The use of two implant systems for providing implant supported overdentures in the mandible--a clinical appraisal.

The objective of this paper is to compare the Nobelpharma implant system with that designed by Astra-Tech. The main difference between the two is in the design of the fixture-abutment linkage. With the Astra system, the abutment and screw form one unit, whilst with the Nobelpharma system there is a separate abutment screw. Both systems have been used to support overdentures. Linked bar retention between two implants has been used with the Nobelpharma implants, and individual magnetic or stud retention has been used with the Astra system. Each attachment mechanism has produced patient satisfaction.