The powder and liquid are mixed on a glass slab with a spatula to form a thick paste. Although sterile water may be used, local anaesthetic solution is more readily available in the surgery. The material may be applied using a spiral root canal filler as described earlier, however some practitioners prefer to use the small plastic tube with a long fine point illustrated in Part 7, Figure 14. The mixed material is loaded into the tube and extruded directly deep in the canal.
A large paper point may again be used to condense the material further, and absorb excess water making the procedure easier and the filling more dense (Fig. 3). A firmer paste may be made by adding powder to a proprietary brand of calcium hydroxide paste. Of utmost importance in endodontics is the temporary coronal seal which prevents leakage and (re)contamination of the canal system. Intermediate restorative material (IRM), or
glass-ionomer cement are useful for periods of over 7 10 days; for shorter periods, zinc oxide, Cavit or other proprietary material may be used, as described in Part 5.