Figure 2From: In vivo wear performance of highly cross-linked polyethylene vs. yttria stabilized zirconia and alumina stabilized zirconia at a mean seven-year follow-up The photomicrographs showing the topography of retrieval heads at the pole region: (a) PSZ (aged 2.3 years in vivo), (b) ASZ (aged 1.5 years in vivo), and (c) ASZ (aged 3.2 years in vivo). PSZ head had a bumpy surface, whereas ASZ heads showed no apparent roughening.Back to article page