Your dentist can help you determine if your teeth and gums are healthy and good candidates for teeth whitening and which whitening process will give you even, natural looking results. If the discoloration or stains on your teeth will not respond well to whitening, your dentist will have other options that will work best for you. If teeth whitening is a good option for you, in-office whitening will give almost immediate results and teeth whitening trays and gels created by your dentist can be done at home over the span of two weeks.