Crown, Onlay or Filling?
How we decide between a filling, an onlay and a crown, what each one costs, how long they last and what happens at the appointment.
Do I Need a Crown, an Onlay or a Filling?
It depends how much healthy tooth is left. A small cavity needs a filling. Damage to the biting surface with strong walls usually suits an onlay, which keeps more of your own tooth than a crown. A tooth that has lost most of its structure, or has been root filled, usually needs a crown to stop it splitting. At St Vincent Smile in Finnieston, Glasgow, tooth-coloured fillings start from £105, a ceramic onlay is £750 and ceramic crowns start from £675, all confirmed in a written plan before treatment starts.
How Do We Decide?
Every tooth we restore starts with the same two questions: how much healthy tooth is left, and how much force will it take when you bite? A filling is the least invasive option, and we use it whenever we can. When a cavity or an old filling has taken up much of the tooth, a filling alone can leave the remaining walls thin and prone to cracking. That's when we move to an onlay or a crown, which cover and protect the tooth rather than just filling the hole.
| If the tooth has… | Usually best |
|---|---|
| A small cavity | A filling |
| Damage to the biting surface, but strong walls | An onlay |
| Lost much of its structure, or been root filled | A crown |
We'll show you on your X-ray and your scan why we're suggesting one over another. We always keep as much of your natural tooth as we can.
Fillings
A filling repairs a cavity or a small chip. We use tooth-coloured composite, matched to your teeth and bonded to the tooth, so it helps support what's left. It's done in one visit under local anaesthetic: the decay is removed, the tooth is cleaned, and the composite is built up in layers and set hard with a light. You can eat as soon as the numbness wears off.
Fillings start from £105 on a front tooth and £118 on a back tooth, and the fee rises with the number of surfaces the filling covers. A filling is the right choice for small to medium cavities. Where a filling would take up most of the biting surface, or a large old filling keeps breaking, we'd usually suggest an onlay instead, because a very large filling leaves the tooth weak.
A Broken or Filled Tooth?
Book an examination and we'll explain your options.
Onlays
An onlay is a piece of ceramic made outside the mouth to fit the tooth exactly, then bonded on. It covers and protects the biting surface, replacing one or more of the cusps, while leaving the healthy walls of the tooth untouched. That's its advantage over a crown: it protects the tooth from splitting without shaping away sound enamel all the way round.
Onlays suit back teeth with a large cavity or a failing filling, teeth that have cracked but still have strong walls, and many root-filled premolars and molars. A ceramic onlay is £750, or £675 for dental plan members. The tooth is scanned on our iTero Lumina, so there are no putty impressions, and it usually takes two visits: one to prepare and scan the tooth, and one to fit the onlay.
Crowns
A crown covers the whole tooth above the gum. It's the right choice when too little healthy tooth is left for a filling or an onlay to protect it: a tooth that has broken heavily, a cracked tooth that hurts when you bite, a large failing filling, a tooth worn down by grinding or acid, or a back tooth that has been root filled. Root-filled back teeth are more likely to crack, so a crown or onlay protects them.
Most of our crowns are ceramic, shaded to match your own teeth, so they look natural front or back. Ceramic crowns start from £675 on back teeth and £750 on front teeth. Gold is still a good choice for a back tooth if you grind heavily or there's little room, because it can be made very thin; gold crowns are priced on request. Every crown is made from a digital iTero Lumina scan, with no putty. Our dental crowns page has more.
What Each Option Costs
Fees are confirmed in your written plan before treatment starts, and dental plan members save 10% on fillings, onlays and crowns.2
| Treatment | Fee | Member |
|---|---|---|
| Tooth-coloured filling, front tooth, from | £105 | £95 |
| Tooth-coloured filling, back tooth, from | £118 | £106 |
| Ceramic onlay | £750 | £675 |
| Ceramic crown, back tooth, from | £675 | £608 |
| Ceramic crown, front tooth, from | £750 | £675 |
| Examination with X-rays, new patients | £70 | Included in your plan |
If a tooth needs root canal treatment first, that's priced separately; our root canal guide explains those fees. Treatment of £1,500 or more can be spread with interest-free finance, subject to status. See every fee.
What Happens at the Appointment
A filling is usually done in one visit. Onlays and crowns take two.
- Examination and X-ray. Your dentist checks the tooth, looks at the X-ray and explains whether a filling, onlay or crown is best, with the fee, before anything is done.
- Preparation and scan. The tooth is numbed and shaped under local anaesthetic, and any old filling and decay are removed. For an onlay or crown, the tooth is scanned on our iTero Lumina and a temporary protects it while yours is made.
- Fitting. The ceramic onlay or crown is tried in, checked for fit and colour, bonded in place, and your bite is adjusted so it feels right.
With a temporary in place, avoid sticky food, chew on the other side, and slide floss out sideways rather than pulling it up. If a temporary comes off, keep it and call us so we can put it back.
Making It Last
With good care, a crown typically lasts 10 to 15 years, and often longer; onlays and well-placed fillings can last many years too. What shortens their life is decay creeping in at the edges, gum disease and grinding. So the care is straightforward: brush twice a day, clean between your teeth every day, especially at the edges of the restoration, and keep your dental examinations so we can check those edges early.
If you grind or clench, a custom night guard, £210, protects your dental work as well as your teeth; our guide to teeth grinding explains the signs. Avoid biting ice, pens or nails. If a filling, onlay or crown ever chips or comes loose, keep any pieces and call us on 0141 248 1183. We keep same-day appointments every weekday for problems like this.
Questions
This guide is general information, not a diagnosis. A dentist needs to examine you to say what is right for your teeth.