An oral care appliance (100) such as an electric toothbrush utilizing non linear resonant systems is described herein. In one exemplary embodiment the oral care appliance includes a longitudinal shaft (102) a brush head (130) and a handle (190). The handle includes a motor (140) that generates a first amplitude (404)for the brush head based on the brush head being outside of the user s mouth when no mass is applied to the brush head. In response to the brush head being inside of the user s mouth when mass is applied such as by pressing the brush head against the teeth the motor causes a second amplitude (410)to be generated for the brush head that is larger than the first amplitude.
