Measurement of the adhesive strength of a gingival cell line to agar.

A new technique is described for measuring the adhesive strength of a gingival cell line to an agar substratum by the modification of the original "blister" test for adhesives. A cell monolayer was developed on a Petri dish with a hole in the center of the growing surface, overlayed with agar, and the system pressurized to debond the cells from the agar surface. Pressure changes were measured by a capacitance pressure transducer the output of which was measured by a strip-chart recorder. The modulus (E) of the agar overlay was determined and used in the calculation of the adhesive-bond strength (gammaalpha). The gammaalpha yield for the gingival cell line (cell-agar debond) was 48.8 ergs per cm2, and for the control (no cells) (agar-polystyrene debond) was 30.0 ergs per cm2.