title: Penetration depth of a dye marker into dentine using a novel hydrodynamic system (RinsEndo).
abstract: OBJECTIVE
  To investigate the efficiency of a hydrodynamic irrigation system compared with conventional cleansing techniques in root canals.
  
  
  METHODS
  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.
authors.affiliation: Department of Periodontology, Operative and Preventive Dentistry, University Dental Clinic, Bonn, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Hauser
authors.forename: A
authors.initials: A
authors.lastname: Braun
authors.forename: M
authors.initials: M
authors.lastname: Frentzen
mesh_terms: D016009:Chi-Square Distribution; D004396:Coloring Agents / Q000737:chemistry*; D003804:Dentin / Q000648:ultrastructure; D006801:Humans; D012388:Root Canal Irrigants / Q000737:chemistry*; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*; D012973:Sodium Hypochlorite / Q000737:chemistry / Q000627:therapeutic use; D018709:Statistics, Nonparametric; D007507:Therapeutic Irrigation / Q000295:instrumentation / Q000379:methods*
chemical_list: D004396:Coloring Agents; D012388:Root Canal Irrigants; D012973:Sodium Hypochlorite