The aim of this study was to clinically and radiographically examine the effects of extrusion of AH Plus sealer on the healing of permanent teeth with apical periodontitis. A total of 87 root canals radiographically detected with apical periodontitis were included in the study. Posttreatment radiographs indicated sealer extrusion into 49 canals (Group 1) and no sealer extrusion into 38 canals (Group 2). Periapical treatment was judged as complete healing (CH), incomplete healing (IH) and no healing (NH) at the end of a 4-year follow-up period. Amounts of extraradicular sealer were recorded as "unchanged," "reduced," "almost absent," or "absent." The t test was used for the statistical analyses. In Group 1, CH was detected in 41 canals, IH in 4 canals, and NH in 4 canals. Differences between CH and both IH and NH were statistically significant (P < .001). In Group 2, CH was detected in 34 canals and NH in 4 canals. The difference between CH and NH was statistically significant (P < .001). A statistically significant difference (P < .05) between treatment groups was observed for CH at the 6-month follow-up appointment only; other than that instance, there were no statistical differences for CH or NH between the groups. In conclusion, extruded AH Plus does not prevent periapical healing, but can be a delaying factor for healing in children.