The hard, outside covering of your teeth is called enamel. Enamel
is very hard, mainly because it contains durable mineral salts, like calcium.
Mineral salts in your saliva help add to the hardness of your teeth. Mineral
salts, however, are prone to attack by acids. Acid causes them to break down.
For an experiment about the power of acid, check out the Healthy
Teeth Dental Experiments page!
The plaque that forms on your teeth and doesn't get washed away by
saliva or brushed away by your toothbrush produces acid as it eats up sugar.
This acid is produced inside the plaque and can't be easily washed away by your
saliva. The acid dissolves the minerals that make your tooth enamel hard. The
surface of the enamel becomes porous - tiny holes appear. After a while, the
acid causes the tiny holes in the enamel to get bigger until one large hole
appears. This is a cavity.
It's important to see your dentist before a cavity forms so that
the plaque you can't reach with your toothbrush or floss can be removed.
Your mouth is a busy
place. Bacteria - tiny colonies of living organisms are constantly on the move
on your teeth, gums, lips and tongue.
Having bacteria in your mouth is a normal thing. While some of the
bacteria can be harmful, most are not and some are even helpful.
Certain types of bacteria, however, can attach themselves to hard
surfaces like the enamel that covers your teeth. If they're not removed, they
multiply and grow in number until a colony forms. More bacteria of different
types attach to the colony already growing on the tooth enamel. Proteins that
are present in your saliva (spit) also mix in and the bacteria colony becomes a
whitish film on the tooth. This film is called plaque, and it's what causes
A tooth is basically made up of two parts: the crown and the root.
what you see when you smile or open your mouth. It's the part that sits above
Therootis below the gumline. It makes up
about 2/3rds of the tooth's total length.
Four different tissues make up each tooth. The enamelis the durable, white covering. Enamel
protects the tooth from the wear and tear of chewing.
you know that the enamel on your teeth is the hardest substance in your body?
Dentinsupports the enamel
on your teeth. It's a yellow bone-like material that's softer than enamel and
carries some of the nerve fibres that tell you when something is going wrong
inside your tooth.
ThePulpis the centre of the tooth. It's a
soft tissue that contains blood and lymph vessels, and nerves. The pulp is how
the tooth receives nourishment and transmits signals to your brain.
Cementumis what covers
most of the root of the tooth. It helps to attach the tooth to the bones in
your jaw. A cushioning layer called thePeriodontal
Ligamentsits between the
cementum and the jawbone. It helps to connect the two.