A Micro-CT Analysis of Apical Debris Extrusion Using Different Irrigation Activation Protocols

Abstract

Apical debris extrusion remains a major concern in endodontic therapy, as it can trigger postoperative pain and periapical inflammation. This study aimed to evaluate and compare the extent of apical debris extrusion associated with different irrigation activation protocols using Micro-Computed Tomography (Micro-CT) analysis. Forty extracted single-rooted human teeth were prepared and randomly divided into three experimental groups: ultrasonic activation, sonic activation, and conventional syringe irrigation. All specimens were irrigated with sodium hypochlorite under standardized conditions. Following instrumentation and irrigation, the extruded debris was collected and analyzed using Micro-CT imaging to obtain volumetric data without altering specimen integrity. The results revealed that the ultrasonic activation group exhibited the least amount of apical debris extrusion, followed by the sonic activation group, while conventional syringe irrigation produced the highest extrusion levels. Micro-CT visualization confirmed that activation techniques improved debris suspension and fluid exchange, thereby minimizing apical extrusion. These findings suggest that advanced irrigation activation systems enhance cleaning efficiency and safety by reducing debris displacement beyond the apical foramen.