Dentists in England are playing the system to maximise their profits, the government believes.
An analysis of NHS paperwork suggests dentists are recalling healthy patients for check-ups and dividing courses of treatment unnecessarily.
Chief dental officer Barry Cockroft is talking to local health bosses, believing a tenth of appointments could be freed up if the problem was solved.
But dentists said there was no evidence it was happening.
The Department of Health believes the tactic has become widespread since the introduction of a new contract in 2006.
The answer is for the NHS to directly employ dentists.