Initial responses of osteoblasts on microstructured high energy titanium surfaces

OBJECTIVES: Modifications of implant surface topography and surface energy intend to promote osteogenic cell activation in order to enhance implant healing. Aim of the present study was to monitor early osteogenic cell attachment, proliferation and differentiation on surface modified titanium disks.

METHODS: Ti disks were manufactured to present three different surface properties: smooth pretreatment (PT), sandblasted/acid-etched (SLA) and modified sandblasted/acid-etched (modSLA) surfaces to retain high surface energy (Straumann, Basel). Human osteogenic cells were cultured on the respective surfaces for up to 3 days and the following responses were analysed: cell shape, cell count, proliferation activity, and cell differentiation (by quantitative immunohistochemistry: alkaline phosphatase [ALP], collagen [COL], bone sialo protein [BSP], osteocalcin [OC], normalized to beta-actin and GAPDH).

RESULTS: Compared to PT, cells on SLA and modSLA showed a fast and plane adhesion. During the whole observation period, cell counts and proliferation activity were lowest for the modSLA surface. Conversely, cell differentiation was highest for the modSLA surface with significant higher ALP, COL and BSP levels. For the late differentiation marker OC, no difference was observed.

CONCLUSIONS: In this in vitro experiment high energy surfaces compared to standard surfaces seem to direct human osteogenic cells into a well-attaching and fast differentiating phenotype.