I think that the power brushes might stand as a convenience for the elderly when they become weak... and don't forget the fellow that was born with no arms and legs! He has to use a power toothbush everyday to clean his teeth. Poor guy, but at least he is still a happy man and preaches the word of God with such pride.
Anyway, I use a manual toothbrush, and with my thoroughness I get by just fine!
I think it is the toothpaste that does the job sometimes. It is the formula that does the job...
"Pearl Drops! The toothpaste that more dentists use."
"Disclaimer: The dentists are those whom we have paid a princely sum to say that they actually use Pearl Drops when they really don't."