I have philips zoom nitewhite kit that my dentist gave me, it has expiration of 7/14, is it still safe to use?

Expiration date: Call your dentist and let them know about the date, maybe they have a sample that it's expired. Generally with liquids and creams you don't want to go beyond 6 months from the expiration date to use it safely and effectively.

Expired zoom: The expiration date tells you of when the manufacturer believes that the material will still be at full strength. After the expiration date the whitening gel will slowly lose strength. It should not be harmful to you, but it may not work as well as if it was before the expiration date.

Should be fine: You should be fine as far as using the product, but to be sure, I would call your dentist or even the manufacturer of the product.

It is safe: the gel is still active for a minimum of two-three years past the expiration date. It will degrade and change the color, if stored at length in a very hot environment.