Bacteria guard bristles. No. 1 used by dentists worldwide. Bacteria guard bristles help keep your brush clean for up to 3 months (Inhibits microbial growth that may affect the bristles. The bristles do not kill the bacteria in the mouth or protect you against disease. Always the product thoroughly after use). www.pg.com. www.oralb.com. Customer Service Number: 1-800-56-OralB. Made in Germany.