Another pinner wrote: After being in dentistry for 20 years.. Let me tell you a cheap secret. All tooth whitening is made of peroxide. The gels run from 6 percent peroxide to 32 percent peroxide. If you swish with hydrogen peroxide everyday you will have the same results plus excellent gum tissue! As a dental hygienist, I recommend swishing with peroxide for 1-2 minutes morning and night to all my patients. It kills bacteria that causes decay, gingivitis, periodontal disease.