Bleaching techniques and products have been used for many years without reports of any damage to teeth or gums. Bleaching is considered entirely safe.

No zero sensitivity, but occasionally patients experience some mild transient sensitivity

No, natural teeth rarely look too white.  

This technique takes a little more time and a little more effort, but will result in whiteness beyond what any other recognized bleaching technique can create, and a result that is absolutely permanent with easy periodic maintenance at home. 

If you have ever wondered; "How quickly can you whiten your teeth?", then you are not alone. There is no single answer to this question. Some people get results just in a two sessions, other need much longer treatment. How quickly the teeth whiten will depend on several factors. The first factor is the method of teeth whitening you use. The dentist supervised teeth whitening, will produce better results compared to over the counter whitening products like tooth bleaching trays or whitening strips. The second factor is the color of your teeth. If they are a yellow shade chances are that you’ll see results relatively fast.

There are many factors affecting the color of your teeth. One of the most important factors affecting the color of your teeth is actually your genes. If your mother and father have naturally yellow teeth, then chances are that you will have a similar teeth color.

Causes of Yellow Teeth

Among the primary reasons of yellow teeth (aside from your genes) are food, oral hygiene, and aging. Most of everyday food that we consume contains chromomeric ingredients that are used by manufactures to impart coloring. Food and drinks such as tea, coffee, wine, and certain fruits like berries contain color impurities which stain white teeth. Smokers should also be aware of the fact that tobacco is not only harmful but cause permanent discoloration. Secondly, poor dental hygiene is another major cause of concern. 

There's no evidence to date that the teeth whitening process has a harmful effect on the health of a tooth's nerve. 

Over 10 years of clinical use of teeth whitening products containing 10% carbamide peroxide have not shown any damage to existing fillings. The issue is not "damage" to existing restorations; rather, keep in mind that existing restorations such as tooth-colored fillings, crowns, bonding, veneers, and bridges do not lighten. This means that any pre-existing dental work may need to be replaced to match the new tooth shade achieved in the natural teeth, should a bleaching process proceed.

Studies of teeth whitening products using 10% carbamide peroxide showed little to no effect on the hardness or mineral content of a tooth's enamel surface.

Teeth Whitening is not permanent. People who expose their teeth to foods and beverages that cause staining may see the whiteness start to fade in as little as one month. Those who avoid foods and beverages that stain may be able to wait one year or longer before another whitening treatment or touch-up is needed.