Bioactive glass (6P55), used for coating Ti/Ti-alloy, was tested for its in vitro behavior in a comparative study with commercial Bioglass™ (45S5) and commercial titanium alloy (Ti6Al4V). In vitro testing included pH and dissolution rate determination in simulated body fluid (SBF) along with in vitro cyto-compatibility testing. Similar dissolution behavior was seen for 6P55 and 45S5, demonstrating t1/2 dependence and maximum pH of approximately 8.1 after 10 days of immersion. The dissolution rate of these glasses approached 0 after 15 days of immersion, which resulted in pH stabilization at less than 7.5. Cell culture studies showed that both glasses behaved in a similar fashion after 16 hours in culture. Both glasses had an increase in cell numbers of approximately 200-250%, whereas Ti6Al4V had a less pronounced cell number increase (∼ 180%) relative to initial cell seeding density.