KEY POINTS
- A tooth (dental) cavity is a hole in the tooth caused by tooth decay.
- Once the decay has reached the dental pulp, it is permanently damaged and requires treatment by a dentist to be filled.
- Early stages of tooth decay are potentially reversible through remineralisation, using minerals from saliva and fluoride.
- Brushing and flossing regularly, drinking fluoridated water, avoiding sugar and regularly visiting the dentist is the best ways to prevent tooth cavities and potentially repair early signs of tooth decay.
It’s easy to get confused about tooth decay and cavities (aka caries), especially if you’ve heard that some tooth decay is reversible. You may wonder, does that mean cavities can be healed naturally, too? Sadly, you can’t reverse cavities — not once they have found their way below the enamel and into the dentin, the softer substance that sits below the enamel. But if you catch dental decay in its early stages, it can be reversed and healed.
Here’s what you need to know.
What happens inside our mouths
Our mouths are full of bacteria. Hundreds of types live inside our teeth, gums, tongue and other places in our mouth. While some bacteria are helpful, others are harmful and play a role in tooth decay.
Tooth decay results from an infection with certain bacteria that use sugars in food to make acids. Eventually, these acids can make a small hole or cavity in the tooth. Day and night, there is an ongoing tug-of-war in our mouths.
On one side, let’s call it Team Dental Plaque. Dental plaque is a sticky, colourless film of bacteria and sugars from sugary foods and drinks we’ve ingested. The bacteria feed off the sugars and produce acids, which eat their way through the tooth’s hard outer surface, known as the enamel.
On the other side, let’s call it Team Minerals. This team consist of the minerals in our saliva (like calcium and phosphate) and fluoride from fluoridated water, toothpaste and other sources. They help repair the tooth enamel by replacing minerals depleted due to an ‘acid attack classical quote.
This tug-of-war battle between dental plaque and minerals goes on all day and night, with our tooth enamel losing and gaining minerals.
How does a cavity develop?
If you eat and drink lots of sugars and fail to follow good oral hygiene, you lose the tug-of-war to Team Plaque. The dental plaque begins to decay the enamel. Sometimes, you’ll notice a white spot on the tooth. This is a sign of early tooth decay, which, at this stage, is reversible.
Suppose you fail to take action by avoiding sugars, rinsing your mouth regularly with fluoridated water, brushing with fluoridated toothpaste — and possibly visiting your dentist for a fluoride treatment. In that case, eventually, you’ll form a tooth cavity. Once you have an established cavity that has eaten its way through the enamel, it cannot be reversed and must be filled by the dentist.
Tooth decay stages
Learning the stages of tooth decay will help you understand why fully developed cavities are not reversible while early stages of tooth decay are.
1. Demineralisation: During this stage, you might notice small white, chalky spots on your tooth — due to the breakdown of minerals in your enamel.
2. Enamel decay: If you continue to lose the ‘tug-of-war’, the tooth decay progresses and breaks down your enamel. Small holes or cavities may become noticeable, and white spots may turn to a light brownish colour.
3. Dentin decay: Underneath your tooth enamel lies a layer called dentin. It is much softer than your enamel, so once the bacteria and plaque reach this layer, cavities form faster. You may notice some tooth sensitivity at this stage, and the white spots may turn a darker brown.
4. Pulp damage: Your tooth pulp is the most central layer of your tooth. It contains nerves and blood vessels; when cavities reach your pulp, you may feel pain. You might also start to notice redness and swelling in nearby gums.
5. Abscessed tooth: If your cavity has not been treated, it may become a deep cavity, which can cause an infection. This infection can cause a pocket of pus at the very tip of your tooth root called a periapical abscess. Symptoms may include pain, facial swelling and swollen lymph nodes on your neck. Abscessed teeth must be taken seriously as the infection can spread to other areas of your body.
differences between pre-cavities & cavities
PRE-CAVITY
- Damaged enamel
- Reversible
- No holes (but may have visible white spots)
- Usually not painful
CAVITY
- Damaged enamel and dentin
- Irrevarsible
- Presence of holes
- Painful
How to win the cavity tug-of-war
Drink fluoridated water and use fluoridated toothpaste.
Fluoride helps to prevent mineral loss and replaces lost minerals. It also reduces the ability of bacteria to make acid. Your dentist may also recommend fluoride treatments during your regular scale and clean to protect your tooth enamel further.
Watch what you eat and drink
Limit snacks between mealtimes and avoid sugary food and beverages. Also, make sure you don’t eat or drink anything other than water after you brush your teeth in the evening.
Discuss sealants with your dentist
Your dentist may recommend using sealants on your children’s teeth to protect them from cavities further. Sealants are a thin, plastic coating painted onto the surfaces of the back of teeth, giving them further protection against tooth decay.
Have regular dental check-ups and cleans
Regular dental exams, scale and cleans (preventative dental) will help look out for the early stages of dental caries, as well as give your teeth a good clean to remove plaque. Often, you’ll also receive a fluoride treatment to help seal your enamel and further prevent decay.
When to call a dentist
If you have any of the following symptoms, you must contact your dentist:
• difficulty chewing
• signs of infection (redness, pain, swelling)
• a swollen face
• toothache or pain in the mouth
• bleeding gums
• a brown or black patch on the tooth
• fever
What do cavities feel like? And other FAQS
Suppose your tooth decay or dental cavity is in its very early stages (meaning it hasn’t spread beyond your enamel yet). In that case, you may be able to reverse cavities or decay by re-mineralising your teeth with fluoride treatments and improving oral hygiene.
NB: If the cavity has spread below the enamel and into your dentin, you will need professional treatment such as a filling, crown or other dental restoration
You won’t feel anything in the early stages of tooth decay (such as a small cavity that only affects your enamel). However, once the decay reaches your tooth’s inner layers, you may feel pain or sensitivity to hot or cold foods and beverages.
Tooth cavities become larger over time. As the decay worsens, it enters the deeper layers of your tooth, which can result in pain, infection and tooth loss. This is why you must see a dentist if you think you may have a dental cavity.
If your dental cavity is causing pain, it has likely spread to deeper layers of the tooth. At this stage, you must see a dentist to repair the cavity. If you catch it early enough, a dental filling will suffice. However, suppose it has advanced and has caused infection. In that case, you may require root canal treatment or an extraction (as a last resort).
In the early stages of dental decay, you may notice small, white, chalky spots on your tooth enamel. As the cavity progresses, you may see brown or black spots on your tooth.
Tooth decay in Australia is exceedingly common, but that doesn’t mean it shouldn’t be seriously addressed. One in three strain adults over the age of 15 years has untreated tooth decay. And, by five years of age, one in three children has tooth decay in their baby teeth.
