This is the million dollar question.
Its all a myth. If performed correctly by a dental professional or using at home products as instructed by your dentist it is considered safe.
Here’s why teeth whitening doesn’t harm your teeth:
1. Removal of surface stains: whitening agents work to break down and remove stains such as tea, coffee, red wine, tobacco and certain foods.
2. Temporary tooth sensitivity: One of the most common side effects. Whitening briefly opens the pores in the enamel allowing bleaching agents to penetrate, although this goes away after a short period.
3. Proper application: follow instructions and recommendations from your dentist.