These strips promise to be a simple and effective way to brighten your smile Crest’s whitestrips are popular for good reason. And the range is available in an array of different variations, from strips for sensitive teeth (was $49.99, now $27.86, Amazon.com ) to fast-tracked one-week whitening courses (was $44.99, now $29.99, Amazon.com ) — there’s no denying the brand has your pearly whites covered. Perhaps the most popular offering from Crest is its professional effects course (was $45.99,