The American Dental Association advises against bleaching dentures. Over repeated cleanings, the bleaching process may also whiten the pink part of the dentures as well.
Although the ADA discourages bleaching, there are several other solutions that for whitening dentures. Using one part vinegar mixed with one part water to soak dentures for a span of 20 to 30 minutes aids in whitening, according to LiveStrong.com. A mixture of 1 teaspoon of baking soda in 8 ounces of water can also effectively brighten dentures when they soak for 20 to 30 minutes.
If bleach is an absolute necessity, LiveStrong.com recommends a solution of one part bleach to 10 parts water.