Crowns, Onlays and Bridges
If you have badly damaged or missing teeth, your dentist may discuss the option of crowns, onlays or bridges to help restore your smile.
Crowns and onlays are often used where single teeth are too damaged for standard filling methods, particularly if a lot of the tooth is missing. This could be due to an accident for example or if the tooth has already been filled several times in the past. Crowns can also be used over implants.
A crown or onlay is then fabricated to either completely or partly replace the structure of this badly damaged tooth, preventing it from getting worse and giving it the appearance of being normal and healthy. Crowns usually involve removing more tooth structure than onlays.
A dental bridge is a fixed replacement for one or more missing teeth. As the name suggests, it bridges a gap, using one or more teeth as anchors to keep the bridge in place.
Bridges come in different designs. One type of bridge can be adhesively bonded to a tooth next to the gap and usually requires minimal tooth adjustment. Another type can involve two crowns joined together by a middle section that fills the gap: The teeth either side of the gap need to be shaped for the crowns to be fitted, so if the teeth are not particularly strong themselves, this type of bridge may not be suitable for you. Your dentist can advise you of the different types of bridges.
With implants now becoming more affordable and widely available, bridges that involve lots of drilling are becoming less common.
Bridges can also be placed on implants.
The preparation for bridges and crowns is almost identical. They will usually only need two appointments after an assessment or examination.
Assessment: Your dentist will first assess what work is needed, taking x-rays to properly examine the area.
Preparation: Your teeth will be shaped under local anaesthetic to prepare them to accept the bridge. Next, impressions and colour checks are taken and everything is sent to a lab to be constructed. You may have something temporary fitted to protect your teeth while you wait.
Fitting: Your crown or bridge should arrive in around two to three weeks. Your dentist will check the fit and then fix it in place with dental cement. Sometimes it will be temporarily fixed for a short time to ensure it fits properly before it’s permanently secured.
They can be fabricated in a variety of materials, e.g. tooth-coloured options such as porcelain or modified ceramics (either as one layer or as an outer layer surrounding a strong inner core). Tooth-coloured options are typically made to match to the colour of your natural teeth.
They can also be made using metals, e.g. gold or silver-coloured alloys, which can be thin as well as strong, and usually require less tooth to be drilled away.
Your dentist can advise you of the different types of crowns/onlays that are available.