Taking Care of Cavities

When you go for a check-up, one of the things your dentist looks for is tooth decay, also known as a cavity. If you have a cavity and it needs a filling, there are different kinds of fillings to do the job.

The Choices you have

Your dentist cares about your oral health. If you have any questions or concerns about the kind of fillings that are used in your mouth, talk to your dentist.

Each kind of filling has pros and cons. What you choose depends on your needs. When something foreign is put into your body, there is always the chance of side effects, such as an allergy. For every filling material, there are a few people who are allergic to it.
Before you get a filling, you should tell your dentist about changes to your health since your last visit:

Are you taking medicine?
Do you have allergies?
Are you pregnant?

Your dentist can suggest the kind of filling that is best for you. But the final choice is yours.

How a Cavity forms

A cavity is a very small hole that forms on the surface of a tooth. Cavities are caused when two things mix together:

• sugars in the food we eat, AND
• germs (or bacteria) in our mouths.

When these things meet inside your mouth, they produce a mild acid. This acid can eat away at the hard, outer layer of your teeth (called enamel).

Cavities are more common during childhood, but adults can get them too. Adults tend to get 2 kinds of cavities:

1 - Cavities that form around a filling, or "recurrent" cavities. Fillings are not as smooth as natural teeth. Tiny bits of food and germs (bacteria) can get caught at the edge of a filling. This can cause a cavity to form again on the tooth around the filling. Also, if a filling breaks, the part of the tooth that is no longer covered is more likely to get a cavity.

2 - Cavities that form on the roots of the teeth, or "root" cavities. Years of brushing your teeth too hard can make your gums recede, or pull away from your teeth.

Getting older can also make your gums recede. When your gums pull away from your teeth, the roots of the teeth are out in the open. Roots do not have a hard, outer layer (enamel) to protect them, so they are more likely to get cavities.


How Fillings are Done

To fill a cavity, your dentist may first give you "freezing" (or local anesthetic) so you do not feel any pain. Your dentist takes out all traces of decay and shapes the hole and fills it with the kind of filling you need and want.

There are 2 main ways fillings are done:

1 - Direct Filling
These fillings go right into the cavity, after your dentist has cleaned out the decay. Amalgam (or silver) fillings and plastic (or white) fillings are examples of direct fillings. They harden quickly. Most of the time, you will be able to have a direct filling put in place in 1 appointment.

2 - Indirect Filling
Examples of this type of filling are crowns (or caps) and inlays. They are made in a lab to fit your tooth alone. Your dentist cements the filling in place. Most indirect fillings takes 2 or more appointments to complete.

Kinds of Fillings:

Metal Fillings

Dental Amalgam Filling

These are sometimes called "silver" fillings. They are the most common kind of filling used in Canada today. Because these fillings are silver in colour, they are used to fill back teeth. They are a mix of metals such as mercury, silver, copper and tin.

Cast Gold Fillings

These are based on a model (or cast) of your tooth. Cast gold fillings are a mixture of gold with other metals such as silver and copper. These other metals make gold filling more durable.

Tooth Coloured Fillings

Composite Fillings

These are also called plastic or white fillings. Getting this kind of filling depends on where the tooth is in your mouth. We bite down hard on our back teeth (molar), so a plastic filling may not be a good choice here. Talk to your dentist about your other choices.

Glass Ionomer Materials

These are only used in teeth where you do NOT bite down hard. There have not been many studies about how long this kind of filling lasts. Newer forms of the filling may be stronger and may last longer.

Porcelain Materials

These are the most common kind of dental ceramic used by dentists. They are hard and brittle. Porcelain and metal can be combined to make a strong, tooth-coloured crown. The crown is based on a model of your tooth. It is made in a dental lab in much the same way as a cast gold filling or crown is made. Unless you have a bad tooth grinding habit or some other problem, a combination of porcelain and metal can be used anywhere in the mouth.