Triple Bypass April 12th. Questions about doctor visits going forward.

Hi, My husband had CABG X3 on April 12th. He now has some issues with his gums and needs to be seen by our dentist. Dentist says he'll need a cleaning prior to diagnosis, but cardiologist wants him to wait until 12 weeks out. So, what do we do about sore gums if he can't see the dentist. Also, has an artificial knee and prior to CABG always had to take clindamycin prior to dental visits. Is that safe after CABG? Anyone have any experience?