Can crest 3d toothpaste make your smile whiter? enamel renewal and stain protection ?

To a point: It does contain whitening ingredients and does protect the enamel with fluoride. I don't believe it can protect against acquiring new stains, but a toothpaste can remove fresh stains if used regularly.

Probably not: A lot of the advertisements you see on television for toothpaste, mouthwash, and toothbrushes are overly dramatized. These ads are designed to make you buy more products at inflated prices. Toothpaste does not really work to whiten because the whitening agent is not on your teeth long enough. The most economical way to effectively whiten is with custom made trays and whitening gel from a dentist.

Possibly: This product claims to whiten teeth as well as renew your enamel and fight stains. I have not tried it myself. In theory it should help reduce staining caused by smoking, coffee and tea on the surfaces of teeth, but will probably not eliminate them all together. It will not help teeth with discolorations due to malformation or decay.

Somewhat: Unless a toothpaste contains peroxide, there is no active ingredient that will physically whiten someones teeth beyond the color they currently are. What toothpastes contain are abrasives and polishing agents which physically remove surface stain only.