Penetration depth of a dye marker into dentine using a novel hydrodynamic system (RinsEndo®)

Abstract Aim To investigate the efficiency of a hydrodynamic irrigation system compared with conventional cleansing techniques in root canals. Methodology Forty‐five freshly extracted single‐rooted teeth were de‐coronated and their root canals were enlarged to size 30 at the apex. The teeth were randomly divided into three groups ( n = 15) for the final rinsing sequence using 2% NaOCl plus acid fuchsin: group I: static application of irrigant, 3 min; group II: flushing with a syringe; 5‐mL NaOCl, 1 min; group III: RinsEndo ® ‐system; 5‐mL NaOCl, 50 s. Apical extrusion was documented photographically. The roots were sectioned at 2, 4, 6 and 8 mm from their apices and the penetration depths of dye into dentine measured, using a stereomicroscope. Wilcoxon's test and Pearson's chi‐squared test were employed to prove statistic relevance. Results Greater dye penetration depth into the dentinal tubules was achieved when employing hydrodynamic rinsing procedures. Using this technique, 23% of the specimens were penetrated for more than 50% of their dentine thickness, whereas the results for flushing with a syringe were 12% (static application, 7%). No penetration of dentine occurred in 63% of specimens with static application, 39% flushing with a syringe and 15% using the hydrodynamic system ( P < 0.05 Pearson's chi‐squared test). Apical extrusion occurred more frequently after hydrodynamic rinsing (extruded specimens: RinsEndo ® = 80%; static application/flushing with a syringe = 13%; P < 0.05 Pearson's chi‐squared test). Conclusions Hydrodynamic rinsing demonstrated an improvement over conventional methods in terms of dentine penetration of a dye marker. A higher risk of apical extrusion with the RinsEndo ® ‐system was evident.