All of the electric toothbrushes in this guide have been through the same testing protocol by the Live Science team.
First, we run the toothbrush on its various settings and measure how loud it is with a decibel counter app. We then compare these results to other appliances and noise levels. We run and use the toothbrush on its different settings and modes, noting any differences in intensity and durations between settings. We also test the charging process, including how long it takes to reach a full charge, and for the battery to deplete. Finally, we submerge each toothbrush underwater for the length of a brushing cycle to test its water resistance.