The refills for Proxbrush Classic interdental brushes have nylon monofilament bristles coated with chlorhexidine, an antibacterial agent, which effectively removes dental plaque. The diameter is 1.4mm, allowing them to fit into tight spaces. The refills are very easy to apply and protect the brushes that have not yet been used. The antibacterial protection on the refills can inhibit bacterial growth for up to 2 weeks.