What Is Tooth Sensitivity?
Tooth sensitivity — sometimes referred to as dentine hypersensitivity — occurs when the underlying layer of the tooth, called dentine, becomes exposed to external stimuli. Dentine contains thousands of microscopic channels (tubules) that lead to the tooth's nerve. When these tubules are no longer shielded by enamel or gum tissue, temperature changes, sweet foods, and acidic substances can stimulate the nerve and produce a sharp, short-lived pain.
The outer enamel of the tooth crown and the gum tissue covering the root normally act as protective barriers. Enamel is the hardest substance in the body, but it can be gradually worn down by acidic erosion, abrasive brushing, or general wear over time. Similarly, gum tissue can recede due to periodontal disease, aggressive brushing, or natural ageing, exposing root surfaces that lack enamel protection.
When either of these barriers is compromised, the dentine beneath becomes vulnerable. Hot drinks, cold water, ice cream, or even breathing in cold air can trigger discomfort that ranges from a mild twinge to a sharp, sudden pain. The sensation typically subsides within seconds once the stimulus is removed, but its presence often indicates that the tooth's defences have been weakened in some way.
Common Causes of Tooth Sensitivity
Sensitivity can develop for a range of reasons, and more than one factor may be involved. The following are among the most commonly identified causes, though only a dentist can confirm the specific reason through clinical examination.
Enamel Wear from Brushing Technique
Brushing with excessive pressure or using a hard-bristled toothbrush can gradually wear down enamel, particularly along the gum line, exposing the more sensitive dentine beneath.
Gum Recession
When gum tissue recedes, the root surface of the tooth becomes exposed. Unlike the crown, the root is not covered by enamel and is more susceptible to temperature sensitivity.
Tooth Decay
Decay that extends through the enamel into the dentine can cause sensitivity to temperature, sweetness, and pressure. Early decay may be painless, but progression often produces noticeable discomfort.
Cracked or Fractured Teeth
A crack in a tooth can allow temperature changes to reach the nerve more directly, causing sharp, intermittent sensitivity that may be difficult to pinpoint.
Recently Placed Fillings
It is not uncommon to experience temporary sensitivity after a new filling. This usually resolves within a few weeks, but persistent sensitivity should be reviewed by your dentist.
Teeth Grinding (Bruxism)
Habitual grinding or clenching wears down tooth enamel over time, reducing the protective barrier and increasing sensitivity to hot, cold, and acidic substances.
Symptoms Associated with Sensitive Teeth
The experience of tooth sensitivity varies from person to person. Some individuals notice only occasional, mild discomfort, while others experience sharp pain that affects daily eating and drinking. Common presentations include:
Sharp Pain from Hot or Cold Foods
A brief, sharp discomfort when consuming hot drinks, cold water, or ice cream — one of the most commonly reported sensitivity symptoms.
Brief Discomfort That Fades Quickly
Sensitivity that lasts only a few seconds after the trigger is removed is typical of dentine hypersensitivity, though the pattern should still be monitored.
Sensitivity to Sweet or Acidic Foods
Sugary or acidic foods and beverages can stimulate exposed dentine tubules in a similar way to temperature changes, producing a fleeting sting or ache.
Localised Sensitivity in One Tooth
When sensitivity is confined to a single tooth, it often points to a specific issue such as localised decay, a crack, or recession around that particular tooth.
Discomfort When Breathing in Cold Air
In some cases, simply breathing in cold air through the mouth can trigger a sharp twinge — a sign that exposed dentine or root surfaces are responding to temperature changes.
Symptom intensity and frequency can vary. Not all of the above will be present in every case of sensitivity.
When Tooth Sensitivity Needs Professional Assessment
Mild, occasional sensitivity is common and may respond to changes in oral care habits. However, professional assessment is advisable if:
- Sensitivity is persistent or gradually worsening over time
- Discomfort affects your ability to eat or drink comfortably
- There is visible damage, swelling, or discolouration around a sensitive tooth
- Sensitivity is confined to a single tooth, which may suggest a localised issue
- The pain lingers for more than a few seconds after the trigger is removed
These patterns may indicate an underlying cause — such as decay, a crack, or advancing gum recession — that benefits from professional identification and management. Early assessment often allows for more conservative treatment approaches.
How Dentists Assess Tooth Sensitivity
Understanding the cause of sensitivity requires a structured clinical process. Your dentist may use several of the following approaches:
Clinical Examination
A thorough visual and tactile inspection of the teeth, gum tissue, and any existing restorations to identify areas of wear, recession, or damage.
Enamel and Gum Health Assessment
Evaluation of enamel thickness and gum tissue position to determine whether erosion or recession is contributing to sensitivity.
Checking for Decay or Cracks
Careful examination for signs of decay, fractures, or deteriorating restorations that may be allowing temperature stimuli to reach the nerve.
Dental Imaging
X-rays or other imaging where clinically indicated to reveal hidden decay, bone changes, or structural issues not visible during clinical examination.
Bite and Occlusal Analysis
Assessment of how the teeth meet during biting and chewing to identify grinding patterns, wear facets, or uneven pressure distribution.
Professional Management Options
Management of tooth sensitivity depends entirely on the underlying cause identified during assessment. Your dentist will discuss the most appropriate options based on the clinical findings. Possible approaches may include:
Desensitising Treatment Plans
Professional application of desensitising agents to exposed dentine surfaces can help reduce the transmission of stimuli to the tooth nerve.
Fluoride Applications
Concentrated fluoride varnish applied by your dentist strengthens enamel and can help reduce sensitivity over time with regular application.
Restoration of Decayed Areas
Where decay is identified as the cause, a filling or other appropriate restoration can seal the tooth and eliminate the pathway for temperature stimuli.
Gum Recession Management
Depending on the extent of recession, management may range from improved brushing technique and monitoring to gum grafting procedures in more advanced cases.
Protective Restorations
A dental crown or bonding may be recommended for teeth with significant enamel loss or cracks, providing a physical barrier against sensitivity triggers.
Bite Assessment and Grinding Management
Where bruxism is a contributing factor, a custom-made bite guard can help protect enamel from further wear and reduce ongoing sensitivity.
Treatment outcomes depend on individual circumstances. Your dentist will explain what can reasonably be expected based on the specific diagnosis.
Professional Assessment for Sensitive Teeth
Persistent tooth sensitivity should be evaluated to identify underlying causes and develop an appropriate management plan. Understanding the reason for your sensitivity is the first step toward effective, lasting care.
Depending on the findings, your dentist may recommend general dental care, treatment for gum health and periodontal concerns, a protective dental crown for structurally compromised teeth, or an emergency dental assessment if symptoms are severe.
Assessment for tooth sensitivity is available at our London clinics. You can attend our South Kensington dental clinic or our City of London clinic near St Paul's for a professional dental review.
Can Tooth Sensitivity Go Away on Its Own?
Mild sensitivity may improve with changes in oral care — for example, switching to a soft-bristled toothbrush, adopting a gentler brushing technique, or using a toothpaste formulated for sensitive teeth. In these cases, the dentine tubules can become partially blocked over time, reducing the transmission of stimuli to the nerve.
However, persistent or worsening symptoms often indicate an underlying issue that is unlikely to resolve without professional attention. Decay will continue to progress, gum recession typically does not reverse on its own, and cracks in teeth can extend further under daily biting forces.
Professional assessment ensures that the correct cause is identified and that any necessary treatment is provided before the condition advances. If you have noticed a change in your sensitivity, it is advisable to mention this at your next dental appointment.
Reducing the Risk of Tooth Sensitivity
While not every cause of sensitivity can be prevented, the following habits can help protect your enamel and gum health:
- Use a soft-bristled toothbrush and gentle, circular brushing motions to minimise enamel wear
- Limit consumption of highly acidic foods and drinks such as citrus fruits, fizzy drinks, and wine
- Avoid brushing immediately after consuming acidic foods — wait at least 30 minutes
- Discuss teeth grinding with your dentist if you wake with jaw tension or notice worn tooth surfaces
- Attend regular dental check-ups so early signs of enamel wear, decay, or recession can be identified
- Consider using a toothpaste formulated for sensitive teeth as part of your daily oral care routine
