacy, he said. 

“It’s very valuable for the patient to have questions for the dentist, because that actually allows them to feel more comfortable about being worked on. It’s incumbent on the dentist to take the time to actually explain what they’re doing … and why they’re recommending what they’re recommending,” he said. 

This report by The Canadian Press was first published Dec. 19, 2025.