I have a keen interested in teeth whitening and have sent an inquiry to a dental centre. However, if there are any dentists or dental experts here who can clarify, I would appreciate your response.

I am interested in your teeth whitening services and have some questions as follows :-

1) Please advise on your procedure and method or teeth whitening options. Will the outer layer of the teeth be scaled off, or an additional white layer is added onto the teeth? If it is additional layer that will be added, please advise what is this material.
2) Will the teeth whitening bring ill-effects to the person in terms of health. For example, if a white layer is added onto the teeth to make it white, over time when we chew food, will the material get mixed up with the food and go into the internal system, bringing adverse effects to the internal organs
3) How long will the whitened teeth last
4) How much does the teeth whitening cost