The truth about crowns

Getting a crown might be cause for celebration if you’re a member of the royal family, but for the rest of us it’s simply an effective solution to a dental problem. A dental crown (also known as a ‘cap’) is a hollow artificial restoration that fits over the remaining part of a tooth to restore its shape, appearance and function.

Sometimes crowns act as a filling, covering a broken or decayed tooth when there is too much tooth missing to hold a conventional filling. Sometimes they are used to support a weak tooth or protect it from breaking.

Crowns may also be involved in holding a dental bridge in place, covering a dental implant or covering a tooth after a root canal. And when it comes to appearances, a crown can cover stained, discoloured or badly shaped teeth (although veneers may be an alternative in these circumstances).

What are they made of?

Most crowns are made of either porcelain (often used for front teeth as it looks very natural) or a combination of porcelain and metal, which is much stronger than porcelain alone. Metals including gold, palladium, nickel or chromium are also used.

Another crown alternative is all-resin, which is less expensive but less durable. Less commonly, a gold-alloy (gold mixed with other metals) or glass will be chosen by your dentist.

Dr Akshay Sidana from Clearly Dental Dapto, says usually “your crown is sent to a ceramist or lab technician to make”.

“It comes back looking and feeling like a lifelike tooth, which is part of the artistry of dentistry – and that is one of the reasons they are so technically involved and are at that higher price point. Patients want a crown that looks and feels like a tooth and will go the distance [for it],” he says.

The crown procedure

Having a crown fitted involves at least two appointments. In the first visit, the dentist will give you an anaesthetic if necessary, then prepare the tooth for restoration by removing a layer of the outer surface (the finished crown will be the same thickness as this layer). The dentist will take an impression of this tooth and those next to it – this mould will be used by a technician to create your crown. A temporary crown may be placed over this tooth to protect it until the final crown is ready.

“You’ll be given a numbing injection when you have a crown done, so for the duration of the appointment there shouldn’t be any reason why you would feel pain,” says Dr Sidana. “After the appointment, some patients can feel that their jaw is a little sore from having to stay open for a long period of time.”

At the next appointment, usually one or two weeks later, your dentist will remove the temporary crown and apply the final one. If it fits well and is a good match in terms of colour, shape and bite, cement or adhesive will be used to seal it into place.

“In the time between the two appointments, your tooth can feel a little bit sensitive to cold, but that usually settles after a few days. We usually tell our patients to use some sensitive toothpaste during that time,” says Dr Sidana.

What happens next?

Initially your crown may feel different to your other teeth but you will quickly get used to it, and over time you won’t notice it at all. If, however, your bite doesn’t feel comfortable after a few days, see your dentist – they will be able to adjust it for you.

In terms of ongoing maintenance, a crown can’t decay like regular teeth, but the edge of the tooth it sits on can, so you’ll need to brush and floss your teeth as usual to reduce the risk of decay.

“People think, ‘I’ve got this crown now, it’s not a real tooth, I don’t need to brush it as well, I don’t need to floss it as well’, but you certainly do,” says Dr Sidana. “That tooth is still susceptible to many issues.

“It’s also important to make sure that your dentist is reviewing that tooth, whether that be with six-monthly check-ups and giving it a good clean to remove any plaque or tartar build-up around the gums, and also with X-rays routinely.”

Remember your crown may not be as strong as your natural teeth, so avoid putting it under strain by biting on hard objects or by opening or cutting things (which is good advice for your natural teeth, too).

A crown should last around 10 years if you look after it well, but can break or fall off if the cement doesn’t hold, or if the tooth underneath decays.

“When we’re doing restorations we obviously want them to last as long as possible but I think it’s important for patients to go in with a realistic understanding that things do need maintenance, and over time they may need to be replaced just because of the harshness of the environment of the mouth,” says Dr Sidana.

Are crowns expensive?

Because this treatment involves two appointments with a dentist and a technician making the crown from a mould, it is more expensive than simpler dental treatments.

“I think it’s important to recognise that a crown appointment is very different to a filling, and that is why there is a jump in the price point between a filling and a crown,” says Dr Sidana.

“Crowns have an average lifespan much greater than a filling. And there is also a lot more involved in crown appointments than in your standard filling appointment.”

What about same-day crowns?

Some dentists offer same-day crowns, where instead of a physical mould being taken of the tooth, a specific camera is used to take an optical impression, the crown is then designed, and a milling unit creates the crown while you wait.

“One benefit is that it’s all done and dusted on the same day and you don’t need to wear a temporary crown between the appointments,” says Dr Sidana. “However, in highly aesthetic cases, the two-visit process and use of a skilled ceramist may result in a more natural-looking crown.”

Make sure you discuss the advantages and disadvantages with your dentist to decide whether same-day crowns are right for you.

Sources

• www.mouthhealthy.org/en/az-topics/c/crowns
• www.cda-adc.ca/en/oral_health/procedures/crowns
• www.healthdirect.gov.au/dental-crown-procedure
• www.dentalhealth.org/crowns
• my.clevelandclinic.org/health/treatments/10923-dental-crowns
• www.choice.com.au/health-and-body/dentists-and-dental-care/dental-treatment/articles/dental-fees