This study examined the adjustments, repakirs, time, and costs required to maintain 69 implant prostheses in private prosthodontic practice for an average of 22 months, after placement. For the removable prosthesis design, the most common adjustment was contouring the prosthesis and the most common repair was retentive component replacement. Screw tightening or fracture repair wer e the most frequently needed modifications for fixed implant prostheses. Each removable implant prosthesis averaged four times as many postplacement adjustments and almost twice as many repairs as did each fixed implant prosthesis, and the mean length of each maintenance appointment was also longer for removable prostheses. Mean repair costs were approximately 60% higher for the removable design.