The Mission of Mercy Free Dental Clinic traditionally held in the spring has been moved to the late summer this year.
It takes hundreds of dental volunteers to see hundreds of patients in those two days.
One man in charge of recruiting recently made a trip to the White House as he was honored for his efforts.
Thursday, volunteers are setting up at the Roanoke Civic Center and pre-screening patients before the real work begins Friday.
Dr. David Black one of the founding organizers was given the Daily Point of Light Award this summer.
He works to get more dentists to volunteers, so ultimately more patients can be seen.
When the work is done at the end of the two days he says satisfied to one degree yet still sad.
"I get two feelings. The first is I'm very proud and happy. The other is that we've barely scratched the surface, I do have a sadness too," Dr. Black said.
This year Dr. Black says more than 60 dentists have signed up to help, that's actually fewer than before.
In past years they've seen as many 900 patients, but this year they're hoping to help 800 folks.
In the past five years volunteers have provided $5 million in free services to 5,000 patients.