Crowns and Bridges

What is a Crown

A dental crown is a tooth-shaped “cap” that is placed over a tooth — to cover the tooth to restore its shape and size, strength, and improve its appearance.

The crowns, when cemented into place, fully encase the entire visible portion of a tooth that lies at and above the gum line.

Why is a crown needed?

• To protect a weak tooth (for instance, from decay) from breaking or to hold together parts of a cracked tooth
• To restore an already broken tooth or a tooth that has been severely worn down
• To cover and support a tooth with a large filling when there isn’t a lot of tooth left
• To hold a dental bridge in place
• To cover misshapened or severely discoloured teeth
• To cover a dental implant
• To make a cosmetic modification
• To strengthen a root filled tooth, all root filled teeth should have a crown or at least onlay covering them

The Process

It usually takes 2 appointments for a crown to be made following the initial consultation. An x ray will usually be taken prior to the treatment starting.

The tooth is ‘numbed’ using local anaesthetic and then prepared by reducing the tooth by 2-3 mm following the original contours of the tooth, not a small peg shape as historically prepared teeth were.

Impressions or scans are done of the tooth and the opposite arch to make sure both the fit and bite of the crown is perfect. A shade will be taken to ensure a great match to the rest of the teeth.

A temporary crown is made at this appointment which will be in place for 1 – 2 weeks. This is designed to be removed easily so it is important to be careful to avoid hard, sticky foods or flossing around the temporary for this interim patch.

The second appointment will be much shorter and may involve numbing. The temporary will be lifted off and the new permanent crown tried in to make sure it fits and looks perfect. When both the dentist and patient are happy the permanent crown is cemented in place with an incredibly strong cement. It is highly unlikely it will ever de bond.

New Materials

With scanning and 3D printing technology crowns are now made of scientifically advanced materials. The 2 main materials we use at Gwynne Dental are Zirconia and eMax.

E Max Crowns

These are special type of crowns made from lithium disilicate material. These crowns are made from a single block of this material which makes it a high strength crown free from imperfections. Lithium disilicate is known for its superior strength and appealing aesthetics as a restorative crown material. E-max crowns are slightly translucent and hence come closest to matching your teeth colour. This property has made it a great choice for crown restoration in front teeth.

Zirconia

Zirconia is the ceramic form of zirconium and is closely related to titanium. It is tooth coloured, strong yet a lightweight ceramic with fantastic bio-compatibility. It is stronger than emax but not quite as aesthetic. We use it in posterior teeth where strength is required.

Risks

The only risk of having a crown placed on a ‘live’ tooth is that the tooth becomes non vital. This can cause discomfort and require the tooth to be root filled. It is best not to root fill (root canal treatment) the tooth first unless it is necessary as a ‘live’ tooth is stronger.

Bridges

Bridges are made from the same materials and act to close a missing tooth gap. They do this by crowning adjacent teeth and attaching the ‘false’ pontic tooth to the crowns which ultimately support it. This takes 2 appointments as per crowning a tooth and has a very similar process.