Biological characterization of surface-treated dental implant materials in contact with mammalian host and bacterial cells: titanium zirconia.

Commercially pure titanium (cpTi) remains the material of choice for dental implants due to its surface properties which promote osseointegration. Recently, zirconia (ZrO) has been used as an alternative material due to its immunity to corrosion, mechanical strength, and biocompatibility. Previous studies evaluating oral bacterial attachment and mammalian host cell response to cpTi and ZrO have yielded mixed results. Thus, the aim of the present study was to systematically evaluate the growth of early-colonizing oral bacteria and mammalian host cells on cpTi and ZrO after three clinically-relevant surface treatments: polishing, acid-etching, or sandblasting. Polishing produced smooth surfaces (Sa: 0.08-0.22 μm) while acid-etching (Sa: 0.75-1.20 μm) and sandblasting (Sa: 0.87-1.00 μm) yielded rough variants. All surfaces were relatively hydrophilic ( ≤ 31°). Overall, the adherent bacterial count did not significantly differ between cpTi and ZrO after 1 or 3 days for all strains ( > 0.05). Bacterial count was only greater on rough smooth variants for and . Acid-etched cpTi induced the highest proliferation of macrophages and fibroblasts but the lowest for pre-osteoblasts after 1 and 3 days. All surfaces exhibited comparable fibroblast and pre-osteoblast proliferation by 7 days. Pre-osteoblast differentiation continually increased between 7 and 14 days and was higher on rougher surfaces. No differences in mammalian cellular attachment on cpTi and ZrO were observed. Within the study's limitations, early-colonizing oral bacterial adhesion and mammalian cell growth is similar on both smooth and rough cpTi and ZrO.