To stay fresh and germ-free, all retainers need proper cleaning. A Hawley-type retainer can be brushed gently with a regular toothbrush — but a brush may scratch the clear aligner types. Denture cleaners, in powder or tablet form, as well as special retainer cleaners, can be used to clean most removable retainers. Fixed retainers are cleaned by brushing and flossing; a floss threader or interproximal brush can also be a helpful cleaning tool when needed.