A look at the lifespan of crowns and bridges through survival rates by material, why debonding, fracture, decay at the margin and gum recession occur, and what the director checks after fitting.
Director Jeong Jinwoo · Published 2026.10.08
Summary. A crowned tooth is not permanent. The proportion of single crowns still in place after 5 years is about 92–97% depending on the material, and after that, debonding, fracture, decay at the margin and problems with the nerve inside gradually accumulate. A bridge ties two abutment teeth into one structure, so decay in one tooth determines the lifespan of the whole. What extends lifespan is not so much the material itself as the height of the remaining tooth, the bite, and cleaning at the margin. This guide also describes how we check those three things before treatment.
In a systematic review pooling studies of single crowns, 5-year survival was reported as about 94.7% for metal-ceramic (PFM), about 96.6% for glass-ceramics such as lithium disilicate, and about 92.1% for zirconia.[1] Survival is “the proportion still in the mouth,” so cases where a little porcelain chipped off or the crown was recemented also count as “surviving.” In the same study, zirconia crowns frequently had technical problems such as chipping of the outer porcelain and were not recommended as a first choice. However, much of this data is from older zirconia veneered with porcelain, and recent monolithic zirconia has a short follow-up period.[6]
| Prosthesis | Survival rate (literature) | Most common problems | Notes |
|---|---|---|---|
| Metal-ceramic crown (PFM) | About 94.7% at 5 years[1] | Porcelain fracture, dark line at the gum margin | A long-proven material |
| Glass-ceramic crown (e.max, etc.) | About 96.6% at 5 years[1] | Fracture (especially in molars) | Favorable for front teeth and premolars |
| Zirconia crown | About 92.1% at 5 years[1] | Porcelain chipping (when veneered), wear of opposing teeth | Data on monolithic zirconia is short-term[6] |
| Ceramic laminate veneer | Cumulative 89% at about 9 years of follow-up[5] | Fracture or chipping about 4%, debonding about 2% | Thin, so usually remade if broken |
| Bridge | No comparable survival rate on the same basis in this literature (only complication frequencies reported)[2] | Decay of abutment teeth, need for root canal treatment, debonding | The condition of the abutment teeth determines lifespan |
The figures in the table are not absolute values because study participants and criteria differ, and even with the same material, results vary with position, bite and care.
The main reason a crown comes off is not weak cement, but that the tooth holding the crown is too short or too narrow. A crown stays in place by the grip it has around the remaining tooth (retention), and if the tooth is short, it lifts every time force is applied, no matter how good the cement.[4] So if a tooth is badly broken down or hollowed out by root canal treatment, we build up a core with a post and core (Korean), and secure a ferrule (Korean) so that 1.5–2mm of tooth remains above the gum, or adjust the gum level with crown lengthening (Korean).
A crown that has come off can be recemented if both the tooth and the crown are intact. But if the tooth inside is decayed or the inside of the crown no longer fits, it will soon come off again even if recemented, so we first look at why it came off. The Prosthesis debonding (Korean) entry summarizes when it can and cannot be recemented.
Fracture is a matter of material limits and force; decay at the margin is a matter of cleaning. Porcelain is hard but brittle, so it cracks if there is tooth grinding (Korean) or clenching, or if the bite is concentrated on one point. In single crowns, porcelain fracture is reported as one of the main complications.[2] If only a little of the outer porcelain has chipped off, it is smoothed or repaired; if the body itself is broken, a new one is made.
Decay at the margin is when plaque remains along the line where the crown meets the tooth and the tooth beneath decays. The crown itself does not decay, but the tooth inside it does. In bridges this is the most common complication, and decay in a single abutment tooth means the entire bridge has to be remade.[2] Because it cannot be seen from outside, it is found with X-rays and probing at regular checkups. We take particular care where the margin sits deep below the gum or where floss catches.
Sensitivity for a few days right after fitting is common and usually settles. If it lasts more than a few weeks or hurts when you chew, the bite may be high or a problem may have developed in the nerve inside. Grinding down a tooth for a crown irritates the nerve, and over time the nerve may die. This is why “needing root canal treatment later” is reported as one of the main complications of single crowns.[2] In that case, root canal treatment is done through a hole made in the crown, which is then filled, or a new crown is made.
Conversely, a tooth that has already had root canal treatment needs a crown. One study found that teeth left without a crown after root canal treatment had about 6 times the risk of tooth loss compared with crowned teeth.[3] This is because a hollowed-out tooth splits under chewing force. A detailed explanation is in Crowns after root canal treatment (Korean).
Gums gradually recede with age and brushing habits, and when they do, the crown margin is exposed. With a metal-ceramic crown, the metal rim shows and looks like a dark line; with ceramic, the margin is less noticeable even when exposed. This is not a failure of the crown but a change in the gum, so for visible sites such as the front teeth, we decide from the start where to place the margin together with the choice of material. Tooth roots exposed by gum recession are sensitive and prone to decay, so we look at the care of this area as well.
Before you decide on a crown or bridge, Joy Dental Clinic Bongcheon reviews X-rays and intraoral photos together with you and checks the items below. Most of the conditions that determine lifespan are set at this stage.
| Item checked | Why we look | What changes depending on the result |
|---|---|---|
| Height and thickness of the remaining tooth | Whether there is enough for the crown to hold onto[4] | Post and core, crown lengthening, extraction followed by an implant |
| Nerve condition | Whether nerve problems are likely after crowning | Whether root canal treatment is done first |
| Root length and jawbone (bridge abutments) | Whether they can withstand the force of two teeth | Bridge vs implant |
| Bite and signs of tooth grinding | Whether the site takes forces that could cause fracture | Choice of material, night guard |
| Where to place the margin | Whether it can be cleaned, whether it is visible | Material, gum treatment |
| Neighboring and opposing teeth | Whether gaps will form where food can get caught | Contact point design |
We check for hidden decay and cracks before preparing the tooth with Q-ray, take impressions with the TRIOS 6 intraoral scanner, and look at the bite together on screen. The pros and cons of each material are summarized in the Zirconia crown (Korean), Metal-ceramic crown (Korean) and e.max crown (Korean) entries.
One to two weeks after fitting, we check the bite and sensitivity, and after that, at checkups every 6 months, we look at decay at the margin, early signs of debonding, porcelain fracture and gum condition. At each checkup we look at three things: whether the area below the margin has darkened on the X-ray (decay), whether the crown moves slightly when pressed or catches floss (early signs of debonding or a gap at the margin), and whether there is wear or cracking on the opposing teeth and porcelain surface (a force problem).
If we see a problem, we tell you first. Decay at the margin found while small can be handled with a partial repair, but if it goes deep beneath the crown, the crown must be remade or the tooth may be lost. At home, the most important thing is cleaning the crown margin every day with floss or an interdental brush, and if you grind your teeth, an occlusal splint (night guard) (Korean) reduces fractures.
Regular crowns, bridges and laminate veneers are non-covered items not covered by Korean national health insurance. The exceptions are parts included in covered prostheses, such as the crown of a covered implant for patients aged 65 or older (metal-ceramic, including zirconia since February 2025) and the artificial teeth of a covered denture.
The cost of repair or remaking depends on the material, extent and number of teeth, and recementing a crown that came off and making a new one differ greatly in cost and time, so this is explained at the consultation after diagnosis. For prostheses done at Joy Dental Clinic Bongcheon, checks and simple adjustments are carried out as part of regular checkups. This varies individually and is explained after a detailed diagnosis and consultation.
In the following cases, we consider other approaches before a crown or bridge.
My crown came off. Can it just be recemented? If both the tooth and the crown are intact, it is cleaned and recemented. If the inside is decayed or the crown does not fit, it will soon come off again even if recemented, so we look at the cause first. Do not throw away a crown that came off; bring it with you.
My crowned tooth is sensitive. Is that normal? It is common for a few days right after fitting. If it lasts more than a month or hurts with hot things, it may be a nerve problem and needs to be checked.[2]
Only that tooth hurts when I chew. The most likely cause is a high bite. Adjustment takes only a few minutes, and if it still hurts after adjustment, we look for a crack in the tooth or a nerve problem.
It’s been more than 10 years. Should I replace it? If there is no discomfort and the checkup shows no decay at the margin, gaps or fracture, there is no particular reason it must be replaced. We judge by condition rather than by age.
Does zirconia last the longest? It is hard but not unbreakable, and in the literature, porcelain-veneered zirconia frequently chipped.[1] Depending on the site and bite, another material may be better.
What material is good if I grind my teeth? For molars that take a lot of force, we consider metal or monolithic zirconia rather than brittle ceramic, and regardless of material, we recommend a night guard.
I was told the crown margin is decayed, but the crown looks fine. The crown does not decay, but the tooth beneath it does. If it is small, a partial repair; if it is deep beneath the crown, remaking or root canal treatment is needed.[2]
Only one abutment of my bridge has a problem. Does the whole thing need to be replaced? A bridge is a single piece, so it is hard to detach and fix just one side. If the abutment tooth can be saved, the bridge is sometimes cut and only part of it remade, but usually remaking the whole bridge or switching to an implant is considered.
Does a root-canal-treated tooth have to get a crown? For molars, we recommend it. One study found that teeth left uncrowned had about 6 times the risk of tooth loss.[3] For front teeth, depending on how much tooth remains, they are sometimes filled without a crown.
The gum side of my crown looks dark. The gum may have receded and exposed the metal rim, or the area below the margin may be decayed. The two are treated differently, so we distinguish them in the clinic.
There’s a smell coming from inside my crown. This is common when food gets caught in a gap at the margin or there is decay beneath it. A spot where floss catches or shreds is a sign that there is a gap.
My temporary crown came off. A temporary crown is attached with weak cement and can come off. If the tooth is exposed it can be sensitive and the neighboring teeth can shift, so we recement it quickly.
My laminate veneer broke. Can it be reattached? Small chips are sometimes repaired with resin, but because of its thin structure, it is usually remade. Fracture and chipping are the most common problems with laminate veneers.[5]
Does getting a crown weaken the tooth? The tooth is reduced by as much as is ground away. That is why, for small decay, we first consider an inlay or resin instead of a crown, and if a crown is needed, we design it to preserve as much of the remaining tooth as possible.[4]
My crown’s color now differs from the teeth around it. Ceramic does not discolor, but if the surrounding natural teeth become stained or brighter from whitening, a difference appears. A detailed explanation is in Color mismatch in front-tooth prostheses (Korean).
Food gets caught under my bridge. The space under a bridge is a place that needs cleaning to begin with. Clean it every day with bridge floss or an interdental brush, and if the gap has grown, a change in the jawbone has created the space, so we check it at your checkup.
This guide was written and reviewed by Director Jeong Jinwoo of Joy Dental Clinic Bongcheon (board-certified prosthodontist and specialist in integrated dentistry) based on standard dental knowledge. At Joy Dental Clinic Bongcheon, the director personally handles everything from diagnosis and treatment to regular maintenance afterward. We are right next to Exit 1 of Bongcheon Station on Line 2, and directions from Seoul Nat’l Univ., Sillim, Nakseongdae and Sadang Stations are in Directions.
This article is for general information and does not replace a diagnosis or treatment plan for your individual condition. The lifespan and side effects of prostheses differ individually and are explained after a detailed diagnosis and consultation.
RESERVATION
This article provides general information. An accurate diagnosis and treatment plan are given through consultation.
33 m from Exit 1, Bongcheon Station (Line 2) · Directions from Bongcheon Station →
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