Canal blockage and debris extrusion with eight preparation techniques

Area of Science:

• Endodontics
• Dental Materials Science

Background:

• Root canal preparation aims to clean and shape the root canal system.
• Ineffective cleaning can lead to procedural complications like canal blockage and apical extrusion of debris.

Purpose of the Study:

• To compare the incidence of canal blockages and apical extrusion of dentin debris among eight different root canal preparation techniques.
• To identify techniques that minimize procedural complications during root canal shaping.

Main Methods:

• 208 root canals from extracted human teeth were shaped using one of eight techniques by a single operator.
• Techniques included standardized, stepback variations, double-flare, stepdown, crown-down pressureless, and balanced force.
• Canal blockages were recorded, and apically extruded dentin debris was collected and weighed.

Main Results:

• Significant differences in canal blockages were observed (p < 0.001), with stepback techniques causing the most and balanced force the least.
• Apical extrusion occurred in most roots (169/208), with no significant difference in incidence among techniques.
• Dentin debris weight varied significantly (p < 0.05), with stepback techniques extruding more debris than balanced force or crown-down pressureless.

Conclusions:

• Root canal preparation techniques employing a filing (linear) motion resulted in significantly more canal blockages.
• These filing techniques also led to significantly greater apical extrusion of dentin debris.
• The balanced force technique demonstrated the lowest incidence of blockages and minimal apical debris extrusion.