If crown falls off in office, what is the appropriate procedure and fair price?

A crown that has good bond strength will not come off during a cleaning.  How old was the crown? This can happen with older crowns after years of being in place.  If it was going to come off the best place for that to happen is in the dental office.  You were able to have it recemented immediately without time for tooth movement, sensitivity, or gum irritation to occur.  As far the fee goes, that varies in every office.  Good luck.  

Any crown that is well cemented to a tooth cannot be taken off by probing, scaling or other procedures.  If your crown came off it was certainly because the cement or bonding was leaking and/or failing and you should consider yourself lucky that it saved you an emergency vist to the dentist and possibly avoided a future root canal or new crown.Dentists normally charge an emergency visit plus a a fee to recement the crown.  You saved that additional charge.  The dentist probably charged you his normal fee to recement.If this was a new crown by this dentist made in the last year or two then it probably would have been done at no charge to you.Ira L Shapira DDS, D,ABDSM, D,AAPM, FICCMOChair, Alliance of TMD OrganizationsThinkBetterLife.com