The effect of ultrasonics on sealer distribution and sealing of root canals.

The purpose of this study was to compare the ultrasonic and hand methods of sealer placement using three types of sealers: Sultan "Grossman's formula," AH-26, and CRCS. The effect of these methods on radiographic density, sealer distribution, and on the apical seal of the different sealers was evaluated. The in vitro experiment was carried out using human extracted mandibular incisors and mesio-buccal roots of maxillary first and second molars. Following standardized canal instrumentation, 120 single canal mandibular incisors were randomly assigned to six groups, depending on the type of sealer and method of sealer placement (hand versus ultrasonic). An additional ten teeth were used as controls. In the molar groups 40 canals were randomly assigned to two groups, with the method of sealer placement as the variable. Eight canals were used as controls. Postsealer analyses using radiographic density scores transformed to mm of sealer indicated that ultrasonics was superior to manual placement only for CRCS. Taken together, our investigation suggests that ultrasonics may enhance the placement of some sealers (i.e. CRCS) but not of others (i.e. AH-26 or Sultan). Method of sealer placement had no effect on apical leakage and therefore apparently on apical seal.