Brian Maixner has had dental problems since he was a child but has never been able to afford to fix them.
Attorney Fred Boettcher, a customer at the Doo Dah Diner where Brian works, saw the waiter's smile and was reminded of his own childhood dental misfortune.
"I was trying to wait on their table, but I was crying a bit."
"I just keep staring in the mirror and going, 'wow'," he added.
"It just makes such a huge difference. Before, I was conscious about my smile, not that I could stop it. Even when my teeth were bad, I still smiled.
"I’m enjoying the heck out of this. It’s a whole life changer."
Boettcher is well known as a charitable person in his home town of Ponca City, Oklahoma, having donated dental work to other people who shared the pain of bad teeth.
"He’s an incredible, incredible person," one of his colleagues told USA Today. "He always does this for people and never wants any credit."
Brian has been travelling back-and-forth to Ponca City to visit Boettcher's dentist, and still has a lot of work left to do. His teeth should be complete by the end of 2015.