Tooth sensitivity – why it happens and what it is telling you
Tooth sensitivity is one of the most common issues that brings patients to the dentist. It is most often described as a brief, sharp pain that occurs when consuming cold, hot, sweet, or acidic foods and drinks. The pain usually lasts a few seconds, but it can be very unpleasant and affect everyday quality of life.
It is important to emphasise that tooth sensitivity is not a diagnosis in itself, but a symptom. It indicates that dentine has become exposed — the inner layer of the tooth located beneath the enamel and the gum line. When dentine is exposed, stimuli from the mouth reach nerve endings more easily, causing the characteristic, stabbing pain.
Many patients attribute sensitivity to “weak enamel” or to a “chilled tooth”, but the real causes are often more complex. Most commonly, the problem is driven by a combination of mechanical, chemical, and inflammatory factors that gradually damage the tooth’s protective structures.
Sensitivity can appear suddenly or develop gradually. In some people it is seasonal, for example after consuming cold drinks in summer, while in others it is present throughout the year. This is exactly why understanding the mechanism behind sensitivity matters, so it can be treated properly.
What happens inside the tooth when sensitivity occurs?
To understand tooth sensitivity, it helps to briefly explain tooth structure. The outer layer of the tooth is enamel — the hardest structure in the human body. Beneath enamel lies dentine, which is softer and permeated by tiny tubules. These dentinal tubules are connected to the dental pulp, where the nerves and blood vessels are located.
When enamel is intact and the gums attach properly around the neck of the tooth, dentine is protected. However, if enamel wears down, the gums recede, or the tooth surface is chemically damaged, dentine can become exposed.
Exposed dentinal tubules react to temperature and chemical stimuli. Cold, heat, or acids cause fluid movement within the tubules, which stimulates the nerve endings in the pulp. This mechanism explains the sudden and short-lived pain that is typical of tooth sensitivity.
It is important to distinguish sensitivity from persistent, throbbing pain, which can indicate pulp inflammation or a more serious issue such as deep decay. With sensitivity, pain stops as soon as the stimulus is removed, whereas in inflammatory conditions pain may persist even without an external trigger.
The most common causes of tooth sensitivity
Tooth sensitivity almost never occurs without a reason. In most cases, it is a gradual process in which enamel becomes damaged or the gums recede, leaving dentine unprotected. Understanding the cause is crucial so treatment can target the source of the problem, not just reduce symptoms.
Enamel wear (erosion and abrasion)
Enamel is extremely strong, but it is not indestructible. Long-term exposure to acids from food and drink — such as fizzy drinks, citrus fruits, or energy drinks — can lead to chemical dissolution of enamel, a process known as dental erosion. As enamel thins, dentine becomes closer to the surface and sensitivity increases.
On the other hand, mechanical wear of enamel, known as abrasion, is often the result of incorrect brushing technique, using hard-bristled toothbrushes, or toothpastes with a high abrasive effect. Horizontal movements combined with strong pressure damage the tooth surface over time, especially at the neck of the tooth, where enamel is naturally thinner.
The combination of chemical erosion and mechanical abrasion is particularly risky. For example, brushing immediately after consuming acidic drinks can further accelerate the wear of already softened enamel.
Gum recession
One of the most common causes of sensitivity is gum recession (gingival recession). When the gums recede, the tooth root becomes exposed, and the root does not have a protective enamel layer. The root is covered by cementum, which is significantly softer and more vulnerable to damage.
Exposed roots are particularly sensitive to cold and touch. Patients often notice sharp pain when drinking cold water or during professional tooth cleaning. In addition, these areas are more prone to plaque build-up and the development of root decay.
Gum recession can be a consequence of incorrect hygiene, gum inflammation, anatomical characteristics, or excessive loading of the teeth.
Bruxism and excessive loading
Teeth grinding, especially at night, causes micro-damage to enamel and additional stress on tooth structures. Over time, enamel thins, small cracks develop, and sensitivity increases.
Bruxism can also contribute to gum recession, which further increases dentine exposure. Many patients are not aware that they grind their teeth until symptoms appear, such as morning jaw soreness, headaches, or tooth sensitivity.
Tooth decay and cracks
Tooth sensitivity can also be an early sign of tooth decay. In early stages, decay affects enamel without pain, but when it reaches dentine, sensitivity to sweet and cold stimuli can occur.
Small cracks (microfractures) can also cause pain when chewing or when consuming cold drinks. These cracks are often not visible to the naked eye, but they allow stimuli to penetrate towards the interior of the tooth.
After dental procedures
Temporary sensitivity can also occur after certain dental procedures, such as professional cleaning, whitening, or replacing fillings. In most cases, this is a short-lived reaction that decreases within a few days.
If sensitivity lasts longer or becomes more intense, a review appointment is necessary to rule out other causes.
How to tell tooth sensitivity apart from more serious conditions
Although tooth sensitivity is common and in most cases benign, it is important to know when it is simple dentine hypersensitivity and when it may indicate a more serious problem such as deep decay, pulp inflammation, or a tooth crack.
Classic dentine hypersensitivity is characterised by a short, sharp pain lasting a few seconds and occurring only in response to a stimulus — for example cold, toothbrush contact, or sweet foods. Once the stimulus is removed, the pain stops. There are no spontaneous pains and no night-time episodes without a clear trigger.
By contrast, pain that lasts longer than a few seconds, throbs, occurs spontaneously, or worsens at night may indicate pulp inflammation. Such pain often requires urgent dental intervention. Likewise, pain when biting or chewing can point to a cracked tooth or an issue with an existing filling.
That is why it is important not to diagnose yourself. Even when sensitivity seems harmless, the underlying cause can vary, and treatment depends precisely on that distinction.
Diagnosing tooth sensitivity
Diagnosis is made through a clinical examination. The dentist assesses enamel condition, the presence of gum recession, decay, fillings, and potential cracks. Particular attention is paid to the neck of the tooth, where sensitivity most commonly occurs.
In some cases, X-rays are used to exclude deeper pathological processes. Cold sensitivity tests help assess tooth vitality and differentiate dentine hypersensitivity from pulpitis.
A key part of diagnosis is discussion with the patient. Information about brushing habits, diet, consumption of acidic drinks, bruxism, or recent whitening can be crucial for understanding the cause.
Treating tooth sensitivity
Treatment depends on the cause and the severity of symptoms. In milder cases, the focus is on conservative methods.
Adjusting oral hygiene
The first step is often correcting brushing technique. A soft-bristled toothbrush and gentle circular movements without excessive pressure are recommended. This prevents further mechanical damage to enamel and the gums.
Toothpaste for sensitive teeth contains ingredients that block dentinal tubules or reduce nerve signal transmission. With regular use over several weeks, symptoms can be significantly reduced.
Professional treatments in the dental surgery
If home measures are not sufficient, desensitising agents can be applied in the surgery to create a protective layer on the dentine surface. In some cases, fluoride varnish is used to strengthen enamel.
If there are pronounced defects at the neck of the tooth, a composite filling can be placed to cover exposed dentine and reduce sensitivity.
If the cause is decay or a crack, the underlying problem must be treated. In cases of pulp inflammation, endodontic treatment may be indicated.
Can tooth sensitivity be eliminated permanently?
In many cases, symptoms can be controlled successfully and reduced significantly. However, a permanent solution depends on removing the cause. If harmful habits are not changed or inflammation is not treated, sensitivity can return.
Prevention plays a central role. This includes proper oral hygiene, moderate consumption of acidic foods, avoiding aggressive brushing, and regular dental check-ups.
When should you see a dentist?
If sensitivity lasts longer than a few weeks, becomes more intense, occurs spontaneously, or is accompanied by discomfort when chewing, you should book an examination. Early diagnosis helps prevent more serious complications and allows simpler treatment.
Tooth sensitivity is not something to ignore. Although it is often not dangerous, it is a signal that the tooth’s protective layer has been compromised. Timely action and individually tailored therapy help preserve tooth health and long-term oral stability.
Specific risk groups and tooth sensitivity
Although tooth sensitivity can occur in anyone, certain patient groups have a higher risk due to specific physiological or treatment-related circumstances. In such cases, prevention and treatment need to be individualised and adapted to the current condition of the mouth.
Pregnant women
During pregnancy, hormonal changes affect the gums and the oral mucosa. Higher progesterone levels can increase gingival reactivity, leading to more frequent inflammation, bleeding, and resulting sensitivity.
In addition, nausea and vomiting in the first trimester expose teeth to stomach acid, which can weaken enamel. This makes dentine more sensitive to external stimuli. During this period, it is particularly important to avoid brushing immediately after vomiting; instead, wait at least 30 minutes and rinse the mouth with water or a mild bicarbonate solution to neutralise the acid.
Regular dental check-ups during pregnancy allow timely recognition of changes and prevent further damage.
People with orthodontic appliances
Fixed braces make oral hygiene more difficult and increase plaque retention around brackets and wires. If hygiene is not consistent and correct, enamel demineralisation and hypersensitivity can develop.
During orthodontic therapy, teeth move through bone, which in certain phases can cause temporary sensitivity to pressure and temperature. Although this discomfort is expected and usually short-lived, it is important to distinguish treatment-related sensitivity from pathological changes.
Patients with braces are advised to use specialised toothbrushes, interdental cleaning aids, and fluoride-containing toothpastes to protect enamel.
Patients after tooth whitening
Tooth whitening is one of the most common aesthetic procedures, and sensitivity is its most frequent side effect. Active ingredients in whitening products temporarily increase enamel permeability, allowing stimuli to penetrate more deeply towards dentine.
Sensitivity most often appears during treatment or immediately afterwards and is generally temporary. However, in people with existing gum recession or thinned enamel, symptoms can be more pronounced.
In such cases, desensitising toothpastes are recommended before and after whitening, along with an individual assessment of whether the procedure is appropriate.
Long-term control and maintaining dental health
Tooth sensitivity is not just a minor, temporary discomfort — it is a clear indicator that the tooth’s natural protection has been disrupted. Whether the cause is worn enamel, gum recession, bruxism, or the effects of dental procedures, each cause requires precise diagnosis and an individually tailored therapeutic approach.
Early recognition of symptoms, properly adapted oral hygiene, and regular dental check-ups are key to preventing further damage. In a large number of cases, timely intervention allows the condition to be stabilised and symptoms reduced without the need for more complex procedures.
A systematic, professionally guided approach is the only way to ensure long-term stability, function, and preservation of dental health.