Yes, but does your toothbrush charge while not touching the base? That's the key here :)
It sits on the base, for that reason it's touching the base. But there are no electrical contacts between the toothbrush and the base. I could put saran wrap over the base and it would still charge.
The rechargeable toothbrush is employing an AC transformer. The primary of the transformer is in the recharger base. The secondary winding is in the base of the tooth brush. A rectifier on the secondary converts the coupled AC to DC to recharge the battery. The toothbrush doesn't have be be in direct contact, but moving away diminishes the coupling of the oscillating magnetic field.
The beauty of the design in the case of the toothbrush is that the recharging circuitry is fully sealed from the wet environment. No metal contacts to rust or corrode.