Most Common Causes of Tooth Sensitivity in Adults
The most common causes of tooth sensitivity in adults include gingival recession exposing root surfaces, enamel loss due to abrasion and erosion, and dentin exposure through various mechanisms that allow external stimuli to trigger nerve responses in the pulp.
Understanding Tooth Sensitivity
Tooth sensitivity (dentine hypersensitivity) occurs when the dentin becomes exposed to the external oral environment, allowing thermal, chemical, mechanical, or bacterial stimuli to trigger pain responses. This pain is typically sharp, well-localized, and brief in duration.
Anatomical Basis for Sensitivity
When examining tooth sensitivity, it's important to understand the tooth structure:
- Enamel covers the crown portion
- Cementum covers the root surface
- Dentin lies beneath both and contains tubules that communicate with the pulp
- The pulp contains nerve fibers that respond to stimuli 1
Primary Causes of Tooth Sensitivity
1. Gingival Recession
Gingival recession is a major contributor to tooth sensitivity as it exposes the root surface, which is not protected by enamel. This exposure occurs due to:
- Periodontal disease
- Aggressive tooth brushing techniques
- Aging (natural recession with time)
- Periodontal treatments 2
Adults with gingival recession are particularly susceptible to root surface sensitivity, especially as they age and retain their natural teeth longer 3.
2. Enamel Loss
Enamel can be lost through several mechanisms:
Abrasion:
- Caused by mechanical forces
- Often related to aggressive tooth brushing with hard bristles
- Use of highly abrasive toothpastes
- Improper brushing technique 4
Erosion:
- Chemical dissolution of tooth structure
- Primarily caused by dietary acids (acidic foods and beverages)
- Gastric acids (reflux disease, frequent vomiting)
- Environmental acids 5
Attrition:
- Tooth-to-tooth wear
- Often related to bruxism (teeth grinding)
- Malocclusion leading to abnormal wear patterns 4
3. Dental Procedures
Various dental treatments can temporarily or permanently increase tooth sensitivity:
- Restorative procedures that alter enamel and dentin architecture
- Professional cleaning
- Tooth whitening treatments
- Orthodontic treatment 1
4. Cracked Tooth Syndrome
Cracks in teeth can lead to sensitivity that may be difficult to diagnose:
- Often caused by occlusal forces
- May result from large restorations weakening tooth structure
- Thermal cycling (hot/cold alternation) can exacerbate symptoms 1
5. Caries and Decay
Dental caries can lead to sensitivity when:
- Decay reaches dentin but before pulpal involvement
- Recurrent decay around existing restorations
- Initial demineralization of enamel 3
Mechanism of Sensitivity
The hydrodynamic theory explains how these various causes lead to pain:
- Exposed dentin tubules allow fluid movement within the tubules
- External stimuli (cold, air, touch) cause this fluid to move
- Movement activates mechanoreceptors (A-delta nerve fibers) in the pulp
- The brain interprets this as sharp, sudden pain 6
Risk Factors for Increased Sensitivity
Several factors can increase the risk of developing tooth sensitivity:
- Poor oral hygiene (paradoxically, overly aggressive hygiene as well)
- High consumption of acidic foods and beverages
- Bruxism or clenching habits
- Aging (increased risk of recession)
- Certain medications that reduce salivary flow 2, 5
Clinical Significance
Tooth sensitivity affects approximately one in seven dental patients 2. As the population ages and more people retain their natural teeth longer, the prevalence of sensitivity is likely to increase. The condition significantly impacts quality of life by causing pain during everyday activities like eating, drinking, and breathing cold air.
Understanding these causes helps clinicians develop appropriate management strategies, which may include desensitizing agents, restorative procedures, or addressing underlying causes such as improper brushing techniques or dietary habits.