Purpose: To assess and compare topographic features and preosteoblastic cell responses of a new hydrothermally treated, calcium-incorporated surface against other commercially available implant surfaces. Materials and Methods: Four different surfaces were the subject of comparison in this study: machined (MC), resorbable blast media (RBM), sandblasted/large-grit/acid-etched (SLA), and calciumincorporated SLA (Ca-SLA). Surface morphology and roughness were first characterized by scanning electron microscope (SEM) and white light interferometer, respectively. Preosteoblastic MC3T3-E1 cells were then cultured on the titanium surfaces. Cell morphology was observed at 24 hours, 48 hours, 7 days, and 15 days by SEM; differentiation was assessed at 7, 11, and 15 days by assaying alkaline phosphatase (ALP) activity and osteocalcin (OCN) levels. Results: Surface characterization revealed nanotopographic features on Ca-SLA. At topographic analysis, SLA and Ca-SLA showed similar roughness values. Significant differences in cell differentiation parameters were found only at 15 days between the SLA surfaces (both Ca-incorporated and nonincorporated) and MC. Conclusion: Collectively, this study demonstrated that hydrothermal treatment determines the formation of nanotopography without altering the SLA microtopography. Moreover, Ca-SLA and SLA induce MC3T3-E1 cell differentiation at comparable levels. Keywords: calcium ions, implant, implant surfaces, surface roughness, surface treatment