If you clench or grind, discuss it before whitening; enamel wear and exposed dentin can increase level of sensitivity

https://telegra.ph/Can-You-Bleach-Teeth-with-Braces-A-Guide-to-Timing-04-16

If you clench or grind, discuss it before whitening; enamel wear and exposed dentin can heighten level of sensitivity, requiring tailored procedures and gentler gels.