In: Teeth Whitening
About 50% of whitening patients experience some sensitivity during treatment. Here is why it happens and the proven strategies to prevent or minimize it.
Why whitening causes sensitivity
Whitening gel contains hydrogen or carbamide peroxide. These molecules diffuse through enamel into dentin (the layer below) where they break down stain compounds. As they pass through, they temporarily dehydrate the tiny tubules that connect dentin to the nerve. Dehydrated tubules transmit thermal and pressure signals more easily - that's the cold-zinging feeling. The effect is reversible within 24-72 hours after stopping whitening.
Pre-treatment to prevent sensitivity
Start 1-2 weeks before whitening:
- Brush twice a day with a desensitizing toothpaste - Sensodyne, Crest Sensitive, or Sensodyne Repair & Protect. Active ingredient: potassium nitrate or stannous fluoride.
- Apply a small amount to teeth before bed and let it sit (don't rinse) - extra desensitizing exposure.
- Avoid acidic drinks (citrus, soda) for the week before - softened enamel sensitizes faster.
This pre-treatment cuts whitening sensitivity by 40-60% in clinical studies.
During treatment - sensitivity management
Strategies if you're already feeling sensitivity:
- Skip a day or two - sensitivity resolves quickly.
- Reduce wear time - 30 minutes instead of 60.
- Reduce gel volume - a tiny dot per tooth instead of filling the tray.
- Use desensitizing gel between whitening sessions - apply for 15 minutes before bed.
- Take ibuprofen before sessions if needed.
- Switch to a lower-strength gel - your dentist can provide a 10% or 16% carbamide peroxide instead of 22%.
Most patients can complete treatment with these tweaks. Severe sensitivity is rare and signals stopping or switching methods.
Custom trays beat OTC for sensitivity
OTC strips and trays cannot fit your teeth precisely - gel migrates onto gums, into recession areas, and onto exposed root surfaces, all of which cause more sensitivity. Custom trays from your dentist are formed to your exact teeth so gel stays on enamel surfaces only. For sensitive patients, custom trays are noticeably more comfortable than OTC strips.
When sensitivity signals a different problem
Most whitening sensitivity is temporary. Call us if:
- Pain lasts more than 5-7 days after stopping whitening.
- One specific tooth is throbbing - possible underlying issue unrelated to whitening.
- Pain to biting or pressure - different from cold sensitivity.
- Spontaneous pain without a stimulus.
- Severe pain that medication doesn't touch.
These suggest a tooth issue (crack, decay, dying nerve) that whitening uncovered, not whitening alone. We'll investigate.
Frequently asked questions
- Will sensitivity stop me from whitening?
- Almost never. With pre-treatment desensitizing toothpaste and pace adjustments, virtually all patients can complete whitening successfully.
- Are some patients more sensitive than others?
- Yes. Patients with gum recession, exposed roots, cracked teeth, or already-sensitive teeth are more likely to have whitening sensitivity. We discuss expectations at the consultation.
- Can I whiten if I have sensitive teeth normally?
- Yes, but with adjustments - lower-strength gel, shorter wear times, longer pre-treatment with desensitizing toothpaste. Most sensitive patients can still whiten successfully.
- Does sensitivity mean my teeth are damaged?
- No. Whitening sensitivity is fully reversible and does not damage enamel. It's a temporary functional change in dentin tubules, not structural damage.