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.
Door Protection - Kick Plates, Mop Plates, Armor Plates. Door protection is applied to the surface of a door to help prevent damage to the surface finish of the door. It is used most often in institutional and commercial buildings since these types of buildings see significant wear and tear to doors.