Adhesive and oxidative response of stem cell and pre-osteoblasts on titanium and zirconia surfaces in vitro.
The aim of the present study was to investigate the initial stem cell and pre-osteoblast cell adhesion and oxidative response on zirconia in comparison with titanium. Human dental pulp stem cells (DPSC) and murine pre-osteoblasts (MC3T3-E1) cells were cultured on zirconia and titanium surfaces, and at 3-, 12-, and 24-hour intervals, cell viability and morphology were determined with tetrazolium based colorimetric assay, scanning electron microscopy, and immunofluorescence analysis. The in situ reactive oxygen species level of both cells on each material surface was examined after 24-hour culture. Both DPSC and MC3T3-E1 cells revealed comparable morphological features during 24-hour cell adhesion processes, with cells continued expanding of cell size and increasing of cell viability on titanium and zirconia surfaces during 24-hour culture. Zirconia demonstrated relatively higher mean cell viability compared to titanium within 24-hour culture, with significantly higher DPSC viability at 12 hours after seeding (P < 0.05). Relatively higher mean reactive oxygen species levels in both DPSC and MC3T3E1 were found on zirconia surfaces after 24-hour culture compared to titanium. From the results, zirconia as a potential dental implant substrate demonstrated equivalent or better initial cellular responses compared to titanium.