The Crowning Glory

Media item: article

Date published: 8 September 2012

Subject: dental crowns

This page records the media item. The original article is the property of its publisher and is not reproduced here. The service page is Dental Crowns.

What a crown actually is

A crown is a laboratory-made or machine-milled cap that covers the whole visible part of a tooth. The tooth is reduced on all surfaces — typically by one to two millimetres, more on the biting surface — and the crown is cemented over it. What types of dental crowns are available? sets out the options.

That reduction is the entire trade. A crown protects what is left of a tooth by encircling and covering it. It does so by removing a substantial amount of it first.

When a crown is genuinely indicated

The evidence-based reasons:

1. The tooth has lost so much structure that a direct filling would leave thin, unsupported cusps. Every chewing cycle flexes an unsupported cusp, and eventually one splits. A vertical root fracture generally means losing the tooth. See Tooth Fillings and How long do dental fillings last?

2. After root canal treatment on a back tooth. This is the strongest indication. A root-filled molar or premolar has lost structure to decay, to the access cavity and often to a previous large restoration, and the evidence that cuspal coverage improves survival of root-filled posterior teeth is good. A root canal left under a temporary or a large direct filling is a treatment likely to fail. Root canal treatment itself is covered at Root Canal Therapy and Everything you need to know about root canal treatment.

3. A cracked tooth. Covering the cusps is what stops the crack propagating. Caught early, the tooth is saved; caught late, it is not. See Why does a cracked tooth hurt so much?, How will my cracked tooth be treated? and Chipped or Cracked Teeth.

4. A tooth already carrying a failed crown or a very large old restoration with recurrent decay — The stages of dental decay.

5. As an abutment for a conventional bridge, or on an implant. See Implant versus bridge for a single tooth replacement.

6. Severe wear, developmental defects, or discolouration that cannot be managed conservatively — What is dental erosion and how is it addressed?

When a crown is not the answer

Crowning a sound tooth for appearance is a large trade. It removes healthy structure permanently and commits the tooth to a lifetime of replacement.

Consider these first:

An onlay instead. An onlay covers only the cusps that need covering, leaving the rest of the tooth intact. The modern preference is for the most conservative restoration that will work, and that is very often an onlay rather than a full crown. Ask specifically whether an onlay would do. What is restorative dentistry?
A veneer, for a front tooth where only the facing needs changing — substantially less removal than a crown. What is the difference between porcelain crowns and veneers?
Composite bonding, which removes little or no tooth — What are the differences between dental bonding and veneers?
Orthodontics, if the problem is position rather than structure. Moving teeth removes none of them. See How can I change my smile naturally.
Nothing. A small chip or a stained old filling is not automatically a reason to crown — Do I have to get a chipped tooth fixed?

And on front teeth in particular: ‘instant orthodontics' — crowning crooked but healthy teeth to make them look straight — is the most over-sold procedure in dentistry. It is a real technique with legitimate uses, and it also means preparing several healthy teeth for a problem that orthodontics would solve without removing any. Turkey Teeth: the real risks of getting veneers overseas is what the extreme version looks like later.

Materials

All-ceramic — the usual choice now for visible teeth. Best appearance. Modern high-strength ceramics such as zirconia are also used on back teeth. Zirconia is very strong and very opaque, which is why a monolithic zirconia crown can look flat on a front tooth unless it is layered and characterised by a skilled ceramist. Milled options are covered at Same-Day CEREC Restorations.

Metal-ceramic (porcelain fused to metal) — the long-standing workhorse. Strong and predictable. Its weakness is appearance: the metal substructure blocks light, and a dark line can appear at the gum margin as the gum recedes over years.

Gold — by durability, one of the best materials ever used in dentistry. It is kind to the opposing teeth, seals well, and can be made thin, so it removes less tooth than a ceramic crown. It is used far less now purely because of how it looks.

The material choice matters less than two other things: how much tooth is removed, and who makes it. A crown is made by a dental technician or ceramist in a laboratory, or milled chairside. The ceramist is the single biggest determinant of whether a front crown looks like a tooth. Costs by material are at How much does a dental crown cost in Melbourne?

A note on titles: dental technicians and ceramists are not registered by the Dental Board of Australia — they are skilled tradespeople, not registered health practitioners, and they do not treat patients directly. Prosthodontics, by contrast, is one of the thirteen recognised dental specialties; a registered specialist prosthodontist is listed as such on the AHPRA register. See Specialist Prosthodontists and Dentists & Registered Specialists.

The questions to ask

‘Why a crown rather than an onlay?' — the most useful question in this area.
‘How much tooth is being removed, in millimetres?'
‘Does this tooth need root canal treatment first, or might it after?' Preparation stresses the pulp, and a proportion of heavily prepared teeth eventually need root canal treatment — which is an additional cost and belongs in the original conversation. See Endodontists.
‘Is a post needed?' Posts are placed in root-filled teeth to retain a core when there is very little tooth left. They do not strengthen a tooth — a common misconception — and they carry a risk of root fracture. Modern practice is to avoid them where enough tooth remains. Dental Myths Exposed covers a few more of these.
‘What is the total cost, including the core build-up and any post?' With ASDS item numbers, so you can compare and check your health fund — the price guide and Understanding Your Treatment.
‘How long should it last, and what happens when it fails?'
‘Where is it being made?' And if the plan is large, a second opinion is reasonable.

Living with a crown

Crowns do not decay. The tooth underneath them does.

That is the single most important aftercare fact. The margin where crown meets tooth is the vulnerable point, and decay under a crown is often painless and invisible until it is extensive.

So:

Clean the margin meticulously, including between the teeth — interdental brushes or floss, daily. See Is flossing really that important? and What is the ideal daily routine for oral hygiene?
Under a bridge, use superfloss or an interdental brush under the pontic — I'm looking to get a dental bridge to replace a tooth
Keep attending at your risk-based interval; decay under a crown is found on examination and radiographs, not by feel — how often should I go to the dentist?
If you grind, wear the splint. Ceramic fractures. See TMD & Teeth Grinding and What is bruxism and how is it managed?
If it feels high when you bite, go back and have it adjusted. Two minutes, and left alone it causes soreness and can crack something.
Some sensitivity for a few weeks afterwards is normal. Sensitivity that is worsening, waking you at night, or lingering after the stimulus is removed is not — go back. What to do if you suffer from sensitive teeth

Longevity: studies commonly report high survival at ten years, with figures falling over longer periods. Expect a crown placed today to need replacing at some point, and expect each replacement to take a little more tooth.

Common questions

I have been told a tooth is cracked, but the X-ray looks normal. How can they tell?

Because a crack usually does not show on a radiograph at all, and the European Society of Endodontology's 2024 position paper is blunt about it: in one study only 2% of cracked teeth with vital pulps had evidence of a crack on a radiograph. Three-dimensional imaging does not rescue the situation either — CBCT “is not predictable in detecting cracks”, although it may reveal subtle bone loss at the crest associated with one. So the diagnosis is made clinically: from where the pain is, what provokes it, transillumination, staining, and a bite test on individual cusps.

It also explains why a cracked tooth is so often missed for a long time. In a practice-based study of 2,858 teeth from 209 dentists in the USA, only 45% of cracked teeth were symptomatic at all — and where there were symptoms, the commonest were pain to cold (37%), pain on biting (16%) and spontaneous pain (11%). A tooth that hurts sharply when you release a bite, rather than when you clench, is the classic presentation worth mentioning by name at your appointment. See Why does a cracked tooth hurt so much?

For a cracked tooth, does it have to be a crown, or would a filling do?

This is a genuinely unresolved question and it should be presented that way. The ESE's 2024 position is that “there is no clear evidence on the most suitable restorative treatment approach” for a cracked tooth. What the same paper does report is a direction rather than a verdict: cracked teeth managed with direct bonded composite restorations “may be more likely to require root canal treatment and/or further repair of fractured restorations compared with cracked teeth managed with cuspal coverage restorations.” Across the studies it draws on, the incidence of endodontic intervention after restorative management runs between 7.7% and 20%.

So covering the cusps is the more protective option on current evidence, and it is not a certainty. The other half of the answer is that cuspal coverage does not have to mean a full crown. Guidance on restoring structurally compromised teeth states that restorations “should be designed to conserve as much sound tooth tissue as possible” and that “if cuspal coverage is required, onlay restorations [should be] used where appropriate.” Both the British Endodontic Society's Guide to Good Endodontic Practice (2022) and the ESE position statement recommend that each case be considered individually, with loss of proximal walls a strong indication for cuspal coverage. That is the substance behind the question above about asking for an onlay.

After a root canal on a back tooth, is a crown really necessary?

The evidence here is stronger than for most things in dentistry, and it is about extraction rather than appearance. “Studies have shown that cuspal coverage restorations significantly improved survival of the root-filled tooth”, and one recent study found that root-filled molars restored with a direct restoration were extracted significantly more often over a ten-year period than those restored with an indirect restoration.

The published risk factors are specific enough to check against your own tooth. Beyond how much structure is left, the factors that argue for cuspal coverage are tooth position, adjacent contacts and occlusal forces — and loss of a proximal contact, being the terminal tooth in the arch, or being a second molar have all been associated with an increased risk of failure of root-filled teeth. If your tooth has two or three of those, the case for covering it is much stronger than a general rule would suggest. Ask which of them applies to yours. See Endodontists.

How soon after the root canal should the crown go on?

Sooner than most people are told, and the figure is striking. In a retrospective study, posterior root-filled teeth that received a crown more than four months after the root canal treatment were extracted at three times the rate of those crowned within four months. The guidance is that where cuspal coverage is justified it “should be provided as soon as possible after completion of endodontic treatment, provided there are no signs and symptoms from the tooth” — and separately, “there is evidence of an increased failure rate of endodontic treatment with temporary restorations.”

The practical consequence is a budgeting one rather than a clinical one. The root canal and the crown are one treatment in two appointments, and the cost of both belongs in the quote you see at the start. A root canal completed and then left under a temporary while the crown is deferred for cost is the specific situation these figures describe. If affordability is the obstacle, say so before the root canal, not after — see Payment Plans and Price Guide.

How long does a crown last?

Nobody publishes a lifespan, and the sound figures we can point to are at five years, not the ten or twenty often quoted. A systematic review of single crowns (Sailer and colleagues, 2015) reported five-year survival of 94.7% for metal-ceramic, 96.6% for leucite- and lithium-disilicate-reinforced glass ceramic, and 92.1% for densely sintered zirconia. A separate prospective study (Passia and colleagues, 2013) reported five-year survival of 92.3% for gold crowns.

Two things follow. First, every one of those materials sits within about four percentage points of the others at five years, which is the evidence behind this page's point that the material matters less than how much tooth is removed and who makes the crown. Second, we can find no independent source that gives a crown survival figure at ten or twenty years, so if you are quoted one, ask where it comes from. What is safe to plan on is the direction rather than a date: a crown is a restoration that will need replacing at some point, and each replacement takes a little more tooth.

Is this page the original media item?

No. This is an archive and context page. Third-party recordings, articles and broadcasts remain the property of their publishers and are not reproduced here unless the page explicitly says otherwise.

Should this archive page be treated as current clinical advice?

No. This article was published in 2012 and the evidence has moved since — most of the figures quoted in the questions above were published after it appeared, including the 2024 position paper on cracked teeth. Media items preserve the context in which they appeared, while clinical guidance, fees, practitioners and services change. Use the current service pages linked here and obtain an individual assessment from an appropriately registered practitioner.

Practical details

Smile Solutions, Level 1, 220 Collins Street, Manchester Unity Building, Melbourne VIC 3000. Phone 13 13 96, or theteam@smilesolutions.com.au. Monday–Friday 8.00am–6.00pm, Saturday 8.30am–1.30pm, Sunday by appointment. Directions are on Location; enquiries go through Contact Us.

Every practitioner's registration and any specialist entry can be verified free on the AHPRA public register at ahpra.gov.au.

This page records a published article and its date, with general information. It is not a diagnosis, a treatment plan or a promise of any particular outcome. Crowns are irreversible, carry risks including sensitivity and pulp death, and survival varies widely with the individual case. Survival and incidence figures quoted above are drawn from published research on other populations, apply at the time points stated, and are not predictions about any individual tooth. Third-party published content is not reproduced.

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