Oral Health Resources | 23 August, 2019

Fillings - Everything You Need to Know

So, you’ve been told you need a filling… Here’s everything you need to know:

What, why and how

A filling is a way to restore a damaged tooth back to its normal function and shape. The most common use of tooth fillings is to fill a cavity in the tooth. But tooth fillings also can be used to repair damage to teeth caused by teeth grinding (bruxism) or to replace part of a broken tooth.

You should expect to be at your dentist’s office for around an hour. This gives him or her enough time to take x-rays if needed, talk to you about the procedure and complete the dental work.

Before filling cavities, your dentist will numb your teeth, gums and surrounding skin to avoid and lessen discomfort during the procedure.

Next, he or she will drill out the decay in the tooth and replace it with a filling. This process only takes a few minutes.

Once you’re done, your mouth will probably remain numb for a few more hours. There aren’t any significant risks associated with filling cavities, but be sure to keep your dentist’s contact information on hand in case you have any questions or complications.


Often there are no symptoms of tooth decay (technically known as caries).  However symptoms that you may need a filling can include; (but are not limited to) sensitivity of the tooth to pressure or sugary foods, toothache or pain (can be a sharp or throbbing pain), a hole in the tooth that you can see or feel, or floss that keeps tearing in a particular spot.

Your dentist will always check if you need fillings as part of a full examination which will include x-rays if necessary.

It is important that you regularly see a dentist because not all decay and problems give rise to any symptoms or pain. In fact, most start silently in the early stages and if picked up early can mean a simple, cost effective and less invasive treatment instead of a more expensive and complex procedure if left untreated.

Prevention is key so ask yourself when you last had a full dental exam and x-ray and call your local practice for an appointment if it has been longer than 12 months.

Choosing your dental filling

When new cavities need attention, or old fillings need replacement, you have several choices for the type of filling to be used.

Composite or white fillings

Composite fillings are by far the most popular fillings in New Zealand because of their excellent natural appearance and strength. Their durability is now comparable to amalgam fillings. A composite filling is selected to match the colour of your teeth as closely as possible. They are almost impossible to detect and are an excellent replacement for stained, chipped or leaking fillings.


  • Cosmetic appearance
  • May bond a weak tooth together, reducing the risk of fracture in an extensively filled tooth
  • Can be fitted into very small holes, so less drilling is needed in preparation for the filling


  • Composite fillings take longer to place than amalgam fillings
  • Higher cost compared with amalgam fillings
  • Not a good choice for patients with ha lot of cavities
  • Increased sensitivity in some cases

Gold fillings

The advantage of gold fillings is their strength and durability, although they are more expensive than other filling types.

Glass ionomer cement fillings

Glass ionomer is a tooth-coloured material that was originally used as a dental cement for gluing crowns onto teeth. Today, glass ionomer may be used in a variety of ways, including as a filling material. It is the least costly material to apply, however, in many cases it has the shortest life due to its low wear-resistance.

It is typically used as a temporary filling, or as a foundation underneath fillings made of composite. In the future, technological advancements may see this material becoming just as durable as the other materials.

Porcelain inlays or onlays

Porcelain is a ceramic material that is matched to the tooth colour to provide a cosmetic result. It is a material designed for use on back teeth, and is glued into the tooth cavity with a special, powerful glue that increases the strength of the bond. The porcelain filling is extremely strong and wear resistant. It can last indefinitely, provided you do not get a new cavity underneath it, or abuse your teeth.


  • Very strong
  • A cosmetic tooth-coloured alternative
  • Long service life
  • Fillings generally weaken teeth, but because inlays are bonded to the tooth, they can offset this weakening to some degree


  • Inlays are the most expensive of the filling materials.

Gold inlays or onlays

The advantages of these restorations are similar to porcelain inlays or onlays with their excellent strength and durability. They are more expensive than other filling types.

Dental amalgam

Dental amalgam has been around for more than 150 years. It is a cost-effective way of filling teeth and a small to moderate-sized amalgam filling can last many years before it wears out and requires replacement. Dental amalgam is made up of silver, tin, copper and mercury.

The American, Australian and New Zealand Dental Associations report that amalgam fillings are safe for patients. A large number of our Lumino practices do not use amalgam fillings as there are many other alternative materials to use.


  • Strong, long lasting, proven material.
  • Low cost.
  • Material seals itself into the preparation, inhibiting recurrent decay.


  • It is not tooth-coloured
  • It does not bind the tooth together
  • More tooth structure may have to be removed to get the amalgam to stay in the tooth
  • Contains mercury in trace amounts