Photo: The Canadian Press

A dentist at the Riley Hospital for Children Department of Pediatric Dentistry, checks the teeth of Justin Perez, 11, during an office visit in Indianapolis, Friday, Jan. 22, 2016.

The federal budget shows the government's proposed dental-care insurance program will cost more than double what the Liberals originally thought, driving it up by another $7.3 billion over five years.

Last year, the government set up a temporary benefit for uninsured children under the age of 12 in families with a household income of less than $90,000.

That benefit will be scrapped and replaced by a government-administered insurance plan, beginning with people under the age of 18, seniors and people with disabilities who don't have insurance and are at that household income level, at a cost of $13 billion over five years beginning in fiscal 2023-24.

The program is the linchpin of the Liberal's confidence-and-supply deal with the NDP to prevent an election before 2025 in exchange for progress on the opposition party's priorities.

Original estimates were based on preliminary information gathered just weeks after the federal government signed on to the deal, but government officials say those estimates have since increased as they've learned what it will really cost to administer the program.

The government plans to require all employers to report on whether their staff have benefits to help prevent anyone with existing insurance from being able to access the new federal plan.