Summary.This study investigated the movement of root canal sealer during the placing of a gutta‐percha root filling. Using transparent simulated tooth models, three techniques of introuducing sealer were examined; these were with the gutta‐percha point, with a reamer, or with a Lentulo spiral filler. The use of a Lentulo spiral filler showed consistently more apical extrusion of sealer than with the other techniques. The results demonstrated that the overall coating of sealer was not affected by whatever technique was emplo