Dra. Cléo Salustiano In this article
SummaryMain causes of back tooth painWhat to do at home and when to seek careFAQRead nextBack Tooth Pain: Causes of Molar Pain and What to Do
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Back tooth pain is usually caused by decay, a problem filling, a cracked tooth, an erupting or inflamed wisdom tooth, food trapped between teeth, a root infection, bruxism or, in upper molars, sinusitis. The type of pain is a guide: brief sensitivity to cold suggests decay, sharp pain on biting suggests a crack and throbbing night-time pain suggests nerve inflammation. At home, flossing, warm-water rinses and avoiding chewing on the painful side help, and pain relievers only with professional advice. Spreading swelling, fever or difficulty swallowing or breathing require the emergency room. In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients every day, from 8 a.m. to 10 p.m.
A painful back tooth usually has a cause the dentist can identify during the exam: the most common are tooth decay, a problem filling, a cracked tooth, an erupting or inflamed wisdom tooth, food trapped between teeth with gum inflammation and, in some cases, an infection at the root. Molars do most of the chewing work and are the hardest teeth to clean, so they account for a large share of toothaches. Mild, brief pain with cold can wait a few days for an appointment; strong, throbbing pain that wakes you at night or comes with swelling needs care as soon as possible.
In clinical practice, the type of pain is a useful guide. Pain when biting on a specific spot suggests a crack or a high filling. Pain with cold or sweets that fades quickly is usually linked to decay or sensitivity. Constant, pulsing pain points to inflammation of the nerve. Pain in the last tooth with a swollen gum suggests a wisdom tooth. And pain in several upper teeth at once that gets worse when you bend forward may even be related to sinusitis.
Dr. Cléo Salustiano (CRO-SP 170844), a dentist in Mooca, explains the main causes of back tooth pain, how each one usually feels, what to do at home while you wait for an appointment and which signs mean it is urgent.
This article comes from Dr. Cléo Salustiano's dental office in Mooca, São Paulo (care in English, Portuguese and Spanish). See the general dentistry page to learn how the treatment is done here and book your assessment.
Main causes of back tooth pain
Decay and fillings: molars have deep grooves on the chewing surface and sit tightly against each other, which makes it easy for plaque to build up and for decay to start, including between the teeth, where you cannot see it in the mirror. Early decay causes sensitivity to cold and sweets. When it progresses, it can reach the pulp (the "nerve") and cause spontaneous pain. Old fillings with leakage and recent fillings that ended up too high are also frequent causes of pain when chewing.
Cracked tooth: because molars take most of the biting force, they are the teeth that crack most often, especially in people who grind or clench or who have large fillings. The typical sign is a sharp, brief pain when biting something, sometimes when releasing the bite, in a spot that is not always easy to pinpoint. Read more in cracked tooth: symptoms and treatment.
Wisdom tooth: when the pain is in the very last tooth, the wisdom tooth is a prime suspect. As it erupts, it may stay partly covered by gum, which traps food and becomes inflamed, a condition called pericoronitis. A poorly positioned wisdom tooth can also push against or encourage decay in the molar in front of it. The article when to remove wisdom teeth explains when removal is indicated.
Other causes: food trapped between molars, which inflames the gum and creates a feeling of pressure; gum inflammation or periodontal pockets; an infection at the root tip or an abscess, which can cause strong pain, swelling and a tooth that feels "taller"; bruxism and jaw joint problems, which cause diffuse pain in the back teeth, especially on waking; and sinusitis, which can cause pain in several upper molars at once because their roots sit close to the maxillary sinus. To tell them apart, the dentist examines the area, tests the response to cold and tapping and, when needed, requests an X-ray.
| What the pain is like | Possible cause | What to do |
|---|---|---|
| Brief sensitivity to cold or sweets | Early decay, wear or gum recession | Book an assessment |
| Sharp pain when biting or releasing the bite | Cracked tooth or high filling | Assessment; avoid chewing on that side |
| Pressure between two teeth after eating | Trapped food and inflamed gum | Floss gently; get checked if it persists |
| Pain in the last tooth with a swollen gum | Erupting wisdom tooth or pericoronitis | Assessment within a few days |
| Constant, throbbing pain that wakes you at night | Nerve inflammation or infection | Care as soon as possible |
| Pain in several upper teeth with a blocked nose | Possible sinusitis | See a dentist and, if indicated, a doctor |
| Spreading swelling, fever or difficulty swallowing | Advanced infection | Emergency room immediately |
What to do at home and when to seek care
While you wait for an appointment, a few steps help: floss gently between the molars, because sometimes the pain comes from trapped food; rinse with warm water; avoid chewing on the painful side; avoid very cold, hot, hard or sugary foods; and keep brushing, even if the area is sensitive. A cold compress on the outside of the face, wrapped in a cloth and for a few minutes, may ease swelling. Pain relievers should only be used as directed by a doctor, dentist or pharmacist and the package leaflet.
Avoid home remedies that can make things worse: do not place an aspirin tablet or other medication on the gum, as it can burn the tissue; do not use alcohol, spirits or cleaning products in your mouth; do not put ice directly on the tooth; and do not try to pierce or squeeze a swollen gum. These measures do not treat the cause and can delay diagnosis. If strong pain suddenly disappears after several days, that does not mean the problem is solved: sometimes the nerve has stopped responding and the infection may continue.
Seek care as soon as possible if the pain is strong, throbbing, wakes you at night, lasts more than a day or two, or comes with swelling of the gum or face, pus or a bad taste. The article tooth abscess: what to do describes the signs of infection. Swelling that spreads across the face or neck, fever, or difficulty opening your mouth, swallowing or breathing require going to the emergency room immediately. Jaw pain together with chest pain or tightness, shortness of breath or a cold sweat also calls for the emergency room, because it may not be dental.
This content is for information only and does not replace an exam. Consult a dentist to find out what is causing your back tooth pain: many causes have simple treatment when assessed early, such as a bite adjustment, a filling or a cleaning. In Mooca, Dr. Cléo Salustiano sees patients every day, from 8 a.m. to 10 p.m., including Sundays and holidays, for general dentistry and dental emergencies in Mooca.
Why does my back tooth hurt?
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The most common causes are decay, an old or high filling, a cracked tooth, an erupting wisdom tooth, trapped food and a root infection. Bruxism and sinusitis can also cause molar pain. Only a clinical exam, sometimes with an X-ray, confirms the cause.
Is pain in the last tooth always a wisdom tooth?
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Often it is, especially in young adults and when the gum behind the last molar is swollen or sore. But not always: the second molar can also have decay or a crack. The dentist examines you and, when needed, requests an X-ray to see the position of the wisdom tooth.
Why does my molar hurt when I chew?
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Pain when chewing is usually linked to a high filling, a cracked tooth, decay between teeth, trapped food or inflammation at the root tip. If the pain is a sharp jolt on one specific spot when biting, a crack is an important suspect. Avoid chewing on that side and book an assessment.
Can upper back tooth pain be sinusitis?
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Yes. The roots of the upper molars sit close to the maxillary sinus, and sinusitis can cause pain in several teeth at once that gets worse when you bend forward and comes with a blocked nose. Since a dental infection can feel similar, it is worth seeing a dentist to rule out a dental cause.
How can I relieve back tooth pain at home?
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Floss gently, rinse with warm water, avoid chewing on the painful side and avoid very cold, hot or hard foods. Pain relievers only as directed by a doctor, dentist or pharmacist and the package leaflet. Do not put aspirin on the gum or use alcohol or ice directly on the tooth.
When is molar pain an emergency?
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Seek care as soon as possible if the pain is strong, throbbing, wakes you at night or comes with swelling, pus or a bad taste. Spreading swelling, fever, or difficulty swallowing, opening your mouth or breathing require the emergency room immediately, as does jaw pain with chest pain or shortness of breath.
Where can I have back tooth pain checked in Mooca?
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In Mooca, Dr. Cléo Salustiano (CRO-SP 170844) sees patients at Rua Hipódromo, 1141, near Bresser-Mooca station, Monday to Sunday, from 8 a.m. to 10 p.m., including holidays. Appointments via WhatsApp (11) 97409-7834, in Portuguese, English or Spanish.
