Teeth

Image: Dental Health Services Victoria

A person has two sets of teeth over their lifetime – baby teeth (also known as deciduous, primary or milk teeth) and adult (secondary or permanent) teeth. Baby teeth usually start to appear at about six months of age and children usually have their full set of 20 baby teeth by age three.

From about six or seven years of age, some baby teeth start to fall out and are slowly replaced by the adult teeth. By around 21 years of age, the average person has 32 adult teeth (which includes 4 wisdom teeth); 16 on the top and 16 on the bottom. Some people have less or even more than this number of teeth, which you can discuss with your oral health professional.

The health of your mouth is an important part of your overall health. Diseases in teeth and gums can affect other parts of your body, including the heart.

Role of teeth

Teeth play an important role in eating, chewing and nutrition. They are different shapes and sizes to bite, tear, crush or grind food before it is swallowed. They also help us to form sounds and speak clearly, and they are an important part of a person’s smile. In this respect, teeth can be associated with a person’s confidence and social interaction.

Baby teeth also play an important role in holding space for the adult teeth. For these reasons it is important to keep them healthy and prevent the early loss of these teeth due to disease.

Parts of the tooth

Your teeth are made up of the following parts:

• crown – the part of the tooth that sits above the gum line
• enamel – the hard, smooth, white outer layer that protects the crown. Enamel is harder than bone and doesn’t have any nerves or a blood supply. Chipped or decayed enamel cannot grow back and may lead to further decay or wear.
• dentine – the middle layer under the enamel. If the enamel is damaged or decayed and the underlying dentine is exposed, the tooth can be sensitive to temperature and sweet or acidic foods.
• pulp – the living centre of the tooth containing blood vessels and nerves. The nerve provides the sensation of temperature, pressure and pain.
• root – the section of tooth that is usually below the gum line within the bone of the jaw. Different teeth can have one or many roots where nerves and blood vessels pass in and out of the pulp.
• cementum – a material that covers the root surface.

Teeth and eating

Teeth help us to eat by breaking food into smaller pieces so that it can be swallowed and digested. Over time, teeth can get worn down from normal and abnormal use.

Teeth have different shapes to do different jobs. Types include:

• incisors are front teeth which bite together like a pair of scissors. There are 4 upper and 4 lower incisors each in the baby and adult sets of teeth.
• canines are pointy shaped teeth (sometimes called fangs or eye teeth) just back from the incisors, which are used to tear food. There are 2 upper and 2 lower canines in the baby and adult sets of teeth
• premolars are between the canines and molars and help crush food. There are 4 upper and 4 lower adult premolars. There are no premolars in the baby teeth.
• molars are the back teeth, larger than premolars with big flat surfaces to grind food. There are six upper and six lower adult molars, and four upper and four lower molars in the baby teeth.

Caring for teeth

Teeth are important for eating, speaking and socialising, so it’s important to take good care of them.

Some tips include:

• Brush twice a day, in the morning and at night before bed - use a toothbrush with a small head and soft bristles. Gently brush your teeth and along your gum line, making sure to brush each tooth on the front, back, and top.
• Start toothbrushing from the first tooth - use toothbrushes with a small head and soft bristles. You can also use a wet cloth to wipe over teeth and gums for babies. Only use water to clean your baby’s teeth and gums until they are 18 months of age. Use age appropriate tooth brushes as you get older.
• From 18 months of age, use fluoride toothpaste - use a low-fluoride children’s toothpaste for children aged 18 months to six years, and standard fluoride toothpaste for from age six years and older.
• Avoid sugary, acidic or carbonated (fizzy) foods and drinks - watch out for sweet and sticky foods, soft drinks, fruit juices, energy drinks and even diet ‘no sugar’ carbonated drinks which can cause tooth decay in excess. If you do have these, it is better to have them at mealtimes rather than between meals.
• Drink plenty of tap water - most of Victoria’s has fluoridated tap water, which helps repair the tooth surface. If your water is not fluoridated (eg tank water), talk to your oral health professional about how to you can get the right amount of fluoride to best protect your teeth.
• Have a regular check-up - regular check-ups are important for identifying and treating any issues before they become bigger and harder to treat. There are also a number of treatments which help to prevent disease. Ask your oral health professional how often you should have a dental check-up.
• Wear a mouthguard when you train for and play sports where your teeth could get damaged - for example football, rugby, soccer, basketball, netball, water polo or hockey.
• Wear an occlusal splint or night guard at night if you have habits such as clenching or grinding of teeth - such habits can cause teeth and fillings to wear down, fracture, and be sensitive or even split in half.
• Quit smoking to improve your oral health and general health.

Tooth conditions

Some examples of problems that can affect the teeth include:

• tooth decay
• gum disease
• loss of the tooth surface (enamel) through:
  • /node/1124 (caused by acids from food and drinks, or acids coming up from the stomach)
  • dental abrasion (often due to incorrect or forceful tooth brushing)
  • dental attrition and abfraction (often due to grinding or chewing)
• tooth and jaw alignment problems such as crooked, crowded or overlapping teeth
• tooth grinding (bruxism)
• tooth trauma, such as a broken or knocked out tooth
• developmental defects of the teeth such as ‘chalky teeth’ (molar hypomineralisation)

Where to get help

• Your oral health professional (Dentist)
• Dental Health Services Victoria provides public dental services through the Royal Dental Hospital Melbourne and community dental clinics, for eligible people. For more information about public dental services Tel. (03) 9341 1000, or 1800 833 039 outside Melbourne metro
• Australian Dental Association ‘Find a Dentist’ search function or Tel. (03) 8825 4600
• Maternal and child health nurse
• Your GP (doctor)