woman getting her fillings checked by dentist with mirror and scaler

What is the difference between Fillings, Inlays and Onlays?

Dental fillings, inlays and onlays are dental restorations used to restore your natural tooth structure. These types of restorations are generally used when your tooth has been affected by tooth decay (cavities). Some differences between each type of treatment include:

  • The area of the tooth each treatment fills or covers
  • Size of the cavity being removed
  • Dental material used
  • Required procedure time

Furthermore, you may require one of these restorations if you start to develop:

  • A tooth ache
  • A hole within your tooth
  • Teeth sensitivity

What is a filling?

A dental filling is a common treatment used to treat decay within your tooth. If decay spreads within your tooth you may require your dentist to remove the affected area and fill it with strong, dental material. The aim of this is to restore the strength and functionality of your tooth. Furthermore, your dentist may fill your cavity with filling material such as composite resin or amalgam.

A composite resin filling is often referred to as a white filling. Composite resin is a dental material that matches the natural colour of your teeth far better than an amalgam or silver filling. If you are looking to enhance your aesthetic look, a composite filling could be an option for you as amalgam is a metal-based material.

Composite filling replacing decay within tooth

At The White Bite, we do not use amalgam to restore your decayed tooth. However, we do offer to remove old amalgam fillings and replace them with white (composite) fillings. This helps your old filling to resemble the colour of your surrounding natural teeth.

Furthermore, there is the risk of an amalgam filling releasing low amounts of mercury vapor. Over time, this may lead to mercury being inhaled or absorbed into your lungs. The mercury stems from its metal components used to create the material such as silver, copper or tin.

What is an inlay?

An inlay is used to fill an area of your tooth that is bigger than a general dental filling. It usually covers the area between the cusps (bumps) on your teeth. For this reason, they are shaped to fit perfectly within the area of your teeth that has been removed by your dentist. The aim of this is to prevent food and other bacteria entering underneath your filling and creating further decay.

Silver filling inlay on tooth

For the amalgam inlay above, your dentist may replace this type of material with a solid dental material such as gold or ceramic (porcelain).

The use of a ceramic filling may help your dentist restore your tooth to match the surrounding teeth. In addition, inlays may be stronger than a composite filling as the filling is larger and needs to be durable to prevent further issues.

Material like porcelain are also used for dental treatments such as veneers.

What is an onlay?

Onlays are often referred to as partial crowns as they may cover one or more cusp of your tooth. For example, if your tooth is showing signs of decay within a section of the middle and side of your tooth, you may be required to have an onlay. As seen below, an amalgam filling has been replace with a composite onlay to restore the tooth.

Composite inlay replacing old amalgam filling

Usually, an onlay may be required to cover more area of your tooth than an inlay and filling but less area than a dental crown. A crown is used to cover your whole tooth to restore its functionality. Hence, why an onlay may be referred to as a partial crown.

For this treatment, your dentist may use materials such as:

  • Porcelain
  • Composite resin
  • Or even gold

These materials are placed once the cavity within your tooth is removed by your dentist. The materials are bonded to your teeth so that your filling withstands pressure from movements such as grinding your teeth or eating.

The difference between fillings, inlays and onlays

Generally, an onlay is used to cover a cusp (bump) of your tooth and an inlay is used to fill larger holes or areas between the cusps. As they are made from materials such as porcelain, they may not be at risk of shrinking due to their ceramic nature unlike a composite filling.

Furthermore, these two treatments may require you to attend to two visits with your dentist. During your first visit, you will have your cavity removed and an impression of your tooth will be taken. Following this, your impression will be sent to an external lab where your inlay or onlay with be created. Once your restoration has been made, your dentist will bond your inlay or onlay to your tooth at your next appointment. In some cases, your inlay or onlay may last for up to 20 years.

On the other hand, filings may be completed within one visit as they are for smaller, basic cavity issues. However, in some cases you may require an impression to be taken and sent to an external lab so they can create your custom filling. Therefore, you may require a second dental appointment.

In addition, your filling may need to be replaced over time due to the nature of the composite material. This could be caused by either the filling shrinking or being worn out over time from eating. With proper oral care, your composite fillings may last between 5 to 15 years.

Fillings on the Gold Coast

If you are looking for dental restoration options such as fillings, inlays or onlays to restore your tooth on the Gold Coast, contact our friendly staff today. Alternatively, you can fill out our free online consultation form.