Are there any dangers of using tooth whitening kits that use 35% carbamide peroxide?

Maybe: 35% is pretty strong for home use. Follow instructions to the letter. At this strength sensitivity can be an issue. Limit the time u use it and keep it off of tissues. It can burn the tissues. Discontinue use if any problems arise.

Be careful: 35% carbamide peroxide sounds a little too strong to be used without supervision. I suggest you see your dentist and bring the kit with you so he or she can give you some tips and guidance with its use.

Possibly: 35% is very strong for home use, and if the material seeps onto your soft tissues there is a strong chance you will have chemical burns. Proceed with caution.

Usually, no: The higher the %, the shorted the wear time. We use a 32% solution that you wear for only 3 minutes. Any sensitivity you might have is usually reversible and only requires a day or two off.