Fillings are used to preserve teeth that have been partially damaged by decay. Tooth decay occurs over time due to bacteria in the mouth. When we eat and drink, bacteria in the mouth mixes with sugar in our foods to form a mild acid that damages the teeth and causes cavities.
How to Tell if you Need a Filling
The only way to know for sure whether you have a cavity (and need a filling) is by having your family dentist perform an oral exam. Symptoms of cavities can include tooth sensitivity, pain when chewing, and brown, white, or black discolouration on the teeth. Your dentist will check for soft spots on the teeth as well as discolouration and other signs of decay. Your dentist may also recommend x-rays of the mouth to confirm the diagnosis and recommended treatment. If the decay is severe, your dentist may recommend extraction or a root canal.
Dental Filling Procedure
When you book an appointment to get a filling, your dentist will follow several steps to remove the tooth decay, clean the area, and re-fill the tooth to seal the spaces where bacteria can enter. The procedure includes the following steps:
- Administration of local anaesthetic (freezing) to numb the area to be treated.
- Removal of tooth decay using special tools, including small dental drills. In some cases, your dentist will also shape the area prior to filling it.
- Etching and/or resin application: For a bonded filling your dentist will apply an acid gel to etch the area to be filled. For certain types of fillings your dentist will fill the tooth with layers of resin that are hardened with a special light.
- Polishing: The completed filling will be polished and your dentist will double check the bite alignment for fillings that are on the bite surface.
Types of Dental Fillings
Materials used for fillings include amalgam (mixture of mercury, silver, copper, tin and sometimes zinc), gold, composite resin, glass ionomer, and porcelain.
- Dental amalgam, or “silver” fillings are commonly used to fill back teeth. They are low cost and long lasting, but the colour does not look natural. In addition, small amounts of mercury can be released from amalgam fillings, which has caused health concerns in the past, but the tiny amounts of mercury are generally not harmful.
- Gold fillings are made using a cast of your cleaned tooth, so it takes more than one appointment to get a gold filling fitted, made, and placed. Gold is stronger than amalgam but is also more expensive and does not have a natural look.
- Composite (white) fillings are done in a single appointment using layers of resin. Composite fillings are a good choice for visible areas since they look like your natural teeth, but they are not as strong as metal fillings so they may not last as long, especially on the back molars. Composite fillings break and crack more easily than metal, so the risk for recurrent decay is higher. Composite fillings are more expensive than amalgam but less expensive than gold.
- Glass ionomer fillings are not very common. They have a natural look like the composite fillings but do not need to be applied in layers. Glass ionomer fillings contain fluoride to prevent further decay, but are not very strong compared to other materials. These fillings are more expensive than amalgam but less expensive than gold.
- Porcelain materials are more commonly used for crowns. Like gold, porcelain fillings are made in a dental lab and therefore require more than one appointment. Porcelain and metal can be combined to make a stronger material, but these fillings are still not as strong as other materials and are also one of the more expensive options.
To prevent cavities (and avoid the need for fillings), remember that the Canadian Dental Association (CDA) recommends brushing the teeth and tongue twice a day with soft manual or electronic toothbrush. For patients that are old enough to use fluoride without swallowing, a fluoridate toothpaste is most effective. Regular flossing is also important, since you can miss up to a third of the tooth’s surface by skipping the floss. Your dentist may also recommend sealants for deep grooves on molars to help prevent bacteria from getting into the crevices. Speak to your dentist if you have any questions about oral care, cavities, or fillings.