In endodontics, the root canal filling should not only provide an impermeable barrier to fluid and bacterial ingress, the material must also be biologically compatible following insertion into a chemo-mechanically instrumented, cleansed, and shaped root canal system (Schäfer, 2000).
Usually, it is necessary to use two different filling materials. To date, no single material has been shown to fulfill all the above mentioned prerequisites. The root canal filling material most commonly used worldwide is gutta-percha. Regardless of the clinical technique used to compact gutta-percha within the root canal, use of this material without simultaneous application of a root canal “sealer” will inevitably result in some inadequately obturated sections of the root canal (Tagger et al., 1994).
However, even today, most sealers cannot be relied on to maintain the treated root canal in a completely sealed state, because—and especially with larger paste volumes—almost all root canal sealers contract on setting, which can lead to less than satisfactory adaptation against the root canal wa/>