A crown covers a tooth completely. It is what we reach for when there is no longer enough sound tooth left to hold a filling, or when a tooth has cracked and needs to be held together rather than patched.
It is also the point where a tooth stops being repaired and starts being rebuilt, and that is worth saying plainly at the top: a crown is not reversible. Preparing a tooth for one removes structure that does not grow back. That is not an argument against crowns, which are one of the most reliable things in dentistry. It is an argument for being sure you need one.
When a crown is the answer, and when it is not
The first question we ask is whether something smaller will do.
A crown earns its place when:
- An old filling is failing and there is now more filling than tooth.
- The tooth has cracked, or carries a crack line that will keep propagating every time you bite.
- The tooth has had a root canal, particularly a back tooth doing heavy chewing.
- Wear has taken enough height that the tooth no longer meets its opposite number properly.
It is the wrong answer when a filling or a more conservative restoration would rebuild what is missing and leave the rest of the tooth standing. Those get considered first, and if one will work we will tell you so.
Our bias runs toward keeping tooth structure. Enamel is the one part of your mouth that cannot be manufactured, and every crown is a permanent trade of some of it for strength and protection. A trade worth making on a cracked molar is not worth making on a tooth that simply needs a good filling.
Why we stopped making crowns in this office
In 2000 we bought the first CEREC machine in Las Vegas. For years afterward we designed and milled crowns here, chairside, and seated them in a single visit. We know the technology well, because we were using it before most of the profession had seen one.
We do not do it any more, and the reason is the bite.
A crown is not just a cap on a tooth. It is a brand new chewing surface, and where that surface meets the opposing tooth, and how it behaves when your jaw slides sideways, is not a detail. Get it a fraction high or in the wrong place and the consequences do not stay local to the tooth. They turn up in the muscles and the joint, which is a large part of what this practice spends its time on.
Two things convinced us to hand the making of the crown back to a laboratory.
- A technician can match the material to the situation. Working with a skilled lab means the crown is made from whatever suits that particular tooth, in that particular bite, by someone whose entire job is making crowns well.
- The temporary is doing real work. It is not a placeholder to keep you comfortable until the good one arrives. It is a trial run. You chew on it, and if something is high or feels wrong, we find out before anything is cemented permanently. In our hands that has meant markedly fewer bite and joint problems than we had to manage in our single-visit years.
This is a preference, not a verdict. Same-day dentistry is good technology and plenty of dentists do excellent work with it. This is simply what we found works better in our hands, for our patients, and for the kind of bites we see most.
What about an onlay?
Preserving tooth structure was the whole point of buying that machine. An onlay rebuilds the part of the tooth that is missing and leaves the walls of the tooth standing, instead of taking the whole thing down, and we placed a great many of them. Plenty are still in service more than twenty years later.
We have moved toward full coverage for most of our patients since then, and the reason is not that onlays fail.
The published comparisons are thin. A 2022 systematic review and meta-analysis found no statistically significant difference in survival between onlays and full crowns on back teeth at one year or at three, and the longest-running study it included actually favored the onlays. But it pooled five observational studies alongside a single randomized trial, over short follow-up periods, so it is not strong evidence in either direction.
Wang B, Fan J, Wang L, Xu B. Onlays/partial crowns versus full crowns in restoring posterior teeth: a systematic review and meta-analysis. Head Face Med. 2022;18(1):36. The authors conclude that onlays performed as well as full crowns in the posterior region over the short term, and call for randomized trials with long-term follow-up.
The real reason is the mouths we mostly see. By the time someone arrives here their teeth have often been wearing down for years, and on a worn tooth there is frequently not enough sound structure left for partial coverage to be the conservative choice it was designed to be.
So it comes down to where you are in life, and to the tooth in front of us. A young tooth with a failing filling and good structure still around it is exactly what an onlay is for, and we still place them. A worn dentition being rebuilt to a new bite is a different problem, and full coverage answers that one better. This is a clinical decision made tooth by tooth, not a house policy.
The material gets chosen for the tooth
Three materials cover very nearly everything we do. That short list is deliberate.
- Zirconia. The strongest of the three, and what we generally want on back teeth, on heavy grinders, and anywhere the forces are high enough that a weaker material would be asking for trouble.
- e.max, pressed lithium disilicate. The best-looking, with enough strength for most situations. This is usually the choice toward the front of the mouth, where a crown has to disappear next to the teeth around it rather than merely survive.
- Gold. Still, quietly, the longest-serving material in dentistry. It needs the least tooth removed because it can be made thin, it seals beautifully at the margin, and it wears at a rate close to enamel, which makes it kind to the tooth biting against it. The one thing wrong with gold is that it looks like gold, which is why it lives at the back of the mouth or not at all.
Which one suits your tooth is a conversation, not a default, and it is worth having before the tooth is prepared rather than afterward.
What having one made is actually like
Two appointments, a couple of weeks apart.
- The first visit. The tooth is numbed and prepared, we record the prepared tooth and the way your bite closes, and you leave in a well-made temporary. This visit usually takes longer than people expect, because the preparation and those records are what decide whether the final crown fits.
- In between. Chew on it. This is the part patients tend to treat as dead time, and it is not. If the temporary feels high, catches when you slide sideways, or the tooth aches afterward, call us. That information is far more useful now than it is after the final crown is cemented.
- The second visit. The temporary comes off, the crown is tried in, and we check the fit, the contacts either side and the bite in every direction before anything is cemented. Then it goes on.
Scan or impression? Usually a digital scan, the same scanning technology we use at your exam, which means no tray and nothing to gag on. We have kept conventional impression material for the cases where a scan struggles, and for the ones where it is simply the more straightforward way to get an accurate record. What matters is the accuracy of the record, not which tool produced it.
After a root canal
A back tooth that has had root canal treatment usually needs a crown afterward, and this is the sequence people are least prepared for. A root-treated tooth has had its inside hollowed out and has often lost a good deal of structure to the decay or fracture that made the treatment necessary. What is left is more brittle and splits more easily under chewing load.
The crown is what stops that. We plan it as part of the same course of treatment rather than as a separate surprise, and we will tell you at the start that it is coming, because a root canal and a crown on one tooth is a real sequence with a real cost and you should hear about it up front. Our article on dental insurance covers why that particular combination tends to exhaust an annual maximum on its own.
How long a crown lasts
A well-made crown on a well-looked-after tooth lasts a long time, frequently more than a decade and often considerably longer. But it is worth understanding what actually ends one, because it is rarely the crown itself.
- Decay at the margin. The crown does not decay. The tooth where the crown meets it can, and that is the most common reason a crown is replaced. Caught early enough, that is sometimes a small composite repair rather than a new crown.
- The bite. A crown taking more force than it should, or landing wrong in a sideways movement, will chip or loosen. This is the failure we work hardest to design out.
- The tooth underneath. Sometimes the crown is fine and the root or the gum around it is not.
None of that is a reason to hesitate. It is the reason your crowns get looked at during your hygiene visits, and X-rayed on a regular schedule. How often depends on what is in your mouth. Every year or two is typical, but once someone has a number of crowns we would rather take X-rays annually, simply because there are that many more margins to keep an eye on. A margin that is starting to leak is a small repair when it is found early, and a much bigger one when it is found because the tooth started hurting.
If you have been told you need a crown
Bring the plan and we will go through it with you: whether the tooth genuinely needs full coverage, what it would take to keep more of it, which material suits the situation, and what the sequence and the cost look like before anything starts. Call us at 702-734-0776.