Response of MG63 cells cultured on tissue culture polystyrene and Ti surfaces: (A) cell number, (B) alkaline phosphatase specific activity in the cell lysate, and (C) osteocalcin levels in the conditioned medium. Cells were cultured on control (TCPS), PT, SLA, and modSLA Ti surfaces. Values presented are mean ± SEM of six independent cultures. The data presented are from one of two separate experiments with comparable results. Data were analyzed using ANOVA and statistical significance between groups was determined using Bonferroni's modification of Student's t-test. *p< 0.05 vs. TCPS; ·p<0.05 vs. PT; Φp<0.05 vs. SLA.