9 Habits That Are Ruining Your Teeth, According to Dentists

Chewing on Hard Surfaces

Chewing on pen caps, biting your nails, or crunching ice might seem harmless, but over time, these habits can seriously damage your teeth. “The habit wears down enamel and can create tiny fractures that worsen over time,” says Dr. Nicole Khalife, DDS, general dentist and dental practice owner at Lux Smiles NYC, potentially leading to the need for crowns or even root canals.

If you tend to chew when stressed or distracted, Dr. Khalife suggests keeping something soft nearby, like sugar-free gum, to help redirect the urge. “With kids and teens, I’ve had success recommending fidget tools to help break nail-biting cycles.”

Using Your Teeth as Tools

Similarly, using your teeth to open packages or twist-off bottle caps can backfire, as teeth aren’t designed to handle the force or angles tools require. This can lead to chips, cracks, or fractures, especially in the front teeth.

“Accidental slipping when using teeth as tools can result in lacerations or irritation to the gum,” says Dr. Jie Sun, DMD, MMSc, FACP, lead prosthodontist at ClearChoice. “Oftentimes, the objects we put in the mouth are full of bacteria, which may also increase the risk of infection and cause germs to enter into our system through the mouth.”

Once structural damage like deep fractures, enamel loss, or loosening of dental restorations happens, it’s irreversible and may need extensive dental work like crowns or veneers. “Bottom line: teeth are for eating—not for functioning as tools,” says Dr. Sun. “Keeping this habit in check helps protect your tooth structure, preserve existing dental work, and support your overall oral and systemic health.”

Mouth Breathing

Breathing through your mouth can harm your oral health over time. Without enough saliva to neutralize acids, your mouth becomes prone to enamel erosion, cavities, and gum inflammation.

“Additionally, mouth breathing may also impact facial development in children and lead to orthodontic issues,” says Dr. Sun. “Unlike nasal breathing, which filters, warms, and humidifies the air, mouth breathing inhales unfiltered air, which often contains more dust, allergens, and pathogens, to enter the body directly.” This unfiltered air can irritate airways and raise the risk of inflammation or infection, especially if your immune system is compromised.

“The key to treating mouth breathing is identifying the underlying cause and patient education,” Dr. Sun adds, noting allergies, nasal obstruction, and sleep-disordered breathing as common triggers. Restoring nasal breathing helps reduce mouth breathing.

Overusing Whitening Products

While at-home whitening products are convenient, Dr. Khalife recommends using them under professional supervision. “Excessive whitening, especially with store-bought gels or strips, can lead to enamel thinning, sensitivity, and irritated gums,” she says.

Overusing whiteners can cause more than temporary discomfort. It may lead to permanent sensitivity, gum recession, or even require bonding or veneers to repair the damage. “If your teeth suddenly become sensitive to cold or hot drinks, or if your gums sting after whitening, that’s a red flag,” says Dr. Khalife.

Frequent Snacking

Frequent snacking without proper care can lead to cavities, gum inflammation, and enamel wear, and over time, more serious issues like gum recession or even root exposure. “Every snack, especially ones high in sugar or carbs, feeds the bacteria in your mouth. They create acid that attacks your enamel,” says Dr. Khalife.

Bleeding gums, sudden sensitivity, or white spots near the gumline can be early warning signs. To protect your teeth, Dr. Khalife suggests limiting snacks to a few set times during the day and choosing tooth-friendly options like cheese, nuts, or raw veggies.

Teeth Grinding

You might not realize it, but nighttime teeth grinding can gradually wear down enamel. Over time, it can flatten biting surfaces, cause fractures, shorten teeth, and lead to gum recession or temporomandibular joint pain, known as TMJ pain, which is discomfort or soreness in the jaw joint and surrounding muscles. In severe cases, it may even result in tooth loss.

“Unfortunately, enamel does not regenerate, and once teeth are ground down, they do not heal themselves,” says Dr. Sandip Sachar, DDS, dentist and owner of Sachar Dental. Along with stress management, limiting caffeine and alcohol, and regular dental checkups to monitor any changes, she recommends a custom-fitted night guard for teeth grinders.

Brushing Too Hard

Brushing harder doesn’t mean brushing better, as too much pressure can wear down your enamel, exposing the softer dentin beneath. “When enamel is eroded, it can cause cracking, chipping, and fractures, along with increased sensitivity and faster tooth decay,” says Dr. Sachar.

To prevent this, use a soft-bristled toothbrush and adjust your technique. “I recommend brushing in a gentle, circular motion, versus sawing back and forth,” Dr. Sachar advises. She adds that plaque is soft, so there’s no need to scrub hard. “Let the bristles do the work.”

Brushing Right After Breakfast

Brushing right after a meal might seem like a good idea, but it can wear down enamel faster. Eating lowers your mouth’s pH, making it more acidic and softening the enamel. “When you brush immediately after a meal, the mechanical abrasion from brushing can accelerate enamel wear,” explains Dr. Sun. “Over time, this can lead to increased tooth sensitivity, a higher risk of caries, and visible changes such as dullness, shortening of teeth, and enamel thinning, resulting in an overall less desirable appearance.”

To protect your enamel, Dr. Sun recommends brushing before breakfast or waiting at least 30 minutes after eating. “Saliva helps neutralize acids and remineralize enamel. Giving it at least 30 minutes before brushing allows saliva to restore the natural pH balance in your mouth, reducing the potential mechanical damage from brushing.”

Not Flossing Enough

If flossing often falls off your daily list, it’s worth reconsidering. Skipping floss lets plaque and food particles build up between teeth and under the gumline, areas your toothbrush can’t reach. This buildup can cause gum inflammation and, over time, gum recession.

While early gum inflammation can be reversed with professional cleaning, tooth decay isn’t reversible and requires treatments like fillings, crowns, or root canals. To protect your oral and overall health, Dr. Sachar recommends flossing once a day with traditional waxed string floss, which slides easily between tight teeth. “For people who do not like using string or ribbon dental floss, floss picks offer an alternative that leads to increased compliance with flossing. While not as effective as string floss, they are better than not flossing at all.”