Disadvantages of In-Office Whitening. 1  In-office bleaching is more expensive than take-home alternatives. 2  Its cost, on average, is $650, compared to $400 for take-home trays and under $100 for over-the-counter bleaching trays or whitening strips.
Planetary protection is a guiding principle in the design of an interplanetary mission, aiming to prevent biological contamination of both the target celestial body and the Earth in the case of sample-return missions.
1 Planet Protectors Club - Planet Protectors create less waste in the first place! Find games, activities and reading materials to help save our planet from too much waste.  Roofus' Solar and Efficient Neighborhood - Find out how Roofus' Solar Home is energy smart and what makes it run.