Sensitive Teeth
A brief sharp sensation when eating, drinking, or breathing cold air is one of the most common dental complaints. Some patients notice it when drinking cold water, eating ice cream, biting into something sweet, or simply breathing cold air outside. For most people it is manageable. For some it is a sign that something needs attention. Understanding the cause makes all the difference.
What causes sensitive teeth?
Tooth sensitivity occurs when the dentine layer of the tooth is exposed or when the nerve inside the tooth is stimulated more easily than normal. Dentine contains thousands of tiny tubules that connect to the nerve. When these tubules are exposed, temperature, pressure, or acidic foods can trigger a sharp sensation. Several different conditions can cause this.
Exposed dentine from enamel wear
Enamel is the hard outer layer that protects the dentine. When enamel wears down from acidic foods and drinks, aggressive brushing, or teeth grinding, the dentine underneath becomes exposed. Cold, sweet, or acidic stimuli can then travel through the dentinal tubules and trigger sensitivity. This is the most common cause of generalised tooth sensitivity.
Gum recession
When the gum pulls away from the tooth, the root surface becomes exposed. Root dentine is not protected by enamel and is significantly more sensitive than the crown of the tooth. Gum recession can result from aggressive brushing, gum disease, or natural changes over time. Sensitivity in these cases is often localised to specific teeth rather than generalised.
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Notching at the gumline from clenching may also be contributing. See our tooth abrasion page for more.
Cracked tooth
A cracked tooth can allow stimuli to reach the nerve more directly than through intact tooth structure. Sensitivity from a crack is often sharp and localised to a specific tooth, and may be triggered by cold or sweet foods. It may also present as brief pain when biting or releasing pressure.
Tooth grinding and clenching
Grinding and clenching places significant wear on the enamel surface over time. Patients who grind at night often notice generalised sensitivity, particularly on the biting surfaces of teeth, and may find sensitivity is worse in the morning. The enamel in these areas becomes progressively thinner, exposing more dentine. A nightguard can help protect the teeth from further wear.
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See our teeth grinding page for more on how grinding affects teeth over time.
Tooth decay
Decay that has progressed through the enamel and into the dentine can cause sensitivity to sweet foods and cold. As decay deepens toward the pulp, sensitivity tends to become more pronounced and may eventually present as spontaneous pain rather than triggered sensitivity.
Whitening treatment
Sensitivity during or after teeth whitening is common and usually temporary. The whitening agent can increase the permeability of the dentinal tubules temporarily, making the tooth more responsive to temperature during the treatment period. This typically settles once whitening is completed. Read more on our teeth whitening sensitivity page.
Recent dental treatment
Sensitivity after a new filling, crown, or other restoration is common as the tooth adjusts. This often settles within a few days to a few weeks. If sensitivity worsens or does not improve, assessment is recommended.
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If your filling or crown has broken or feels different, see our broken filling or crown page.
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If you have older fillings you are unsure about, see our replace old fillings page.
When is tooth sensitivity a sign of something more serious?
Most tooth sensitivity is reversible and manageable. But some presentations suggest that the nerve inside the tooth is under more significant stress and needs assessment rather than monitoring.
Sensitivity that lingers after the trigger is removed
Brief sensitivity that disappears immediately when the cold or sweet stimulus is removed is usually a sign of dentine exposure. If sensitivity lingers for 30 seconds or more after the trigger is gone, this suggests the pulp may be inflamed. Lingering sensitivity after cold is one of the signs associated with irreversible pulpitis, which requires root canal treatment or extraction.
Sensitivity that is getting progressively worse
Sensitivity that was mild and occasional but is becoming more frequent or more intense is a sign that the underlying cause is progressing. This warrants assessment rather than waiting to see if it improves on its own.
Sensitivity accompanied by pain when biting
If sensitivity is occurring alongside pain when biting or chewing, this may suggest a cracked tooth or periapical involvement rather than simple dentine exposure. Assessment helps identify which is contributing.
Spontaneous pain without a trigger
If a tooth is aching on its own without any cold, heat, or pressure trigger, this is no longer simple sensitivity. Spontaneous pain is a sign of significant pulp involvement and needs prompt assessment. See our sudden severe tooth pain page if this applies to you.
What happens at a dental assessment for tooth sensitivity?
The assessment focuses on identifying which teeth are affected, what is triggering the sensitivity, and what is causing it. This guides whether preventive care, a restoration, or further investigation is the appropriate next step.
Clinical examination
The dentist examines the affected teeth for signs of enamel wear, gum recession, cracks, decay, or existing restorations that may be contributing. Gum health is assessed at the same time, particularly if recession is visible.
Sensitivity testing
Cold testing is used to assess how the tooth responds and whether the response is brief or lingering. This helps distinguish between dentine hypersensitivity and pulp involvement. The pattern of response guides the diagnosis.
X-rays
X-rays are taken to check for decay, periapical changes, and bone levels around the roots. This provides information that cannot be seen during a clinical examination alone.
Treatment options
Depending on the findings, options may include desensitising treatments, fluoride application, a restoration to seal exposed dentine, a nightguard for grinding, periodontal treatment for gum recession, or further investigation if pulp involvement is suspected. The appropriate approach is discussed before anything is decided.
Tooth sensitivity assessment at Penn Pacific Dental Center
Dr. Chrissie Lam
Tooth sensitivity assessments at Penn Pacific Dental Center are carried out by Dr. Chrissie Lam. She sees patients for a broad range of preventive and general dental care, including sensitivity assessment, scaling and polishing, teeth whitening, and restorative treatments.
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Dr. Chrissie Lam trained at the University of the Pacific, Arthur A. Dugoni School of Dentistry in San Francisco and holds an undergraduate degree from UC Berkeley. She has been based in Singapore since 2013.
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Common questions about tooth sensitivity
Can sensitive teeth be treated?
Yes, depending on the cause. Exposed dentine from enamel wear or gum recession can often be managed with desensitising treatments, fluoride application, or a restoration to seal the exposed surface. If a crack or pulp involvement is contributing, a more specific treatment approach is needed. An assessment identifies what is causing the sensitivity before anything is planned.
Why are my teeth sensitive to cold but not heat?
Sensitivity to cold that is brief and disappears quickly usually indicates exposed dentine rather than pulp involvement. The cold stimulus triggers fluid movement in the dentinal tubules, which stimulates the nerve momentarily. If the sensitivity lingers for more than 30 seconds after the cold is removed, this suggests the pulp may be inflamed and assessment is recommended.
Can teeth whitening make sensitivity worse?
Whitening can cause temporary sensitivity during and after treatment. The whitening agent temporarily increases the permeability of the dentinal tubules, making the tooth more responsive to temperature. This usually settles once treatment is completed. If you already have sensitive teeth, the whitening approach can be adjusted to minimise discomfort. Read more on our teeth whitening sensitivity page.
Does sensitivity mean I need root canal treatment?
Not necessarily. Most tooth sensitivity is caused by exposed dentine and does not involve the pulp. Root canal treatment is indicated when the pulp is irreversibly inflamed or infected. The key distinction is whether sensitivity is brief and triggered, or lingering and spontaneous. An assessment determines which applies.
Can grinding cause tooth sensitivity?
Yes. Grinding wears down the enamel on the biting surfaces over time, progressively exposing more dentine. Patients who grind often notice generalised sensitivity, particularly on back teeth. A nightguard helps protect the remaining enamel from further wear and can reduce sensitivity over time.
Is Penn Pacific Dental Center near Tanjong Pagar MRT?
Yes. The clinic is at 160 Robinson Road, #05-14 SBF Center, a short walk from Tanjong Pagar MRT (East-West Line). It is also accessible from Shenton Way MRT (Thomson-East Coast Line) and Telok Ayer MRT (Downtown Line).