What Causes Tooth Sensitivity after Whitening?
Sensitive teeth after bleaching happens for two reasons:
- Bleaching molecules penetrate into your teeth increasing blood flow and pressure in the tooth pulp causing mild pulpitis. Although diffusion into your teeth helps amplify whitening effects since chromophore molecules in your tooth dentin can be broken up by hydrogen peroxide, the increased pressure irritates the tooth nerve slightly and makes your teeth more sensitive to stimuli in general. Everyone responds differently and this mild pulpitis can last for about 2 weeks after whitening.
- Increased tooth porosity and removal of the protective protein layer on the surface of your teeth. We talked about how maintaining the protein pellicle is important in keeping the pores in exposed dentin closed off from the oral environment. For better or worse, all whitening products must strip off this protein layer in order to dissolve surface stains. This will open up pores in exposed dentin and cause sensitivity.
How to Relieve Sensitive Teeth after Whitening
- Brush your teeth before whitening not after whitening. Brushing right after whitening will further open pores on exposed dentin and create sensitivity. It can also damage your enamel since some bleaching agents are slightly acidic. Let your teeth recover afterwards.
- Use a Desensitizing Gel to calm your the nerves in your teeth prior to whitening. For the most relief, you should apply the gel to your teeth for 10 to 30 minutes before bleaching using the same bleaching trays you got from your dentist and rinse afterwards. Ideally, the gel should contain both 5% potassium nitrate and fluoride. We are able to prescribe specifically designed desensitizing gels like UltraEZ™, Desensitize!, and Relief™, but in a pinch you can also try using in the trays a desensitizing toothpaste that contains 5% potassium nitrate. Using toothpaste instead of the commercial gels may also be a more cost-friendly method.
- Whiten as directed.
- Rinse out your mouth thoroughly after bleaching with water, or better still a pH re-balancing mouth rinse. Although bleaching companies try to make products that are pH balanced, many end up being slightly acidic. Getting your oral pH back to normal lets your teeth begin to recover.
- Use your finger (or q-tip) to gently apply to your teeth one of the Calcium-Based Desensitizing pastes. Let the paste set for a few minutes and then spit thoroughly; do not rinse for at least 30 minutes following application. By gently coating your teeth with a product like MI Paste or Colgate’s Pro-Argin Toothpaste, you will plug up open pores on your teeth and reduce sensitivity. Additionally, the remineralizing effects of these pastes help to improve whitening.