Clinically proven to whiten between teeth (in controlled clinical testing). Introducing Johnson & Johnson Reach Whitening Dental Floss. This shred-resistant floss has a unique stain-fighting ingredient that safely polishes away stains and is gentle enough to use every day. It is clinically proven to whiten between teeth (in controlled clinical testing), where tooth stains form most. Dentists recommend regular flossing. Flossing has also been clinically proven to remove plaque between teeth to help prevent gum disease.