Do powered toothbrushes contaminate toothpaste with metals?

Replaceable brush units of powered toothbrushes (PTBs) can contain metal parts made of nickel and chromium bearing alloy. These alloy ingredients have allergenic potential, and may contaminate toothpaste and the mouth during use. Here I quantify metals abraded from PTBs. A leading brand of PTB was used in a simulated intraoral environment with three leading brand toothpastes, and post-brushing samples were analysed for iron, chromium, nickel, molybdenum, and manganese by certified laboratories using standard methods. Results showed tartar control toothpaste abraded most metal, and caused discolouration of toothpaste slurry. Discolouration of toothpaste slurry, as a useful indicator of metal abrasion, was limited to one toothpaste brand, and not useful across brands.