If you clench or grind, discuss it before whitening; enamel wear and exposed dentin can heighten sensitivity
https://www.mediafire.com/file/wm32te5dhzxhx00/pdf-8349-8921.pdf/file
If you clench or grind, discuss it before whitening; enamel wear and exposed dentin can increase level of sensitivity, needing customized procedures and gentler gels.