Toothache: What's important to know?

Toothache is a symptom, not a disease in itself. In everyday speech, it refers to pain in the tooth, gum, or jaw, but clinically, this complaint can be caused by caries, pulpitis, apical inflammation at the root apex, abscess, tooth fracture, pericoronitis, and sometimes even non-dental causes. A recent review from 2025 emphasizes that odontogenic pain remains the most common form of orofacial pain, but it is not the only one. [1]

According to the International Classification of Diseases, 10th revision, the code K08.8, meaning "other specified disorders of the teeth and their supporting apparatus," is most often used for toothache itself, if the symptom is not fully defined. Once the cause has been established, the coding changes: for example, K02 is used for caries, K04.0 for pulpitis, K04.4 for apical periodontitis, and K04.7 for periapical abscess. This is important not only for documentation but also for proper clinical logic: first, the symptom is recorded, then the cause.

From a clinical perspective, toothache is particularly important because it often signals the progression of a process from a superficial lesion to a deeper one. The typical path is carious lesion, followed by pulp inflammation, periapical tissue involvement, and, in some cases, abscess formation. However, this path doesn't always follow a strictly textbook pattern, and therefore modern dentistry emphasizes not "guessing by sensation," but a combination of symptoms, examination, tests, and radiographic data. [2]

For the patient, the most important practical conclusion is that toothache is almost never considered permanently resolved simply by taking a pill. The American Dental Association and endodontic guidelines agree that for pulpal and periapical causes, dental intervention remains the decisive factor: tooth restoration, vital pulp therapy, root canal treatment, drainage, or tooth extraction, if indicated. Pain relief is a bridge to treatment, not a complete substitute. [3]

A separate problem is that toothache can be the first sign of a condition that extends beyond the tooth. Rapidly increasing swelling, fever, difficulty swallowing, trismus, voice changes, and neck swelling indicate not just a "bad tooth," but the risk of a deep-tissue odontogenic infection. This is why a modern article on toothache must address not only the causes of the pain but also the red flags. [4]

The table below shows how complaints and specified reasons are typically coded. [5]

Clinical situation	International Classification of Diseases, 10th revision code	What does it mean?
Toothache without an unspecified cause	K08.8	Symptom rubric before final diagnosis
Dental caries	K02	Destruction of hard dental tissues
Pulpitis	K04.0	Inflammation of the pulp
Acute apical periodontitis of pulpal origin	K04.4	Inflammation of the tissues at the root apex
Periapical abscess without and with fistula	K04.7	Purulent process at the root apex

Why does toothache occur?

The main biological source of toothache is irritation or inflammation of tissues rich in sensitive nerve endings. The dental pulp, the vascular-nerve complex within the tooth, is particularly important. When decay, a crack, an injury, or a leaky old filling approaches the pulp, an inflammatory reaction occurs, and the confined space inside the tooth makes this pain particularly intense. [6]

Modern endodontic charts from 2025 demonstrate that early forms of pain do not always indicate irreversible destruction. With hypersensitive pulp and mild pulpitis, pain is more often triggered by cold, sweets, or air, but does not last long and does not necessarily indicate an infection within the pulp. In these situations, tooth restoration and vital treatment methods are possible, and endodontic intervention is not always required. [7]

When inflammation becomes more severe, severe pulpitis develops. In such cases, pain can be spontaneous, prolonged, nocturnal, pulsating, sometimes aggravated by heat, and persisting after the stimulus ceases. Modern terminology is moving away from the overly simplified distinction between "reversible" and "irreversible" pulpitis, but the clinical meaning remains the same: the deeper and more persistent the inflammation, the higher the likelihood that the tooth will require a pulpotomy or full root canal treatment. [8]

If the pulp dies, necrosis occurs. Then, the acute pain may sometimes even temporarily subside, creating a false sense of improvement. But this is not recovery: the infection may already extend beyond the root and involve the periapical tissues, causing pain when biting, a feeling of "overgrown tooth," gingival swelling, and later, an abscess. This is why a sudden decrease in pain after a severe pulpal episode is not always a good sign. [9]

It's also important to note that not all tooth pain actually originates from the tooth. A 2025 review emphasizes that temporomandibular disorders, neuropathic pain, sinusitis, migraine, and other orofacial syndromes can mimic toothache. This is especially likely if the clinical picture doesn't match the test results, if the pain is poorly localized, or if the tooth appears clinically and radiographically normal. [10]

The table below helps us understand which mechanisms are most often behind different sensations. [11]

Mechanism	How pain is most often felt	What is usually behind this?
Dentin hypersensitivity and early pulpal irritation	A short pain from cold, sweet air	Dentin exposure, early or mild pulpitis
Severe inflammation of the pulp	Long-lasting, throbbing, nighttime pain	Severe pulpitis
Periapical tissue lesions	Pain when biting, tapping	Apical periodontitis
purulent process	Distension, swelling, soreness of the gums, sometimes the taste of pus	Periapical abscess
Non-odontogenic pain	Unclear localization, no match with tooth tests	Temporomandibular disorder, neuralgia, sinusitis and others

The main causes of toothache

The most common cause is tooth decay, which gradually destroys enamel and dentin. While the process is superficial, pain may be absent altogether. However, as the pulp is approached, reactions to cold, sweets, and mechanical stimuli appear. Patients often underestimate the situation because pain in the early stages is still intermittent. [12]

The next most common cause is pulpitis. Current endodontic charts from 2025 differentiate between mild and severe pulpitis. In mild cases, the tooth can often be saved with vital pulp therapy or restoration. In severe cases, the treatment spectrum shifts toward partial or complete pulpotomy or root canal treatment, as the inflammation is deeper and progressing. [13]

A very common cause of pain is apical periodontitis. It is characterized by pain when biting, a sensation of the tooth being "in the way" or "overgrown," and pain when tapped. The 2025 Joint Table of the American Association of Endodontists and the European Society of Endodontics clearly states that localized symptomatic apical periodontitis is an inflammation of the periapical region of pulpal origin, for which endodontic intervention is indicated. [14]

If the inflammation progresses to a purulent process, a periapical abscess develops. It may be localized or accompanied by systemic involvement. When diffuse facial swelling, fever, lymph node tenderness, and general malaise occur, the situation becomes much more serious: the 2025 joint table indicates that apical abscesses with systemic involvement require immediate endodontic intervention to alleviate symptoms or drainage, as well as antibiotics. [15]

Pericoronitis is a separate cause, especially around the eight partially erupted teeth. In this situation, the pain is localized not so much in the tooth itself as in the soft tissues above and around it. An unpleasant taste, pain when swallowing, difficulty opening the mouth, and swelling of the gums behind the last molars often occur. Although this is not a classic pulpal source, patients often describe the condition as "severe toothache."

Finally, non-odontogenic causes should always be considered. A recent review emphasizes that temporomandibular disorders, neuropathic pain, and other orofacial syndromes can masquerade as pain in a specific tooth. This is especially likely if dental tests do not confirm the source, if the pain migrates, or if it is inconsistent with the radiographic findings. [16]

The table below summarizes the main causes and clinical clues.[17]

Cause	What does the patient usually feel?	What especially helps to suspect
Caries approaching the pulp	Reaction to cold, sweet, air	Visible cavity or leaky restoration
Mild pulpitis	Short evoked pain	No lingering pain after the stimulus
Severe pulpitis	Spontaneous, nocturnal, prolonged pain	Heat may aggravate the symptom.
Symptomatic apical periodontitis	Pain when biting and tapping	The feeling of a "growing tooth"
Periapical abscess	Swelling, distension, sometimes a purulent taste	Fluctuation, swelling of the gums, general malaise
Pericoronitis	Pain behind the last tooth, difficulty opening the mouth	Partially erupted 8th tooth
Non-odontogenic pain	Vague or migrating pain	Negative dental tests, non-compliance with examination

Red Flags: When Help Is Needed Urgently

The most important red flag is rapidly increasing swelling of the face, gums, floor of the mouth, or neck. This indicates that the infection may have spread beyond the localized area and is spreading into the soft tissues. If the swelling is accompanied by fever, weakness, and general intoxication, it's no longer just a "bad tooth" but a potentially dangerous odontogenic infection. [18]

Particularly dangerous are difficulties with breathing, swallowing, or speaking, as well as swelling in the neck or around the eye. The British Health Service explicitly states that toothache combined with such swelling requires emergency care. This is due to the risk of deep neck infections and airway compromise. [19]

Ludwig's angina is considered a classic, severe form. This is a rapidly progressing phlegmon of the floor of the mouth, most often arising from an odontogenic infection of the lower molars. It is characterized by dense, bilateral swelling of the submandibular region, pain, difficulty swallowing, salivation, limited mouth opening, a "hot potato" voice, and the risk of rapid airway closure. [20]

Urgent care is also needed in cases of dental trauma. Dislocation, crown fracture with pulp exposure, suspected root fracture, and especially complete tooth dislocation require very rapid dental care. In traumatic situations, time directly impacts the chances of preserving the tooth and preventing subsequent complications. [21]

Another important sign is severe pain that persists, interferes with sleep, and is not relieved by temporary symptomatic treatment, especially if dental care is not immediately available. This situation is not always life-threatening, but it requires immediate, in-person intervention, as odontogenic infection itself does not resolve with "letting it alone" and can progress. [22]

The table below shows situations in which delaying treatment is dangerous. [23]

Red flag	Why is this dangerous?
Rapid swelling of the cheek, gums, face	The infection can spread into soft tissues.
Fever, chills, weakness against the background of toothache	Systemic infection is possible
Difficulty breathing, swallowing, or speaking	Risk of damage to deep tissues of the neck and airways
Swelling of the floor of the mouth, submandibular region, salivation	Ludwig's angina must be ruled out.
Severe trismus	A deeper infection is possible
Tooth injury, dislocation, fracture	Time affects the chance of saving a tooth.

Diagnosis and differential diagnosis

Modern dental pain diagnosis begins not with X-rays or pain relief, but with a clinical history. The nature of the pain, its duration, and its relationship with cold, hot, and sweet foods, biting, nighttime, chewing, and recent treatment are all important. The 2025 Endodontic Guidelines specifically emphasize the importance of the clinical history and comparing complaints with test results. [24]

The next step is an oral examination and localization of the offending tooth. The dentist evaluates cavities, old restorations, cracks, gum condition, tooth mobility, tenderness to percussion and palpation, and the presence of a fistula, swelling, and purulent discharge. Percussion and palpation are particularly important in periapical pathology, as they often cause the characteristic pain. [25]

Pulp testing remains key. The 2025 tables emphasize the role of thermal and electrical testing, as well as comparison with control teeth. A short, non-prolonged response more often supports hypersensitivity or mild pulpitis. Prolonged pain or lack of response with an appropriate clinical picture more often indicates severe pulpitis or necrosis. [26]

Radiographic evaluation is helpful, but does not replace clinical diagnosis. In early pulpal conditions, radiographs may not reveal significant changes at the root apex. In apical periodontitis and abscesses, periapical radiolucency is more often detected; however, its absence does not rule out early inflammation. This is why modern endodontics relies on a combination of symptoms, tests, and radiographs, rather than a single indicator. [27]

It is crucial not to overlook non-odontogenic pain. A 2025 review reminds us that temporomandibular disorders, neuropathic pain, and other orofacial causes can masquerade as pulpitis. If a tooth does not explain the intensity of the pain clinically and radiographically, if the symptom migrates, or if multiple interventions have failed to improve the picture, the diagnostic search should be expanded rather than continuing to treat a random tooth. [28]

Differential diagnosis is especially important in controversial cases. Pulpal pain is more often associated with temperature stimuli and may radiate. Periapical pain is more pronounced when biting. Pericoronitis is localized around a partially erupted tooth. Pain associated with temporomandibular disorder is more often triggered by opening the mouth and chewing, rather than by cold or sweet foods. Such clinical analysis is often more important than any single technique. [29]

The table below shows which tools really change tactics. [30]

Method	What helps to find out	Why is it important?
Collection of anamnesis	Pain pattern and triggering factors	Helps differentiate between pulpal and periapical pain
Oral examination	Caries, crack, fistula, edema, pericoronitis	Clarifies the source of pain
Percussion and palpation	Involvement of periapical tissues	Important in apical periodontitis
Thermal and electrical tests	Pulp condition	Helps to differentiate viable pulp from necrosis
X-ray	Periapical changes, depth of caries, cracks indirectly	Confirms and complements the clinic
Comparison with control teeth	Individual response rate	Reduces the risk of misinterpretation
Extended Differential Assessment	Non-odontogenic causes	Needed for atypical or persistent pain

Treatment

The main modern principle of treatment is to eliminate the cause, not just the pain. The American Dental Association's antibiotic guidelines and international endodontic guidelines agree that dental care should be the first priority for pulpal and periapical conditions, rather than indefinite symptomatic pain relief with pills. [31]

For acute dental pain, non-opioid pain relievers are considered the first-line treatment. The 2024 Guidelines for the Pharmacological Treatment of Acute Dental Pain found that non-steroidal anti-inflammatory drugs (NSAIDs), alone or in combination with acetaminophen (paracetamol), generally provide superior pain relief and a more favorable safety profile than opioids. Opioids are recommended to be reserved for limited situations when first-line medications are ineffective or contraindicated. [32]

Antibiotics are not necessary for every toothache. The American Dental Association specifically recommends against their use for most pulpal and periapical conditions without systemic involvement, instead prioritizing pulpotomy, pulpectomy, endodontic treatment, or drainage. However, if fever, malaise, diffuse swelling, lymphadenopathy, and other signs of systemic infection occur, antibiotics are indicated as part of treatment. [33]

Modern endodontics increasingly strives to preserve the tooth and, when possible, preserve the vital portion of the pulp. The 2025 Joint Tables and updated description of endodontic guidelines indicate that in some cases of mild and even severe pulpitis, vital pulp treatment methods, as well as partial or complete pulpotomy, may be considered. Root canal treatment remains very important, but is no longer the automatic, sole answer to every severe toothache. [34]

In cases of apical abscess with systemic involvement, the approach should be proactive. The 2025 Joint Table indicates the need for immediate endodontic intervention to relieve symptoms and drain active infection, as well as indications for antibiotics and analgesia. If Ludwig's angina or other deep infection develops, the priority is maintaining an airway, intravenous antibiotics, and surgical drainage when indicated. [35]

Prophylactic antibiotic therapy before dental procedures is not necessary for everyone. The American Dental Association indicates that it is only justified in a relatively small group of patients at highest risk for adverse outcomes from infective endocarditis, particularly for procedures involving gingival manipulation, periapical manipulation, or mucosal perforation. Routine prophylaxis is generally not recommended for patients with joint replacements. [36]

The table below summarizes current treatment tactics. [37]

Scenario	What is usually the basis of treatment?
Dentin hypersensitivity	Elimination of the cause, protection of dentin, restorative treatment according to indications
Mild pulpitis	Restoration, vital pulp therapy according to indications
Severe pulpitis	Partial or complete pulpotomy or root canal treatment
Pulp necrosis and apical periodontitis	Root canal treatment, in some cases tooth extraction
Localized apical abscess	Drainage and elimination of the source of infection
Apical process with systemic involvement	Urgent intervention plus antibiotics
Short-term pain relief before treatment	Nonsteroidal anti-inflammatory drugs alone or with paracetamol
Preventive antibiotics before procedures	Only for a narrow group of high-risk patients

Prevention and prognosis

The best way to prevent toothache is to avoid symptoms and prevent decay and cracks from progressing to the deepest stages. Since pain often appears when the process has already reached the pulp or the root apex, regular examinations and early restoration of defects reduce the risk of acute pain and more complex treatment. [38]

Behavioral prevention of complications is also very important. If pain has already occurred, one should not take antibiotics without medical supervision, repeatedly apply harsh topical treatments, or postpone dental treatment just because a pill temporarily helped. The American Dental Association emphasizes that antibiotics are not a substitute for addressing the underlying cause, and unnecessary use increases the risk of side effects and bacterial resistance. [39]

The prognosis for most forms of toothache is good if treatment is started promptly. In cases of mild pulpal damage and early caries, preservative and minimally invasive approaches are often sufficient. Delayed treatment reduces the chances of preserving vital pulp, and treatment becomes more complex, time-consuming, and expensive. [40]

The most dangerous aspect of a spreading infection is delayed diagnosis. Ludwig's angina and other deep neck infections do not develop in the majority of patients, but they pose the greatest risk to life. Modern reviews emphasize that outcome is determined by the speed of recognition, airway management, intravenous antibiotic therapy, and surgical drainage, if necessary. [41]

A separate component of prognosis is correct differential diagnosis. When the doctor and patient understand that not all pain originates from the tooth, the risk of unnecessary treatment of the wrong tooth and repeated unsuccessful interventions is reduced. Therefore, a good prognosis depends not only on the treatment technique but also on the accuracy of the diagnosis from the very beginning. [42]

The table below summarizes what actually improves the outcome. [43]

What improves the prognosis	Why is this important?
Early treatment for pain from cold, sweets and chewing	Allows intervention before deep pulp damage occurs
Avoid self-medication with antibiotics	Reduces the risk of treatment failure and resistance
Rapid drainage and elimination of the source of infection	Prevents the spread of the process
Emergency care for neck swelling and difficulty swallowing	Reduces the risk of respiratory complications
Accurate differential diagnosis	Helps avoid treating the wrong tooth and not miss non-odontogenic pain
Regular dental check-ups	Reduces the risk of acute episodes and tooth loss

Frequently asked questions

Does toothache always indicate tooth decay?
No. While tooth decay remains the most common cause, pain can be associated with pulpitis, apical periodontitis, abscesses, cracked teeth, pericoronitis, and even non-dental causes, such as temporomandibular disorder or neuropathic pain. [44]

If a tooth hurts only from cold, is it a "nerve"?
Not necessarily. According to current tables from 2025, short-term pain from cold or sweets without a long-term residual pain response more often corresponds to hypersensitive pulp or mild pulpitis, and not necessarily to deep, irreversible pathology. [45]

Why does pain sometimes subside, only to return with swelling?
This happens when the pulp dies and the pain from within the tooth temporarily subsides, but the infection has already begun to spread to the tissue at the root apex. In this scenario, "getting better" doesn't mean recovery. [46]

Do antibiotics help with pulpitis?
For most isolated pulpal and localized periapical conditions without systemic involvement, antibiotics are not recommended. The American Dental Association recommends performing dental intervention and using pain relief as indicated. [47]

What is currently considered the best pain relief for acute toothache?
According to the 2024 guidelines, non-opioid agents, primarily non-steroidal anti-inflammatory drugs (NSAIDs) alone or in combination with paracetamol, are considered first-line treatment. Opioids have a more limited role and are recommended for limited use. [48]

When should you seek emergency care instead of just waiting for a dentist appointment?
Immediate care is needed for neck swelling, difficulty breathing, swallowing, or speaking, rapidly increasing facial swelling, as well as a high fever and increasing overall deterioration. [49]

Do people with artificial joints need antibiotics before dental treatment?
Generally, no. The American Dental Association advises that routine prophylaxis before dental procedures is not recommended for patients with artificial joints; certain exceptions require approval from the treating physician. [50]

Who might actually need antibiotic prophylaxis before a dental procedure?
Only a small group of patients at highest risk for an adverse outcome from infective endocarditis, such as those with certain valvular and congenital heart conditions. The decision is made based on current cardiology and dental guidelines, not automatically as a "safety net." [51]

Key points from experts

Alonso Carrasco-Labra, DDS, MS, PhD, is an associate professor in the Department of Preventive and Restorative Dentistry and the Center for Integrative Global Oral Health at the University of Pennsylvania School of Dentistry and one of the lead authors of the 2024 guideline for the management of acute dental pain.
Key message: For acute dental pain and post-dental procedures, non-opioids, primarily non-steroidal anti-inflammatory drugs (NSAIDs) alone or with acetaminophen, should be considered first-line treatment, with opioids reserved for limited situations. [52]

Peter B. Lockhart, DDS, is a clinical professor in the Department of Oral Medicine at Atrium Health Carolinas Medical Center and the lead author of the American Dental Association's guideline on antibiotics for dental pain and swelling.
Key message: Antibiotics should not be prescribed for most patients with pulpal and localized periapical pain without systemic involvement; drainage, endodontic treatment, removal of the source of infection, and rational pain management remain the mainstay of care. [53]

Henry F. Duncan, Professor and Consultant in Endodontics at the University Dental Hospital Dublin and Trinity College Dublin, is one of the key authors of the European Endodontic Clinical Guidelines.
His key thesis is that modern endodontics should not simply “kill the nerve,” but rather accurately diagnose the extent of pulp damage and, whenever possible, utilize vital pulp therapy and tooth-preserving strategies alongside traditional root canal treatment. [54]

A practical general conclusion from expert guidelines:
For toothache, the best outcome is achieved not by the strongest analgesic or the broadest antibiotic, but by an accurate diagnosis, timely intervention, and early recognition of the red flags of a widespread infection. [55]