The aim of this study was to establish a new FSS model that is easy to use as well as simple to assemble in order to create reproducible fluid shear forces on cells close to implant material surfaces. Todays’ commonly used commercial flow devices differ in geometry and function, which makes comparisons between experiments difficult. The benefits of this novel testing device are reproducible laminar flows under controlled conditions (regulated temperature as well as steady partial pressure of CO₂). Due to its reproducibility, the stimulation of osteoblast cells by shear forces becomes assessable.

In this FSS chamber, osteoblasts were cultured on the bottom of a rotating round glass panel that moves within a resting liquid. Computerised simulations determined a value of 200 rpm as the optimal system configuration in which a constant laminar flow occurs without pulsatile character. When creating laminar flows, induction of turbulences at boundary surfaces results in flow instability. To reduce this negative effect occurring in frequently used stationary devices, cells were cultured on a carrier plate, which is placed within the lower petri dish. In this context, the direct contact between the carrier plate and another interface was omitted. Laminar flows were chosen to achieve a good reproducibility. This required a flow profile that is characterised by parallel moving liquid layers that are present in the area in between the upper and lower plate. To define the most favourable position of the cell-bearing surface, computerised simulations were performed. Herein, it could be demonstrated that rising shear forces along the plate surfaces’ (0–2 dyn/cm²) are too low for osteoblast test cell stimulation, which occurs at about 10 dyn/cm². The bottom of the glass plate generated enough shear forces (10 dyn/cm² in the periphery) to meet the requirements of an osteoblast-stimulating laminar flow chamber.