07 December 2022

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What can cause the extrusion of debris beyond the apex in root canal therapies?

Simona Chirico

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After a root canal treatment, the onset of postoperative pain is strictly dependent on factors related to the patient, such as the presence of preoperative pain, occlusal trauma and the virulence of the microorganisms that caused the pathology and factors related to the operator.

During root canal shaping the operator can inadvertently push fragments of dentin, pulp tissue, microorganisms and their by-products and irritants beyond the apical foramen into the periapical tissues. This can happen regardless of the instruments and technique used, generating apical extrusion debris. Since rotary file systems have different cross sections, groove depths, kinematics and alloy properties, the amount of DAE can vary accordingly.

In an experimental in vitro study, the authors investigated the influence of five different root canal shaping systems on apical debris extrusion using two different irrigation protocols. In the study, researchers assessed 150 mandibular permanent first molars divided into two groups and 10 subgroups.

• Group 1: mesial root canals were irrigated with 10 ml of distilled water
• Group 2: mesial root canals were irrigated with five ml of distilled water

Each of the two groups was divided into five subgroups according to the type of instrumentation used:

• Subgroup A: Canals were shaped with One Reci (MicroMega), exploiting the reciprocating movement
• Subgroup B: Canals were contoured with WaveOne Gold Primary (Dentsply Sirona, York, PA) with reciprocating motion
• Subgroup C: Canals were contoured with ProTaper Next (Dentsply Sirona) with reciprocating motion
• Subgroup D: Canals were shaped with One Curve (MicroMega) using continuous rotational motion
• Subgroup E: The canals were shaped with ProTaper Next in continuous rotation.

Results

If the same instrumentation technique was used, the 10mL irrigated groups showed statistically less debris extrusion than the five mL irrigated groups. The subgroups One Reci and One Curve, in both irrigation groups, produced statistically less than the remaining subgroups.

Conclusions

The cross section of the instrument can determine the amount of apical extrusion debris. The volume of irrigation used during the shaping procedure can also affect this amount.

For additional information: Apically Extruded Debris in Curved Root Canals Using a New Reciprocating Single-File Shaping System

Naji Kharouf, Eugenio Pedullà, Walid Nehme, Kadour Akarma, Adrien Mercey, Catherine Isabelle Gros, Youssef Haikel, Davide Mancino. "Apically Extruded Debris in Curved Root Canals Using a New Reciprocating Single-File Shaping System." J Endod. 2022 Jan;48(1):117-122. doi: 10.1016/j.joen.2021.10.002. Epub 2021 Oct 23.