I will derive the gravitonic Casimir effect with non-idealized boundary conditions. This allows the quantification of the gravitonic contribution to the Casimir effect from real bodies. I will show how to use this formula to calculate the meagre gravitonic Casimir effect in ordinary matter. I will also apply this formula to the speculated Heisenberg-Couloumb (HC) effect in superconductors, thereby providing a test for the validity of the HC theory, and, consequently, the existence of gravitons.