A crown is one of the more expensive things a dentist can suggest, so it is fair enough that people want to know whether they actually need one. My answer, more often than patients expect, is not yet.
That is not modesty. Prosthodontics and complex bite problems are my main clinical interest, and crowns are the work I most enjoy doing. But the principle I run this practice on is that we recommend the simplest solution that will achieve what the patient actually wants from their teeth. If a tooth will do fine with a filling for another five years, crowning it today buys nothing and spends tooth structure I can never give back.
So: what a crown does that a filling can’t, what I am looking at when I decide, and the situations where I tell people to leave the tooth alone.
What a crown does that a filling can’t
A filling fills a hole. That sounds obvious, but it has a consequence: a filling relies on the tooth walls around it for strength. It does not add strength of its own. Composite bonds well and modern materials are good, but a filling sits inside the tooth, and the walls still have to hold themselves up.
A crown does the opposite. It wraps the outside of the tooth and holds the cusps together, so when you bite down the force is contained rather than splitting the tooth apart.
That distinction matters because of how back teeth actually break. Molars have cusps either side of a valley. When you bite on something hard, those cusps flex apart very slightly. A tooth with all its walls intact resists that easily. A tooth hollowed out by decay and refilled two or three times has thin walls and a wide filling sitting in the middle of it like a wedge, and every bite drives that wedge a fraction further. Eventually a cusp shears off, usually below the gum on one side, and the repair options get worse.
That is the whole argument for a crown. Not that the hole is big, but that the tooth can no longer contain its own biting forces.
What I am actually looking at
When I assess a tooth for a crown, the size of the existing filling is almost a side issue. There are four things I want to know.
How much sound tooth is left, and where. Specifically the thickness of the remaining walls and whether the marginal ridges, the raised rims between your teeth, are still intact. A tooth can have a large-looking filling on the X-ray and still have thick, sound walls. Another can have a modest filling that has undermined a cusp completely.
Whether there is a crack, and what sort. Craze lines on the enamel surface are extremely common and mostly harmless. A crack running through the floor of a filling into dentine is a different matter, and one I can usually see with an intraoral camera and show you on the screen. If you have ever had a sharp jolt when you release a bite rather than when you clamp down, that is the classic sign and it is worth a proper look.
Whether the tooth is root-filled. A root-treated back tooth has had its roof opened to reach the canals, which is exactly the structure that stops the cusps flexing. Cuspal coverage on root-filled molars and premolars is standard care for that reason, and it is the one situation where I push for a crown fairly firmly. Front teeth after root canal treatment are often a different story and can sometimes be restored more conservatively.
Your bite. If you grind, the load on that tooth was never normal chewing load. Fixing the tooth without addressing the force that broke it means we meet again.
When I say no, or not yet
These are real conversations from most weeks in this chair.
A large old amalgam that is intact, sealed, with no crack and no symptoms. I photograph it, take a bitewing, and we watch it. Amalgams that have been quietly doing their job for twenty years sometimes keep doing it for another ten. Replacing a sound filling is not free: every re-preparation removes more tooth. If you want it changed for other reasons, that is a separate conversation and a legitimate one, but it is not the same as needing a crown.
Craze lines on a front tooth. Very common, especially past forty. They are surface enamel lines and they do not mean the tooth is failing.
A front tooth someone dislikes the colour or shape of. That does not need a crown. Take-home whitening or composite bonding will often do it, and both leave the tooth intact. I have talked nearly every patient who came in asking for in-chair whitening into the take-home version instead, because the result is more controllable and easier on sensitivity.
Gums that still bleed. We do not build restorative work on unstable gums. If there is active gum disease we treat that first and reassess, for two reasons. The obvious one is that a crown margin sits at the gum line, and if the gum recedes later that margin ends up exposed. The less obvious one is technical: bleeding at the margin makes it impossible to record the shape accurately or to bond in a dry field, so what you get is simply a worse crown. Treating perio first is not a delaying tactic, it is what makes the restoration work.
A grinder without a splint. If clenching cracked the tooth, it will happily crack the crown too, or the tooth underneath it. We can make the crown, but I want an occlusal splint in the plan alongside it, not instead of it.
A tooth with a poor long-term outlook. Deep bone loss, a vertical root fracture, or too little sound tooth left below the gum to grip onto, and a crown becomes money spent on a tooth that is leaving anyway. I would rather say so plainly and talk through the alternatives than crown it and have that conversation in two years.
The option nobody offers you: the onlay
This is where a lot of unnecessary crown work comes from. The choice gets presented as filling or crown, when for a great many teeth the right answer sits between the two.
An onlay covers only the parts of the tooth that need covering. If one cusp is undermined and the rest of the tooth is sound, we can cap that cusp and bond the restoration onto the structure that is still good, rather than grinding the whole tooth down to a stump for a full crown. We make inlays and onlays here in the same materials as our crowns: e.max, zirconia, gold and porcelain-fused-to-metal. Bonded e.max onlays in particular are a genuinely conservative way to protect a cracked or heavily filled molar.
Onlays get offered less often than they should because they are more technique-sensitive. They rely almost entirely on the quality of the bond, which means they rely on the field being dry. Under rubber dam, with the prepared surface air-abraded immediately before bonding, that is achievable and repeatable. Without that isolation it is a gamble, and a full crown that grips mechanically is the safer bet for the dentist. Which is fair enough, except that the patient pays for it in tooth structure.
What it costs, and what to ask
Crowns are itemised nationally. A full veneered indirect crown is Australian Dental Association item 615. For national context, the ADA’s 2022 fee survey, reported by CHOICE, put the average charge for item 615 at $1,678, with most fees falling between $1,250 and $2,100. That is a national average, not our fee. You get a written treatment plan with the actual figures on it before anything starts. We have HICAPS on site so any health fund rebate comes off on the day, and we are an HCF More For Teeth preferred provider.
Four questions worth asking any dentist who recommends a crown:
- What happens if I wait six months? There is a real answer to this and it differs tooth by tooth. “It might get worse” is not an answer.
- Can I see it? We have intraoral cameras and I will put the photo up on the screen. Looking at your own crack changes the conversation.
- Is an onlay possible here, and if not, why not? If the answer is a shrug, ask someone else.
- What is the plan for whatever caused this? Grinding, dry mouth, diet, gum disease. Fixing the tooth without fixing the cause is a subscription, not a treatment.
If you want a second opinion
Bring your X-rays, or we will take our own. A first appointment here runs a full hour, and the first ten to thirty minutes is conversation before any instrument goes near you: what you want from your teeth, what has happened to you in the past, what you are trying to avoid. That is where a treatment plan actually gets decided, and it is the part that most often ends with fewer crowns than the patient walked in expecting.
To have a tooth looked at properly, call us on (03) 8838 8820 or book online. We are at 129A Canterbury Road, Blackburn, with on-site parking and Saturday morning appointments if weekdays are difficult. Consultations are available in Mandarin, Cantonese, Teochew and Shanghainese as well as English.
Related reading: what actually happens when you get a crown, appointment by appointment · how long crowns last and what decides it · why teeth break and chip in the first place · our crowns and bridges page.