When it comes to professional whitening, there are two main types: the same-day whitening and those that are done over a period of two weeks. Same day whitening is done in the dental office to provide immediate results. The other type of professional whitening is the two-week bleaching. In this case, the dentist makes an impression of the patient's teeth. A mouthpiece is then made for the professional whitening kit. Individuals should have their teeth whitened before getting any other cosmetic dental work done. Otherwise, there it may be difficult to get the colors to match.