Tooth decay is the most common condition affecting teeth. It can cause pain, discomfort and affect eating, speaking and sleeping. The good news is that tooth decay is largely preventable.
Causes of tooth decay
Everyone has the bacteria that cause tooth decay living in their mouth. When you eat, the bacteria eat too. They feed on sugars in the food and drinks you consume, and produce acid, which damages the tooth surface (the enamel).
The tooth surface is also being constantly repaired. Saliva contains minerals that help repair the tooth surface. Fluoride, found in toothpaste and most of Victoria’s drinking water, also helps to repair damage. However, if over time there is more acid damage than repair, a cavity or ‘hole’ forms in the tooth surface.
Plaque and gum disease
Bacteria in the mouth create a sticky film called plaque. Gum disease is usually caused when plaque builds up on the gum line and the gum becomes inflamed. Gums may look red and swollen around the tooth. If not treated, the inflammation resulting from plaque can destroy the tissue fibres and bone that hold teeth in place. The things that help prevent tooth decay also help to prevent gum disease.
Preventing tooth decay
Everybody with teeth is at risk of tooth decay. You can lower your risk by:
- brushing teeth regularly
- using fluoride toothpaste
- limiting sugars (especially between meals)
- regularly having your teeth checked by a dentist or other oral health professional.
Regular tooth brushing helps prevent decay
While you can’t get rid of all the bacteria that cause tooth decay, it is possible to keep them under control. Regular tooth brushing helps to prevent tooth decay by sweeping bacteria and plaque off the teeth and gums.
Tips for tooth-brushing include:
- Clean your teeth and along the gum line twice a day; in the morning and before bed.
- Use a toothbrush with a small head and soft bristles.
- For children 0-18 months old, do not use toothpaste, only water.
- People over the age of 18 months should use a suitable fluoride toothpaste.
- Children 18 months to six years old should use a small pea-sized amount of low fluoride toothpaste.
- From six years of age, use standard fluoride toothpaste.
- Gently brush teeth and along the gum line in small circles.
- After brushing, spit out toothpaste, do not swallow it, and do not rinse with water.
- Help your child to brush until you are confident they can do it properly by themselves.
Limiting sugars helps prevent tooth decay
The bacteria that cause decay feed on the sugars (simple carbohydrates) from foods and drinks in the mouth. Often, these will be foods or drinks that taste sweet. However, highly processed foods may also contain sugars, even when they do not taste sweet.
If you eat less sugary foods and drinks, you give the bacteria less food to grow and multiply. Less bacteria will make less of the acid that damages the tooth surface.
Ways to reduce your sugar intake:
- Follow the Australian Dietary Guidelines and eat a wide variety of nutritious foods from the five food groups every day: vegetables, fruit, grains, lean meats (or alternatives) and dairy (or alternatives).
- Limit sugary foods, especially sticky foods that stay on the teeth.
- Limit sugary and acidic drinks such as soft drinks (including sugar-free/diet and regular), sports drinks, cordials and fruit juices.
- Ask about medication – check if any of your medication has sugar in it and if there is a sugar-free alternative. Also ask if your medication has an effect on saliva.
Chewing sugar-free gum can also be helpful in the fight against decay. It can help to produce saliva, which is able to wash sugar out of the mouth into the stomach, neutralise acid, fight bacteria and repair the early stages of tooth decay.
Fluoride helps prevent tooth decay
Fluoride helps to repair damage to the tooth surface. Fluoridated drinking water and toothpastes have reduced the amount of tooth decay in Australia.
Use a suitable fluoride toothpaste:
- Use only water to brush the teeth of children under 18 months old.
- Use low fluoride toothpaste for children 18 months up to six years of age.
- People six years and older can use standard fluoride toothpaste.
Drink plenty of water – fluoride is found in most of Victoria’s tap water and helps to repair acid damage to teeth. Water also helps to wash away sugars from food and drink and dilute acid in the mouth.
If you live in a community where the water is not fluoridated, talk to your oral health professional to make sure you are getting the right amount of fluoride to help prevent tooth decay. Your local water authorities can tell you if fluoride is added to your water supply. You can also search by postcode on the Department of Health website.
Dental check-ups help prevent decay
It can be difficult to see the early signs of tooth decay. An oral health professional can help to spot and treat any problems early. Ask your oral health professional how often you should have a dental check-up.
All children should have an oral health assessment by the time they turn two. This may be done by an oral health professional such as a dentist, or other health professional such as a maternal and child health nurse or your doctor.
Always see your oral health professional if you have:
- mouth pain
- bleeding gums
- swelling of the face
- damaged or knocked out a tooth
- sores that don’t heal after a couple of weeks.
Other tips for a healthy mouth
- Quit smoking to improve oral health and general health. Smoking is one of the main risk factors for oral cancers.
- Limit your alcohol intake. Alcohol is also a risk factor for oral cancers.
- Protect your face from the sun. Use an SPF30+ broad spectrum, water-resistant sunscreen to reduce the risk of lip cancers.
- Wear a mouthguard when playing and training for sport if there is a risk of mouth injury. For some sports you will need a full-faced helmet or face guard.
Where to get help
- Your maternal and child health nurse
- Community dental clinics:
- The Royal Dental Hospital of Melbourne:
- General enquiries or to make an appointment Tel. (03) 9341 1000 or 1800 833 039 outside Melbourne metro 8.30 am to 5 pm, Monday to Friday
- Dental emergencies Tel. 1300 360 054 8.30 am to 9.15 pm, Monday to Friday, 9 am to 9.15 pm, weekends and public holidays
- Your private dental clinic:
- Psychologist, to help with stress management
Things to remember
- Tooth decay is caused by acid damage from bacteria over time.
- Brushing twice a day is important for preventing tooth decay. People over 18 months of age should use fluoride toothpaste.
- Avoiding sugary foods and drinks, and drinking plenty of tap water (especially if fluoridated) also helps to prevent decay.
This page has been produced in consultation with and approved by:
Dental Health Services Victoria
Content on this website is provided for education and information purposes only. Information about a therapy, service, product or treatment does not imply endorsement and is not intended to replace advice from your doctor or other registered health professional. Content has been prepared for Victorian residents and wider Australian audiences, and was accurate at the time of publication. Readers should note that, over time, currency and completeness of the information may change. All users are urged to always seek advice from a registered health care professional for diagnosis and answers to their medical questions.