The Oral-B Advanced Clean toothbrush has color changing bristles that fade from green to yellow to signal it is time to replace your toothbrush. Advanced Clean toothbrush fights tartar and plaque buildup. Advanced Reach Trim thoroughly reaches in-between teeth and tight spaces to maximize plaque removal. This medium bristle toothbrush has polished end-rounded bristles that are designed to be gentle on your teeth and gums while providing an effective clean. For the best results, change your toothbrush regularly. A new toothbrush cleans 95% better in hard-to-reach areas*. This pack of Oral-B toothbrushes include different colors of toothbrushes for households with multiple people or stocking up. Oral-B is the #1 Toothbrush Brand Used by Dentists Worldwide. *vs. one 3 months old; research with a flat trim toothbrush