Most people assume that taking care of their teeth means brushing twice a day and seeing a dentist occasionally. But dental professionals say the habits most likely to cause lasting damage are often the ones people do not associate with oral health at all. Chewing on pens, brushing too aggressively, breathing through the mouth and reaching for whitening strips too often are all capable of eroding enamel, creating fractures and triggering long-term sensitivity. Here is what dentists say to stop, and why it matters more than most people realize.
Chewing on hard objects
Crunching ice, biting fingernails and chewing on pen caps all seem like low-stakes habits. Over time, they wear down enamel and create small fractures in the tooth structure that worsen with continued pressure. Those fractures, left unaddressed, can eventually require crowns or root canals. Keeping something soft nearby, such as sugar-free gum, can help redirect the urge, particularly in moments of stress or distraction.
Using teeth as tools
Teeth are designed for eating, not for prying open packages, twisting off bottle caps or tearing through tape. The force and angles these tasks require can chip, crack or fracture teeth, especially the front ones. Beyond structural damage, the objects commonly held in the mouth this way are often covered in bacteria, increasing the risk of infection. Structural damage from this habit, once it occurs, is largely irreversible and may require crowns or veneers to correct.
Mouth breathing
Breathing through the mouth rather than the nose bypasses the filtering and humidifying function that nasal breathing provides. Over time, mouth breathing reduces saliva production, which the mouth depends on to neutralize acids and protect against bacteria. The result is a higher risk of enamel erosion, cavities and gum inflammation. In children, chronic mouth breathing can also affect facial development and lead to orthodontic complications. Dentists recommend identifying the underlying cause, which is often allergies, nasal obstruction or sleep-disordered breathing, and addressing it directly.
Overusing whitening products
At-home whitening products used too frequently or without professional guidance can thin enamel, irritate gums and cause persistent sensitivity. Sudden sensitivity to hot or cold drinks after whitening is a warning sign that the products are causing harm rather than just cosmetic improvement. In more serious cases, overuse can lead to gum recession or enamel damage that requires bonding or veneers to repair. Dentists recommend using these products under professional supervision and following recommended frequency guidelines carefully.
Frequent snacking and teeth grinding
Every snack, particularly those high in sugar or refined carbohydrates, feeds the bacteria in the mouth and produces acid that attacks enamel with each exposure. Snacking throughout the day instead of at set meal times keeps that acid cycle running continuously. Limiting snacks to defined windows and choosing tooth-friendly options like cheese, nuts and raw vegetables gives enamel more time to recover between exposures.
Nighttime teeth grinding, known clinically as bruxism, is another habit many people are unaware they have. It can gradually flatten biting surfaces, cause fractures and lead to jaw pain or temporomandibular joint discomfort. Because enamel does not regenerate once it is worn away, the damage from grinding is cumulative and permanent. A custom-fitted night guard, along with stress management and limiting caffeine and alcohol, is the most effective protective measure available.
Brushing habits that cause more harm than good
Brushing harder does not mean brushing more effectively. Excessive pressure wears down enamel and exposes the softer dentin layer underneath, increasing sensitivity and accelerating decay. Dentists recommend a soft-bristled toothbrush used in gentle circular motions rather than a back-and-forth scrubbing motion. The pressure required to remove plaque is far less than most people apply.
Equally counterproductive is brushing immediately after eating. Meals lower the mouth’s pH, temporarily softening enamel. Brushing before that enamel has had time to reharden, a process saliva facilitates naturally over about 30 minutes, accelerates wear rather than preventing it. Brushing before breakfast or waiting at least half an hour after eating is the more protective approach.
The case for flossing
Skipping floss allows plaque and food particles to accumulate in the spaces between teeth and beneath the gumline, areas a toothbrush cannot reach. Over time this leads to gum inflammation that, without intervention, progresses to recession and more serious periodontal disease. Early gum inflammation can be reversed with professional cleaning, but tooth decay that develops in neglected interdental spaces requires fillings, crowns or root canals.
Dentists recommend flossing once daily with traditional waxed string floss, which moves easily between tight teeth. Floss picks, while less thorough, are a practical alternative for anyone who finds string floss difficult to use consistently.
The underlying message across all nine habits is the same. Teeth are durable but not indestructible, and the most significant damage tends to accumulate slowly from things people do every single day without a second thought. The earlier those habits are identified and corrected, the less costly the consequences.
