We all have different size interdental spaces. Finding the right size brush or pick is mostly trial and error. The head should fit comfortably but snuggly between your teeth, that’s how you’ll remove the most plaque. Never force the interdental in, go down a size instead. Depending on your interdental spaces, you may need more than one size. All of our interdentals come in multiple sizes. GUM® SOFT-PICKS® exist in 3 sizes and easily slide in all interdental spaces. GUM TRAV-LER® is available in 9 different sizes and GUM Proxabrush® has replacement brush heads in 6 sizes.