With her phone set to record in one hand and a hot pink nail file in the other, Mia Dio was ready to act on the “crazy idea” that had popped into her head just hours earlier.

“I’m going to file my teeth down with a nail file because they are not perfect,” Dio, 19, said in a video shared to TikTok in early June. “I have some ridges, and we’re ballin’ on a budget.”

Over the next 20 or so seconds, the Miami native chronicled portions of her foray into at-home dentistry, briefly showing footage of herself appearing to lightly drag a nail file back and forth across her two front teeth. At one point, she announced, “Guys, it’s literally working,” her voice tinged with excitement.

“It’s not perfect,” Dio said at the end of the video, providing a close-up look at her teeth. “But it is significantly better.”

The short clip, which has been watched more than 436,000 times, is one of the earliest documentations of what has become a trend on TikTok in recent months — much to the dismay of dentists who warn that the risky self-modification could cause lasting damage to teeth. Another similar video on the social media platform has garnered more than 8.4 million views as of Thursday morning.

Dio, a college student and self-described influencer, told The Washington Post she didn’t think her original TikTok would be seen by anyone.

“I was just kind of documenting my crazy idea that I had at 4 in the morning,” she said, referring to her efforts as an example of “quarantine DIY.” In the midst of the novel coronavirus pandemic, Dio said she was hesitant to go to the dentist for a noncritical procedure. So, she decided to take matters into her own hands.

“A lot of people started cutting their own hair, I became my own dentist,” she said.

But now, Dio and at least one other TikTok user who filmed a viral teeth-filing video are joining dentists in imploring people to leave their teeth alone.

“Don’t be a DIY dentist,” Dio said. “I got lucky. . . . Everything was fine for me. It isn’t necessarily going to be fine for the next person who tries.”

Aislinn Rendulic, 16, of Pennsylvania, said she learned that lesson the hard way.

An avid TikTok user, Rendulic said she was scrolling through the app last month when she came across a viral video of another young woman using a standard-looking nail file to shave down her front teeth. A couple weeks later, Rendulic said she thought of the TikTok as she laid in bed bored one night and decided to try it.

“I’ve always been a little bit insecure, because my teeth were slightly crooked,” she said. “I saw it as a simple fix to make them appear more straight.”

In her own TikTok video documenting the experience, Rendulic acknowledges that her actions wouldn’t be sanctioned by a dentist.

“I’m about to do something really dumb,” she says in the clip, which is captioned, “No one tell my dentist.”

At first Rendulic tries a foam nail file, but when that fails to produce results, she switches to a metal one.

“I’m scared,” Rendulic whispers before starting to file her top teeth again. Over the sound of metal scraping against enamel, she adds, “This can’t be good for my teeth.”

Yet, by the end of the ordeal, Rendulic appears mostly pleased with the results.

“It’s honestly probably impossible for you guys to tell, but it worked,” she says, letting out a happy-sounding squeal.

Rendulic told The Post she only filed her teeth for a short period of time and didn’t apply too much pressure, noting that the video’s audio made it seem “much more harsh than it actually was.”

What Rendulic didn’t film, though, was her subsequent attempt at filing. She said people had commented on her original video telling her to also do one of her bottom teeth that wasn’t perfectly aligned.

That turned out to be a mistake, Rendulic said.

“I probably filed it down way too much just because it was the most crooked, so I filed it until was in line with the rest of my teeth,” she said. Now, that’s the tooth causing Rendulic the most discomfort whenever she eats or drinks anything cold — a problem she said she didn’t have before filing her teeth.

Sensitivity is just one of the issues that can arise for people who try to even out their teeth themselves, said Zainab Mackie, a Detroit dentist.

Teeth have a thin, hard outer layer of enamel, Mackie said. The next layer is dentin, which is less dense than enamel and encases the pulp, the soft tissue that holds a tooth’s nerve center.

“When you file your nails, your nails grow back, but your teeth don’t,” she said. “That outer enamel layer doesn’t grow back. . . . Once it’s gone, that’s it.”

By grinding down your enamel and permanently removing the tooth structure, it’s easier to develop cavities and nerve damage, said Benjamin Winters, an orthodontist whose TikTok account, “The Bentist,” has more than 5.5 million followers.

“This trend is purely destructive against your teeth,” Winters said.

To avoid permanent damage or costly fixes, such as root canals, crowns, veneers and fillings, Mackie urged people to seek help from their dentists, who have the proper training to remove small amounts of enamel. The cosmetic procedure is known as enameloplasty.

“There’s so many times that my patients will ask me and I’ll be like, ‘Oh, I can do that really quick,’ and boom, we’re done in like two minutes,” Mackie said, noting that she does the simple procedure for free.

Winters, Mackie and other dental professionals have posted response videos on TikTok urging people not to use nail files on their teeth, no matter how minor the imperfection they are trying to correct may seem.

“Don’t get mad at me when your teeth are more sensitive than a 2-year-old crying over spilled milk, because I ain’t going to help you,” Winters says in one video. He later adds, “I can’t handle you guys anymore.”

Although Dio said she hasn’t experienced any negative side effects after filing down her teeth, she noted that she researched tooth sensitivity beforehand and was “extremely careful.” Still, if she had seen the warnings from dentists, which did not become widespread until after she posted her video, Dio said, “I probably would have thought twice about it.”

Meanwhile, Rendulic said she felt “instant regret” as she watched video after video of dentists and dental hygienists detailing the serious risks associated with at-home teeth filing. “It became really scary and real to me when I saw that,” she said.

Instead of hopping on the trend like she did, Rendulic said she hopes people will stop attempting DIY dentistry.

‘The videos I know are very enticing, and they make you want to try it because you see these instant results,” she said. “But it’s not worth it, and the pain you feel afterwards isn’t worth it, either.”

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