Santé bucco-dentaire

Broken molar: 4 solutions and when to see the dentist

Molar broken by decay or an impact: solutions for repairing it (composite, crown, extraction), emergency steps, and when to see a dentist.

Publié le 24/05/2022 Mis à jour le 19/09/2026 14 min de lecture Relu par l'équipe Y-Brush

Comment réparer une molaire cassée par la carie ? - Y-Brush

Sommaire de l'article+

A molar broken by a cavity is never insignificant: as soon as you notice a missing piece, a crack or pain, the right thing to do is to make a dentist's appointment without delay, because only professional care can prevent the condition from worsening (infection, abscess, tooth loss). While waiting for your appointment, a few simple steps can relieve the pain and protect the tooth. This guide explains why a molar breaks, how it is repaired depending on the severity (composite filling, crown, extraction followed by an implant), and how to prevent it from happening again.

key takeaways

A molar broken by a cavity must be examined promptly by a dentist: it will not repair itself, and its fragility worsens over time.
Depending on the extent of the damage, treatment may range from a simple composite filling to a crown, or even extraction followed by an implant.
Severe pain, a deep fracture, bleeding or an exposed pulp (nerve) are signs of an emergency: you must see a dentist the same day.
While waiting for your appointment, avoid chewing on the affected side, rinse with warm salt water and relieve the pain with a suitable painkiller.
Cavities remain the leading cause of fractures: thorough brushing of the molars and regular check-ups significantly reduce the risk of recurrence.

What exactly does it mean to have a cavity in a molar?

A cavity is the gradual destruction of the enamel and then the dentin, caused by the acids produced by bacteria in dental plaque. On a molar, this process is particularly insidious: hollowed out from the inside, the tooth loses its strength, and even a slightly hard meal can then break off a fragment. This is why a broken molar is very often the result of a cavity that has been ignored for months. To understand in detail how this process develops and how to stop it, see our complete guide to dental cavities.

Molars are the teeth most affected by cavities, because they are the hardest to clean: located at the back of the mouth, they have deep grooves where plaque easily accumulates. If you often get a cavity in this area, several points should be checked:

Make sure your toothbrush is suited to the size of your jaw: if it is too large, it cannot reach the back molars properly and cleans them incompletely.
Limit snacking: every sugary snack triggers acid production again, and plaque that builds up between meals encourages new cavities to develop.
That dental floss or a water flosser complement brushing, because cavities often start between two molars, where a toothbrush cannot reach.

When the second molar is decayed and a wisdom tooth is too close against it, it becomes difficult to treat the decay properly. The wisdom tooth may then need to be extracted to allow the damaged molar to be treated. Only a clinical examination, supplemented by an X-ray, allows the dentist to assess the situation.

Conseils d’hygiène bucco-dentaire Y-Brush

Rejoignez le club !

Obtenez des conseils personnalisés pour une meilleure hygiène dentaire

Je me brosse les dents avec plaisir Je me brosse les dents parce qu'il le faut

Definition. A broken molar can refer to anything from a small chip in the enamel to a deep fracture reaching the root. The severity, and therefore the treatment, depends on the depth of the break and whether or not the pulp (the tooth's nerve) is exposed.

Broken molar: what to do in an emergency?

A molar that breaks is not always a life-threatening emergency, but it almost always requires prompt dental care. The first thing to do is stay calm and assess the situation: is the tooth simply chipped, or is it deeply cracked? Is there severe pain, bleeding, or a piece of exposed gum? These factors indicate the level of urgency.

Certain signs require contacting a dentist the same day, or an emergency dental service if the practice is closed. Do not face worsening pain alone: an untreated infection can spread and become serious.

By contrast, a small painless chip does not require rushing to the emergency room, but it still warrants an appointment soon: a weakened molar will break a little more with each bite until it is protected.

What to avoid. Never try to file down, glue back together, or fill a broken molar yourself, and do not place aspirin directly on the tooth or gums (risk of burns). These actions often make the situation worse and complicate the dentist's repair.

Here are the signs that should prompt you to seek urgent care:

Severe or throbbing pain, especially if triggered by hot, cold, or chewing.
A deep fracture revealing a darker or pinkish area in the center of the tooth: the pulp (the nerve) may be exposed.
Persistent bleeding, swelling of the cheek or gums, or the appearance of an abscess (a painful lump).
A fever or persistent bad taste in the mouth, which may indicate an infection.

How is a broken molar repaired? Dental treatments

Good news: in the vast majority of cases, a broken molar can be repaired. The dentist chooses the method based on the extent of the fracture, whether or not the nerve is affected, and the condition of the root. The sooner it is treated, the more conservative options (which preserve the tooth) remain possible.

It always begins with an examination and an X-ray to assess the depth of the fracture and the condition of the root. This diagnosis determines the treatment: the priority is to preserve the tooth, and extraction is considered only as a last resort.

Here are the main options, from the simplest to the most extensive. They are not mutually exclusive: the same case may involve, for example, root canal treatment followed by a crown.

Polishing

For very minor damage, when only a small fragment of enamel has chipped off. The dentist smooths the surface, removes sharp edges, and restores the tooth to a comfortable shape in a single appointment.

The composite (filling)

For small to medium-sized fractures. The missing part is rebuilt with a tooth-colored composite resin, often in a single visit. This is the most common repair after a cavity.

The inlay or onlay

A custom-made restoration fabricated in a laboratory and then bonded to fill a more substantial loss of tooth structure. Stronger than a large composite filling, it is indicated when a significant part of the molar has been destroyed.

The crown

When the fracture affects a large part of the tooth, a crown completely covers the molar to restore its shape and function. If the nerve is affected, it is placed after root canal treatment.

Root canal treatment

When the pulp (the nerve) is exposed or infected, the dentist removes the nerve, disinfects the area, and then fills the canals. The devitalized tooth is subsequently protected with a crown because it becomes more fragile.

Extraction followed by an implant

Reserved for deep root fractures that cannot be repaired. The tooth is removed and, in most cases, replaced with an implant or a bridge to restore chewing function and prevent neighboring teeth from shifting.

Worth noting. A root-treated or crowned molar is still a real tooth that needs care: decay can recur at the junction with the gum. Brushing and check-ups remain essential even after repair.

How much does it cost to repair a broken molar?

The cost of a broken molar depends on the solution chosen by the dentist and your coverage. As an indication, and before reimbursement, here are the usual price ranges in France:

Composite (filling): from a few dozen euros to approximately €100, depending on the extent of the fracture. This is the most common repair and is partially covered by Health Insurance.
Inlay or onlay: approximately €250 to €600, depending on the material (composite or ceramic) and the size of the restoration.
Crown: approximately €400 to €1,200. Some molar crowns are covered by the 100% Santé scheme and are then fully reimbursed, with no out-of-pocket cost.
Root canal treatment (devitalization): approximately €100 to €400, partially reimbursed, plus the cost of the crown that subsequently protects the tooth.
Extraction: approximately €30 to €120 for a simple extraction.
Implant with crown: approximately €1,500 to €3,000. The implant is not reimbursed by the French Health Insurance system, but many insurance plans contribute toward the cost.
Bridge: approximately €900 to €2,000, depending on the number of teeth concerned.

These amounts are indicative only: only a quote prepared by your dentist, taking into account the 100% Santé scheme and your insurance, can determine your actual out-of-pocket cost.

Good to know. Repairing the tooth early is almost always less expensive: a composite filling placed in time can avoid a crown, and a crown placed in time can avoid extraction followed by an implant, the most expensive option. Consulting promptly therefore protects your tooth as well as your budget.

What should you do while waiting to see the dentist?

Between the moment the molar breaks and your appointment, a few precautions can limit the pain and protect the tooth. They do not replace treatment, but they help prevent the fracture from worsening or an infection from developing.

The aim is twofold: to relieve the pain and avoid making things worse. Keep the area clean, spare the tooth and monitor how the pain develops. If a piece of tooth has come off, keep it in a little milk or saline solution and bring it to the dental office: it may sometimes be reusable.

Here are the useful steps to take as soon as possible:

Rinse gently. A mouthwash made with lukewarm, slightly salted water cleans the area and soothes the gums. Avoid very hot or very cold water if the tooth is sensitive.
Relieve the pain. An appropriate painkiller, such as paracetamol, may be taken according to the recommended dosage. Ask your pharmacist for advice and avoid placing medication directly on the tooth.
Protect the tooth. Chew on the other side and choose soft, lukewarm foods. Avoid hard, sticky, very sweet, hot or iced foods, which can trigger the pain.
Reduce the swelling. If your cheek is swollen, applying a cold compress to the outside at intervals can help limit inflammation while you wait for your appointment.
Monitor the situation and seek care. If the pain, swelling or fever worsens, do not wait: contact a dentist or an emergency service without waiting for the scheduled appointment.

Why do molars break?

Understanding the cause of the fracture helps prevent recurrence. Several situations can weaken and then break a molar, either alone or in combination:

Tooth decay, by far the most common cause: it eats away at the tooth from the inside until the wall gives way.
Bruxism, the involuntary grinding or clenching of the teeth, often at night, which wears down and cracks the enamel.
An impact from a fall or contact sport, more common in children, adolescents and athletes.
Misaligned teeth or the loss of a neighboring tooth, which places excessive stress on the remaining molars.
Old, large fillings, which weaken the tooth walls over time.

Among these causes, tooth decay remains the most insidious: many patients do not notice it until the tooth is already seriously compromised. Hence the importance of regular check-ups, which make it possible to detect it before the tooth breaks.

How can you prevent a molar from breaking due to tooth decay?

The best repair is the one you avoid. Since tooth decay is the main culprit, rigorous oral hygiene is the most effective protection. The idea is simple: prevent plaque from building up, especially on the back molars, which are more exposed.

Thorough brushing twice a day for two minutes with fluoride toothpaste and a soft-bristled toothbrush remains the foundation. Floss or a water flosser completes cleaning between the teeth, where cavities often start. A low-sugar diet and quitting smoking also support the health of your molars.

For molars that are difficult to reach, a sonic toothbrush can help dislodge more plaque without damaging the enamel: our Y-Brush sonic toothbrush, with its Y-shaped design, cleans both sides of each jaw in ten seconds and makes regular, thorough brushing easier, including at the back of the mouth. In our clinical studies, it proved to be 2× more efficient than traditional electric toothbrushes, making it easier to clean the back molars completely, where most of the cavities responsible for fractures develop.

A few simple rules significantly reduce the risk of tooth decay and therefore fractures:

A low-sugar diet, limiting snacking between meals.
Regular brushing from an early age, after meals, for two minutes, with fluoride toothpaste.
Daily use of floss for older children and adults, preferably in the evening.
A visit to the dentist at least once a year for a check-up and scaling.
An appropriate fluoride intake, which strengthens enamel and makes it more resistant.
Protection in cases of bruxism (night guard) or contact sports (mouthguard), as recommended by your dentist.

Y-Brush advice. Spend a few extra seconds on your back molars, which are the most often overlooked when brushing. This is where most of the cavities that cause fractures develop, and thorough cleaning in this area makes a real difference over the long term. Daily sonic brushing, 2× more efficient than traditional electric toothbrushes, helps you do this without any extra effort.

Frequently asked questions about broken molars

Can a broken molar be repaired?

A broken molar can be repaired in the vast majority of cases, provided you seek care promptly. Depending on the severity, the dentist may recommend a composite, an inlay/onlay or a crown; only deep root fractures sometimes lead to extraction followed by an implant. The earlier treatment begins, the more conservative options remain possible.

What should you do in an emergency when a molar breaks?

If a molar has just broken, the right thing to do is to rinse with warm salt water, avoid chewing on the affected side and contact a dentist promptly. If a fragment has come off, keep it in milk or saline solution. In case of severe pain, bleeding or swelling, seek care the same day, if necessary through an emergency dental service.

Does a molar broken by decay always hurt?

A molar broken by decay does not always hurt: a small chip may remain painless, while a deep fracture that reaches the nerve causes sharp pain with hot, cold or chewing. The absence of pain does not mean the problem is not serious: a weakened tooth should be examined even if it does not hurt.

How can you tell whether the tooth's nerve is affected?

The nerve (pulp) of a broken molar is probably affected if you experience intense, prolonged pain, marked sensitivity to hot and cold, or see a pink or red area in the center of the fracture. Only an X-ray at the dentist's office can confirm this and determine whether root canal treatment is necessary.

Is a crown always necessary for a broken molar?

A crown is not always necessary: it is reserved for extensive fractures where a large part of the molar has been destroyed. For a small or medium-sized break, a composite or an inlay/onlay is often enough to restore the tooth. The dentist determines the most suitable solution after an examination and X-ray.

Can you keep a broken molar without treating it?

Keeping a broken molar without treating it is strongly discouraged: the opening allows bacteria to progress toward the nerve, exposing you to pain, infection, an abscess, and eventually tooth loss. Even if it is painless, a broken molar should be evaluated by a dentist and protected before it deteriorates further.

Can a broken molar be extracted and then replaced?

A molar that is too damaged to save may be extracted and then replaced with an implant or bridge. This replacement is important: a missing molar allows the neighboring teeth to shift and disrupts chewing. The dentist considers extraction only as a last resort, when the root is fractured or too severely damaged.

How can you prevent a molar from breaking again?

To prevent another broken molar, the priority is to prevent cavities through rigorous oral hygiene: brush the back molars thoroughly, use dental floss or a water flosser, and have annual checkups. In cases of bruxism, a mouthguard protects the teeth at night. Daily sonic brushing helps remove more plaque where cavities begin.

How much does it cost to repair a broken molar?

The cost of a broken molar depends on the treatment chosen: a composite filling costs a few dozen euros, a crown costs approximately €400 to €1,200, and an implant with a crown costs approximately €1,500 to €3,000. Some crowns for molars are covered by the 100% Santé scheme and are then fully reimbursed. Only a quote from your dentist, considered together with your supplementary health insurance, will show the actual out-of-pocket cost.

Can the piece of a broken molar be reattached?

Reattaching a fragment of a broken molar is sometimes possible when the piece is intact and the pulp is not affected. Keep the fragment in milk or saline solution and bring it to the dental office promptly. However, repair is most often done with composite, an inlay/onlay, or a crown, depending on the extent of the damage; the dentist decides after an examination and X-ray.

How long can you wait before seeing a dentist for a broken molar?

You should not wait more than a few days, and seek care the same day in case of severe pain, bleeding, or swelling. Even a painless broken molar should be examined promptly: the opening allows bacteria to progress toward the nerve, and the tooth becomes weaker with every bite. The earlier treatment begins, the more options remain for preserving the tooth.