What causes sudden tooth sensitivity?

What Causes Sudden Tooth Sensitivity?

Sudden tooth sensitivity occurs when the protective enamel layer is lost or when gum recession exposes the underlying dentin layer, allowing external stimuli (hot, cold, sweet, acidic foods) to reach the nerve through open tubules in the dentin. 1

Primary Mechanisms of Sudden Sensitivity

The most common causes of sudden tooth sensitivity include:

• Exposed dentin from gum recession - This is the primary cause of dentin exposure and the major predisposing factor for tooth sensitivity, affecting 15-20% of adults, with peak incidence between ages 30-39 2, 3

• Enamel loss from tooth wear - Loss of enamel through abrasion (aggressive brushing), erosion (acidic foods/drinks), or grinding exposes the dentin layer underneath 4

• Dental trauma causing dentin exposure - When a tooth fracture extends into the dentin layer (beyond just enamel), there is frequently sensitivity to air, food, or beverages 1

• Recent dental procedures - Teeth can become sensitive within 3-6 months following dental work due to nerve irritation 1

• Cracked teeth (infractions) - Even microscopic cracks in enamel can allow stimuli to reach the dentin 1

How Pain Occurs: The Hydrodynamic Theory

The pain mechanism works through fluid movement in tiny tubules within the dentin that connect to the tooth's nerve. 2, 3

• External stimuli (cold, heat, sweet, acidic substances) cause fluid to move rapidly within these open dentin tubules 2
• This fluid movement activates nerve fibers inside the tooth through a mechanoreceptor response, producing the characteristic sharp, shooting pain 2
• For sensitivity to occur, the dentin tubules must be both open to the mouth environment AND patent (connected) to the pulp where nerves reside 2

Risk Factors That Predispose to Sudden Sensitivity

• Poor oral hygiene with plaque accumulation - Studies show individuals with inadequate plaque control experience more root hypersensitivity than those with better oral hygiene 4

• Periodontal disease or recent periodontal treatment - These conditions commonly lead to gum recession and root surface exposure 5, 6

• Acidic diet - Frequent consumption of acidic foods and beverages erodes enamel over time 4

• Aggressive tooth brushing - Can cause both enamel abrasion and gum recession 4

• Age-related factors - Enamel loss and gingival recession tend to worsen with advancing age, making sensitivity increasingly common as people retain their teeth longer 4

Immediate Management Algorithm

For mild sensitivity: 7

• Use desensitizing toothpaste containing potassium nitrate twice daily
• Apply fluoride-containing mouth rinses
• Avoid triggers: crunchy, spicy, acidic, or very hot/cold foods and drinks

For moderate to severe sensitivity: 7

• Seek professional application of fluoride varnish (the most effective first-line treatment recommended by the American Dental Association)
• Consider high-concentration fluoride products for home use
• Use NSAIDs such as ibuprofen for acute pain (acetaminophen if NSAIDs contraindicated)
• Obtain dental referral for evaluation of underlying causes

Critical Red Flags Requiring Immediate Dental Referral

Seek same-day dental care if: 7

• Severe pain that doesn't respond to over-the-counter pain medication
• Visible tooth fracture with possible pulp (nerve) exposure
• Severe tooth mobility or displacement
• Sensitivity persists after 4 weeks of using desensitizing products 8

Common Pitfalls to Avoid

• Delaying dental evaluation for persistent sensitivity - Sensitive teeth may indicate serious problems like deep decay, pulp exposure, or tooth fractures that need prompt professional care 8

• Assuming all tooth pain is simple sensitivity - Other conditions can mimic sensitivity, including dental abscesses, cracked tooth syndrome, and referred pain from temporomandibular joint disorders 1

• Using water to rinse tooth fragments - If a piece of tooth breaks off, never store it in water as this causes cell damage; use milk or saliva instead 1