1) It should be tacky when mixed to provide good adhesion between it and the canal wall when set.

2) It should make a hermetic seal.

3) It should be radiopaque so that it can be visualized on the radiograph.

4) The particles of powder should be very fine so that they can mix easily with liquid.

5) It should not shrink upon setting.

6) It should not discolour tooth structure.

7) It should be bacteriostatic or at least not encourage bacterial growth.

8) It should set slowly.

9) It should be insoluble in tissue fluids.

10) It should be well tolerated by the periapical tissue.

11) It should be soluble in common solvents if it is necessary to remove the root canal filling [20] .