Setting times for endodontic sealers under clinical usage and in vitro conditions

The object of this study was to determine the set of sealers under simulated clinical versus bench-top conditions. One hundred twenty extracted teeth were divided into four groups (Roth's, Tubuliseal, Sealapex, AH26). Canal preparation and lateral condensation were performed with the four sealers (30 teeth each). Teeth were placed into 100% humidity at 37 degrees C. The same mix of sealer on a glass slab was stored within the same environment. After 1 to 8 wk the teeth were fractured longitudinally to expose the gutta-percha-sealer interface. Evaluation, both clinical and in vitro, was qualitative under a microscope with a needle tip. The degree of set was categorized as: (a) unset (smearable), (b) partially set (indented easily, but not smearable), or (3) set (not easily indentable). There were inconsistencies in setting times within and between groups. In canals most of three (AH26, Sealapex, and Tubuliseal) were partially set after 1 wk; set was complete after 4 wk. Roth's was very slow; most were unset after 8 wk. Sealers on the glass slab set much more rapidly. In conclusion, under clinical conditions, sealers set slowly (particularly Roth's) and were more delayed than when tested in vitro.