British researchers surveyed 15 dental association guidelines in the US, Britain, Japan and seven other countries; searched the dental literature; recorded information by toothbrush manufacturers; and read 10 dental textbooks searching for advice on how, how long and how often to brush.
The review, published in the British Dental Journal, found no randomised trials of brushing technique and very little agreement on how to go about cleaning teeth.
Some sources, like the American Dental Association, recommended the Bass technique ? holding the brush at a 45-degree angle to the gum and making short back-and-forth movements. Others preferred the Fones technique, which requires large, sweeping circles over the teeth with the toothbrush at right angles to the tooth surface.
At least three other variations were suggested by other sources.