239 dentists pulled out of a scheme for medical-card patients in the space of 15 months.
They withdrew between January of last year and this March - leaving less than 1,100 dentists are currently signed up.
The scheme entitles medical card-holders to limited services, like two fillings a year.
President of the Irish Dental Association, Caroline Robins, says it needs a radical overhaul.
"If my patient needs gum treatment, that's what I should be able to provide them, not be told that I can give them two fillings a year when they may not need two fillings in a year.
"It's a very constrained scheme and it's broken, and like any industry or profession throwing money at it isn't solving the problem."
