--- title: "Crown vs Filling vs Onlay: Which Repair Fits Your Tooth?" description: "Dental crown vs filling vs onlay: learn how much damage each repair can handle, how long each lasts, and how a dentist decides. Sourced, plain-English guide." url: https://towncenterdental.multisites.ai/guides/crown-vs-filling-vs-onlay publisher: Town Center Dental phone: +1-636-273-5866 quote: https://towncenterdental.multisites.ai/request-appointment --- # Crown, filling or onlay: which does your tooth need? The size of the damage decides the repair. A filling fits small to medium decay. An inlay or onlay fits a tooth too damaged for a filling but too healthy for a crown. A crown covers the whole tooth when too little healthy tooth remains. Your dentist chooses after an exam. GuideUpdated October 26, 20268 min read 1. 1 ## Damage size decides Small to medium decay usually gets a filling. Heavier damage may call for an onlay or a crown. 2. 2 ## Onlay sits in the middle Cleveland Clinic says an onlay suits a tooth too damaged for a filling but too healthy for a crown. 3. 3 ## Crowns cover the whole tooth A crown makes sense when too little tooth remains to hold a filling, or when a cracked or root canal treated tooth needs protection. 4. 4 ## Lifespans vary Cleveland Clinic gives 10 to 20 years for fillings and five to 15 years for crowns. No range applies to every tooth. ## Which repair does my tooth need: a filling, an onlay or a crown? The amount of healthy tooth left decides the repair. A filling fits a small to medium cavity. An onlay fits a tooth with more damage. A crown fits a tooth that has lost too much structure to hold anything smaller. Your dentist makes the call after an exam and X-rays. This table shows the three repairs side by side. Filling Inlay or onlay Crown What it covers The cavity only A damaged area, and in the case of an onlay, one or more chewing points The whole visible tooth How it is made Placed directly in the tooth, often in one visit Made in a lab or milled, then bonded Made in a lab or milled, then bonded or cemented Visits Usually one Usually two, or one if made on site Usually two, or one if made on site Tooth removed Decayed tissue only Decayed tissue plus a little shaping A layer of enamel all around When it fits Small to medium damage More damage than a filling can hold, with healthy walls left Large damage, cracks, a root canal treated tooth, or a tooth that holds a bridge Cleveland Clinic describes the middle step this way: an inlay or onlay “fits into your existing tooth structure like a tiny puzzle piece.” The sections below take each repair in turn. ## What is a filling, and when is it enough? A filling replaces the part of a tooth lost to decay or a small chip. The dentist numbs the tooth, removes the damaged tissue, fills the space and shapes it. Cleveland Clinic notes that a direct filling needs only one visit. Common materials are amalgam (silver in color), composite resin (tooth-colored) and glass ionomer (tooth-colored). The ADA says your dentist considers the material on an individual basis, taking into account the size and location of the cavity. The [tooth-colored vs silver fillings guide](https://towncenterdental.multisites.ai/guides/tooth-colored-vs-silver-fillings) covers the choice in detail. A [filling](https://towncenterdental.multisites.ai/glossary/dental-filling) is enough when the tooth still has strong walls. If the cavity is wide, or if a crack runs through the tooth, a filling may not hold. A cavity found early is easier to treat. The [cavities guide](https://towncenterdental.multisites.ai/guides/cavities-explained) explains how decay grows and how it is found. ## What is an inlay or onlay? An [inlay](https://towncenterdental.multisites.ai/glossary/inlay) or [onlay](https://towncenterdental.multisites.ai/glossary/onlay) is a custom repair made outside the mouth and bonded into the tooth. Cleveland Clinic calls them common types of indirect fillings. They suit a tooth with too much damage for a filling and not enough damage for a crown. An inlay sits within the chewing surface. An onlay extends over one or more of the tooth’s points, called cusps. A 2022 review in Head & Face Medicine describes an onlay as a partial coverage restoration. It notes that when a lot of tooth structure is lost, onlays may rebuild the tooth’s contours better than a direct filling. The main idea is to keep more of your own tooth than a crown would. A crown requires a layer of enamel to be removed all around. An onlay removes less. Cleveland Clinic does not rank them, and neither will we. Your dentist will tell you which one the tooth can support. ## What is a crown, and when does it come into play? A crown is a cap that covers the whole visible tooth. It is the choice when the tooth is too weak or too broken for a smaller repair. The ADA says a crown can strengthen a tooth with a large filling when not enough tooth remains to hold the filling. Cleveland Clinic lists other reasons for a crown. They include protecting a cracked tooth, restoring a worn-down tooth, holding a bridge in place, covering a stained tooth, covering an implant and covering a tooth that had a root canal. The [dental crowns guide](https://towncenterdental.multisites.ai/guides/dental-crowns-guide) has types, lifespan and the visit steps. A crown is not always the last step. If a tooth is too decayed or broken for a crown to give a predictable result, Cleveland Clinic says the dentist may recommend removing it and replacing it with an implant. ## How do dentists decide? Dentists weigh the size of the damage, where the tooth sits and how it is used. They also look for cracks, decay under old fillings and the health of the nerve. These points steer the choice: - **How much healthy tooth is left.** This is the biggest factor. A thin wall of tooth around a big filling may crack. - **Which tooth it is.** Back teeth take heavy chewing force. Front teeth show in your smile. - **Cracks.** A crack may call for more coverage than a filling gives. - **Root canal treatment.** A tooth that has had a [root canal](https://towncenterdental.multisites.ai/glossary/root-canal-therapy) may be weaker. - **Grinding or clenching.** These habits add stress to any repair. - **Your goals and your plan.** Look, cost and insurance matter too. Ask the dentist to show you the tooth on the X-ray or on the screen. A good explanation names what is weak and why a smaller repair may fail. ## How long does each repair last? Cleveland Clinic gives different ranges for each. Fillings can last 10 to 20 years, depending on the material. Crowns average five to 15 years. The numbers are not a promise for any one tooth. A research review gave five-year survival numbers: up to 90.89 percent for inlays, 93.50 percent for onlays and 95.38 percent for crowns on back teeth. The authors pooled studies of different designs, so the numbers do not rank the repairs for your tooth. They suggest that all three can do well over five years. For tooth-colored fillings, NIDCR reports that among more than 700,000 tooth-colored fillings in the U.S., 16 percent failed within five years of being placed. The most common causes were new cavities and broken teeth. The ADA’s MouthHealthy site adds that no dental filling lasts forever. ## What does each one feel like? All three are done with local anesthetic, so the tooth is numb during the work. Afterward the tooth can feel sensitive. - **Filling.** Cleveland Clinic says minor sensitivity and gum soreness are normal and should fade in a week or two. A throbbing toothache, pain when you bite or lingering pain to heat or cold are reasons to call. - **Crown.** Cleveland Clinic says sensitivity for a couple of weeks is normal, but pain that keeps you up at night is not. - **Onlay.** Cleveland Clinic does not give separate numbers. Expect something close to a filling or a crown, and ask your dentist. Pain that grows worse is a reason to call. Do not wait for it to settle on its own. ## How are onlays and crowns made? Onlays and crowns are made outside the mouth, so they take more steps than a direct filling. Cleveland Clinic says most indirect fillings need two visits. At the first visit the dentist removes the damage, shapes the tooth and takes impressions. At the second visit the dentist bonds the finished piece in place. Crowns follow the same pattern. Cleveland Clinic says a lab usually needs two to three weeks, and a temporary crown covers the tooth meanwhile. Some offices use computer-aided design and milling, which can finish the piece in a single appointment. Cleveland Clinic notes that same-day crowns are not for everyone. Ask whether your tooth is a candidate. Town Center Dental’s technology page names an intraoral scanner and other tools the office uses. Ask which steps apply to your tooth and how many visits to plan for. ## What if an old filling is breaking down? An old filling can leak, crack or wear at the edges. The ADA’s MouthHealthy site says fillings may weaken over the years and tend to fracture and leak around the edges. Bacteria collect in the tiny gaps, and acid builds up there. Decay then forms under or beside the filling. Cleveland Clinic says to call your dentist right away if a filling breaks, or if you develop severe pain that does not go away with medication, a swollen face or jaw, or fever and chills. Those last signs can point to infection. Mayo Clinic says to go to an emergency room if you have trouble breathing or swallowing, or if you have a fever and facial swelling and cannot reach your dentist. If decay has spread under a filling, the dentist may replace it with a larger filling, an onlay or a crown. The exam and X-ray show which one the tooth can support. ## What are three common situations? These examples show how the choice often goes. They are general patterns, not medical advice for your tooth. What the dentist finds A repair that often fits A small to medium cavity with strong walls A filling A large cavity or an old filling that has failed, with healthy walls still standing An inlay or onlay A cusp has cracked, the walls are thin, or most of the tooth is gone A crown A tooth that just had a root canal and has little structure left A crown A tooth too broken for a crown to give a predictable result Removal, with a replacement discussed Your dentist may see something different once the decay is removed, so ask what the backup plan is. ## What should I ask my dentist? A few questions help you understand the recommendation: 1. How much healthy tooth would be left after the repair? 2. Why not a smaller repair? 3. What would an onlay mean for this tooth? 4. Which material do you suggest and why? 5. How many visits will it take, and will I wear a temporary? 6. What will my insurance cover, and what is the estimate? 7. What are the signs I should call you about afterward? ## What about cost and insurance? A filling has fewer steps and no lab work, while an onlay or crown adds impressions and a lab-made piece. Cleveland Clinic lists “may be expensive” as a drawback of crowns. The ADA adds that composite fillings cost more than amalgam and occasionally are not covered by some insurance plans. Town Center Dental does not publish prices. The office gives each patient their own estimate after an exam. Ask for the estimate before you choose, and ask what each option would mean for insurance. ## Next step If you are not sure what your tooth needs, start with an exam and ask for the options in writing. Read about [dental fillings](https://towncenterdental.multisites.ai/services/dental-fillings) and [dental crowns](https://towncenterdental.multisites.ai/services/dental-crown) at Town Center Dental, then call (636) 273-5866 or [request an appointment](https://towncenterdental.multisites.ai/request-appointment). ## Frequently asked questions ### Is a crown or a filling better after a root canal? A root canal treated tooth often has less structure left, so a crown is a common choice. Cleveland Clinic lists covering a root canal treated tooth as a reason for a crown. A filling may be enough if a lot of tooth remains. Your dentist will decide after looking at the tooth. ### How much more does a crown cost than a filling? A crown has more steps than a filling, including impressions and a lab-made cap. Cleveland Clinic lists cost as a possible drawback of crowns. Town Center Dental gives each patient their own estimate after an exam. We do not publish prices. ### Why do dentists push for crowns? Dentists recommend a crown when a filling is unlikely to hold. The ADA says a crown can strengthen a tooth with a large filling when not enough tooth remains to hold the filling. You can ask to see the X-ray, and you can ask about a smaller repair. ### Does a crown hurt more than a filling? Both are done with local anesthetic. Cleveland Clinic says a crown should not hurt during the work, and some sensitivity for a couple of weeks is normal. It describes sensitivity after a filling as minor and gone in a week or two. Call your dentist about pain that keeps you up. ### What is an onlay? An onlay is a lab-made repair that fits into a damaged tooth like a puzzle piece and covers one or more of its chewing points. Cleveland Clinic says dentists use it when a tooth has too much damage for a filling but not enough to warrant a crown. ## Terms on this page - [Cavity (dental caries)](https://towncenterdental.multisites.ai/glossary/cavity-dental-caries) - [Intraoral scanner](https://towncenterdental.multisites.ai/glossary/intraoral-scanner) - [Local anesthetic](https://towncenterdental.multisites.ai/glossary/local-anesthetic) - [Composite resin](https://towncenterdental.multisites.ai/glossary/composite-resin) - [Temporary crown](https://towncenterdental.multisites.ai/glossary/temporary-crown) - [Dental filling](https://towncenterdental.multisites.ai/glossary/dental-filling) - [Glass ionomer](https://towncenterdental.multisites.ai/glossary/glass-ionomer) - [Toothache](https://towncenterdental.multisites.ai/glossary/toothache) - [Enamel](https://towncenterdental.multisites.ai/glossary/enamel) - [Inlay](https://towncenterdental.multisites.ai/glossary/inlay) ## Sources 1. [Cleveland Clinic: Dental Fillings: Types, Materials & What They're For](https://my.clevelandclinic.org/health/treatments/17002-dental-fillings) 2. [Cleveland Clinic: Dental Crowns: Types, Procedure & Care](https://my.clevelandclinic.org/health/treatments/10923-dental-crowns) 3. [ADA MouthHealthy: Crowns](https://www.mouthhealthy.org/all-topics-a-z/crowns) 4. [Head & Face Medicine (PMC): Onlays/partial crowns versus full crowns in restoring posterior teeth, a systematic review and meta-analysis](https://pmc.ncbi.nlm.nih.gov/articles/PMC9677648/) 5. [ADA MouthHealthy: Dental Filling Options](https://www.mouthhealthy.org/all-topics-a-z/dental-filling-options) 6. [Mayo Clinic: Tooth abscess, symptoms and causes](https://www.mayoclinic.org/diseases-conditions/tooth-abscess/symptoms-causes/syc-20350901) Written by Town Center Dental and checked against the sources above on October 26, 2026. Dental guidance changes, so check the linked page, and ask your dentist about your own care. ## Keep reading - [Dental crowns: types, lifespan and what to expectA dental crown is a tooth-shaped cap that covers a weak, broken or worn tooth. Cleveland Clinic gives an average lifespan of five to 15 years. Metal, porcelain and resin crowns differ in look and wear. Most crowns take two visits, and your dentist numbs the tooth first.](https://towncenterdental.multisites.ai/guides/dental-crowns-guide) - [Tooth-colored vs silver fillings: which is better, and should old ones be replaced?Neither filling is better for every tooth. Silver amalgam is strong and costs less. Tooth-colored composite blends in but may need replacing sooner. Your dentist weighs the size and spot of the cavity. The FDA does not advise removing intact silver fillings just to swap them.](https://towncenterdental.multisites.ai/guides/tooth-colored-vs-silver-fillings) - [Cavities explained: causes, decay without pain and treatmentYes, you can have a cavity without pain. NIDCR says early tooth decay usually has no symptoms, so dentists find it at checkups and on X-rays. Very early enamel damage can sometimes be stopped with fluoride. Once a hole forms, the usual treatment is a filling.](https://towncenterdental.multisites.ai/guides/cavities-explained) - [Inlay vs Onlay vs Crown: How Dentists Choose Between ThemAn inlay fills the area between the cusps of a tooth. An onlay also covers at least one cusp. A crown covers the whole tooth. Dentists often think of inlays and onlays as a middle step between a filling and a crown. Your dentist picks based on how much healthy tooth is left.](https://towncenterdental.multisites.ai/blog/inlay-vs-onlay-vs-crown) - [Why Does My Tooth Hurt After a Crown or Filling?Mild sensitivity and gum soreness after a filling or crown are common and often fade in a week or two. A bite that feels high, a throbbing ache, or pain that lingers after hot or cold needs a call to your dentist. Do not wait if swelling or fever appears.](https://towncenterdental.multisites.ai/blog/why-does-my-tooth-hurt-after-a-crown-or-filling) - [Dental Emergencies: What Counts, What To Do First, and Who To CallA dental emergency is a mouth problem that needs care right away, such as uncontrolled bleeding, severe pain that medicine does not ease, or a knocked-out tooth. Call 911 or go to an emergency room for trouble breathing or swallowing. Otherwise, call your dentist. Town Center Dental is closed Friday to Sunday.](https://towncenterdental.multisites.ai/guides/dental-emergency-guide) ## Ready when you are [Request an appointment](https://towncenterdental.multisites.ai/request-appointment)[Call (636) 273-5866](tel:+1-636-273-5866)