I'm scheduled for a porcelain/metal abut. (one missing tooth) Does anyone know the difference between an abut. and a crown? Also, I had to go in to see the dentist with a problem with one of the teeth to be worked on - the dentist said that I had a sinus infection and it was affecting the roots, he gave me a rx. to take and said to come back in 2 weeks to have the abut. done. I'm uncomfortable with the information my dentist has given me and I don't understand exactly what he will be doing. My tooth is still bothering me and I'm wondering if an abut. should be done on a tooth that may not be healthy. Any insight would be greatly appreciated.