I usually use one of these carriers to travel within Europe.
I usually take only carry on luggage. I've never tried to take in my carry-on an electric toothbrush.
If you have one of these you know that the brush head detaches from the small metal (1inch?) drive shaft.
I notice in Ryanair's list of prohibited items for cabin baggage it mentions "Pointed/edged Weapons & Sharp Objects" . It doesn't mention electric toothbrushes explicitly.
Of course the baggage is screened by security before one gets to the gates. Has anyone got an electric toothbrush through security screening and then onto the plane?
(recently Ryanair introduced a new system whereby a small carry on case will automatically go into the hold unless priority has been paid for)