Broken Canines

This is not one of my dogs, this is my boyfriend's mom's GSD. He broke his two lower canines somehow in half. The root is exposed, but he's still eating normally and chewing tennis balls so he's apparently not in pain. Anyway, she can't afford to get those two teeth removed by the vet so she's just leaving it alone. I thought this was a bad idea. When Spirit broke an upper incisor my vet told me I had to have it removed immediately to prevent an infection as it leaves a channel for bacteria to get into and can create problems. I had hers pulled. How bad is it if she leaves those two teeth alone? I can't pay for it, her xmas present from me will be the spaying of one of her other GSDs that she can't afford to get done but at least wants her spayed. This dog with the broken teeth is her service dog and he's about 7 or 8 yrs old. She said her vet wanted $400 to pull the teeth and that's way out of her price range (and mine).