If you have a permanent crown that only lasted a year, it would depend on the office you went to and their policies and warranties on crowns. In our office, we have a 1-2 year warranty on all of our crowns and veneers. If anything should happen we cover it 100%, unless it came out due to patient negligence. Certain labs also have their own warranties on crowns that they can pass along to the dentist. If insurance is involved they may not pay to redo the crown if there is a replacement limit. It's typically in the best interest of the dentist to listen to the patient, take their individual case into consideration, and redo the crown at no charge to retain good customer relations. Of course, it's all based on a per case basis.