Cavities and Decay

Cavities do not always hurt, especially in their early stages, which is part of what makes them tricky to catch on your own. As decay progresses, though, most people start to notice one or more of the following signs. If any of these sound familiar, it is worth scheduling an exam rather than waiting to see if it goes away on its own.

• A visible dark spot, brown stain, or small hole on a tooth
• Sensitivity to hot, cold, or sweet foods and drinks
• A dull ache or sharp pain when biting down
• Pain that comes and goes without an obvious trigger
• A rough spot on a tooth that you can feel with your tongue
• Food that seems to get stuck in the same spot repeatedly
• Visible pits or grooves on the chewing surface of a tooth
• Bad breath or an unpleasant taste that does not go away with brushing

Cavities look a little different depending on age. In children, decay often forms in the deep grooves of the back molars, where food and bacteria collect easily and where brushing technique is still developing. Baby teeth also have thinner enamel than adult teeth, so decay can progress more quickly if it is not caught early, which is one reason we recommend starting checkups by a child's first birthday.

In adults, new cavities often appear between teeth or around the edges of old fillings and crowns, spots that are easy to miss without X-rays. Older adults face an additional risk, since gum recession can expose the root surface of a tooth, which is softer than enamel and more vulnerable to decay. Dry mouth, often a side effect of common medications, also becomes more common with age and further increases cavity risk in this group.

Tooth decay develops in stages, and understanding where a cavity falls on this spectrum helps explain why treatment can range from a simple filling to a root canal. The earliest stage is a white spot lesion, a small area where minerals have started to be lost from the enamel. At this stage, there is no hole yet, and with fluoride treatment and improved home care, this early damage can sometimes be reversed before it ever becomes a true cavity.

If the process continues, the enamel eventually breaks down enough to form an actual cavity, a small hole in the tooth's outer layer. This stage often has no symptoms at all, which is why it is usually caught on a routine X-ray rather than because a patient notices anything. Left untreated, decay then reaches the dentin, the softer layer beneath the enamel, where it spreads more quickly and often starts to cause noticeable sensitivity or mild discomfort.

Once decay reaches the pulp, the innermost layer of the tooth containing its nerve and blood supply, pain typically becomes much more obvious, often described as a persistent ache or sharp pain when biting down. At this stage, a simple filling is no longer enough, and root canal therapy is usually needed to remove the infected tissue and save the tooth. If an infected tooth is left untreated even longer, the infection can spread beyond the tooth itself, forming a painful abscess that may require more urgent care.

Tooth decay is caused by acid-producing bacteria that live naturally in everyone's mouth. When you eat or drink something containing sugar or starch, these bacteria break it down and produce acid as a byproduct. That acid attacks the minerals in your enamel, and over time, repeated acid attacks without enough recovery time in between will wear a hole through the enamel and into the tooth underneath.

While anyone can get a cavity, certain habits and conditions make decay more likely to develop and progress faster. Understanding your own risk factors can help you and our team decide how often you need checkups, X-rays, and preventive treatments like sealants or fluoride.

Diet plays one of the biggest roles in cavity risk, since frequent exposure to sugar and starch gives the bacteria in your mouth more opportunities to produce acid throughout the day. Sipping sugary drinks slowly over a long period, for example, can actually be worse for your teeth than drinking the same amount quickly, since it keeps your mouth in an acidic state for longer. Saliva also plays an important protective role, since it naturally neutralizes acid and washes away food particles, which is why conditions or medications that cause dry mouth tend to increase cavity risk significantly.

• Frequent snacking or sipping sugary or acidic drinks throughout the day
• Inconsistent brushing and flossing, or brushing technique that misses key spots
• Dry mouth, which reduces the saliva that naturally rinses away bacteria and acid
• Deep grooves or pits in the chewing surfaces of back teeth
• Old fillings or crowns with worn edges where bacteria can collect
• A diet high in refined carbohydrates and added sugar
• Not getting enough fluoride, whether from water, toothpaste, or professional treatments
• Age, since both young children and older adults face higher cavity risk for different reasons

A cavity does not stay the same size. Left untreated, decay continues to spread deeper into the tooth and can eventually reach the pulp, the soft tissue at the center of the tooth that contains its nerve and blood supply. Once decay reaches this point, a simple filling is no longer enough, and the tooth will likely need root canal therapy to remove the infection and save it.

If decay is allowed to progress even further, or if an infected tooth is left completely untreated, the infection can spread beyond the tooth itself, leading to an abscess, swelling, and in rare but serious cases, infection that spreads to other parts of the body. At that stage, extraction may be the only option, which means losing the natural tooth entirely and needing a bridge, implant, or denture to replace it.

Beyond the health risks, waiting also tends to cost more. A small cavity treated with a simple filling is one of the most affordable dental procedures there is. The same tooth, left untreated for a year or two, may need a root canal and crown, or even an extraction and replacement, all of which cost significantly more in both time and money than addressing the problem early. Treating a cavity as soon as it is found is almost always the simpler, faster, and more affordable path.

There is also a quality-of-life factor that is easy to overlook. A toothache from an untreated cavity can affect your ability to eat comfortably, sleep through the night, and concentrate at work or school. Addressing decay promptly is not just about protecting the tooth itself, it is about protecting your day-to-day comfort and well-being, and about avoiding the kind of emergency visit that is far more stressful than a routine filling appointment ever needs to be.

While no prevention routine eliminates cavity risk entirely, the following habits make a meaningful difference for patients of every age.