My Husband's Dentist Prescribed A Course Of Penicillin VK 500

My husband's dentist prescribed a course of Penicillin VK 500 mgs to treat several abscessed teeth, but he is afraid to take it because he had C-diff 5 years ago. Since then, he has been taking daily probiotics (1 billion active cultures. Our pharmacist advised that he should be okay as long as he takes the probiotics, but he is still resisting. Do you see a problem with this? I feel the the abscess could do more harm than the chance of C-diff reoccurring. He just needs some reassurance from a higher authority.