Behavior of CAL72 osteoblast-like cells cultured on zirconia ceramics with different surface topographies

Because of its inherent strength, biocompatibility, and tooth-like color, zirconia ceramics have the potential to become an alternative to titanium as dental implant material. This study aimed at investigating the osteoblastic response to yttrium-stabilized tetragonal zirconia polycrystal (Y-TZP) with different surface topographies.

CAL72 osteoblast-like cells were cultured on machined (TZP-m), airborne particle abraded (TZP-s), and airborne particle abraded and acid-etched Y-TZP (TZP-sa) surfaces. Polystyrene and airborne particle abraded with large grit and acid-etched (SLA) titanium served as a reference control. The surface topography was examined by scanning electron microscopy (SEM) and profilometry. At culture days 3, 6, and 12, cell proliferation, at day 12 cell morphology, and cell-covered surface area were determined.

The surface roughness of Y-TZP was increased by airborne particle abrasion and additionally by acid etching. No statistically significant differences were found between average roughness (R(a)) and maximum peak-to-valley height (R(p-v)) values of airborne particle abraded and acid-etched Y-TZP and SLA titanium. Whereas the cell proliferation assay revealed statistically significant greater values at day 3 for surface-treated Y-TZP and polystyrene cultures as compared with machined Y-TZP, no differences between the Y-TZP groups, SLA titanium, and polystyrene were observed at culture days 6 and 12.

Cell morphology and cell-covered surface area were not affected by the type of substrate. The results suggest that roughened Y-TZP is an appropriate substrate for the proliferation and spreading of osteoblastic cells.