For years, people have blamed sugar as the main reason behind cavities, but one dentist says the real cause might surprise you. According to the viral TikTok creator known as “The Bentist,” sugar itself doesn’t directly create cavities — bacteria in your mouth do.
The dentist explained that a bacteria called Streptococcus mutans feeds on sugar and then releases acid that weakens teeth, eventually causing decay. Without this bacteria, sugar alone wouldn’t damage teeth in the same way.
He also revealed that babies are born without cavity-causing bacteria. Instead, they often pick it up from parents or caregivers through everyday contact like kissing, sharing drinks, or tasting food with the same spoon.
That means oral health can partly be influenced by the “oral microbiome” passed down within families. Some people may naturally carry more harmful bacteria, making them more prone to cavities even if they don’t eat much sugar.
Interestingly, the dentist noted that this explains why some people rarely brush their teeth yet seem to avoid cavities, while others struggle despite good hygiene habits.
New research from the University of Alabama at Birmingham also found that children can pick up cavity-causing bacteria from classmates and friends, not just family members. Sharing food, drinks, or sweets can spread the bacteria between children.
Experts still stress that sugar plays a role because it feeds the bacteria, but maintaining good oral hygiene and regular dental care remain the best ways to protect your teeth.
The findings have sparked huge discussions online, with many jokingly blaming their parents for their dental problems after learning how cavities really develop.
