OBJECTIVETo evaluate the accuracy of marginal and internal fit of the zirconium copings manufactured by two different computer-aided design(CAD)/computer-aided manufacturing(CAM)system on the implant abutment.

METHODSUsing different scanning mode,five Procera(®) zirconium copings and five Lava zirconium copings were fabricated on the same implant abutment, and then compared with five precious metal copings fabricated by traditional method. Fifteen abutment replica were made with die-stone and the copings were randomly cemented on them, then they were sectioned and invested. The marginal, shoulder, occlusal, and axial fit of each sample was measured by scanning electron microscopy (SEM).

RESULTSThere was no significant difference in marginal and axial fit among the three groups(P>0.05). Significant difference in occlusal fit was found among the three groups(P<0.05): Lava group showed better fit than the others(P<0.05)and Procera(®) group showed better fit than the control(P<0.05).

CONCLUSIONSThese two types of zirconium coping have clinically acceptable marginal and internal fit. The internal fit of zirconium coping may be affected by different manufacturing techniques.