title: Antibacterial Efficacy of a New Sonic Irrigation Device for Root Canal Disinfection.
abstract: BACKGROUND
  Passive ultrasonic irrigation (PUI) is the most widespread method used to activate irrigation solutions. Concerns have been raised that PUI is less effective in curved root canals and is not passive at all. Our aim was to compare a novel passive sonic irrigation (PSI) device (6000 Hz) with PUI and manual irrigation (MI) with respect to their efficiency in removing different endodontic microorganisms from curved and straight root canals.
  
  
  METHODS
  We performed 2 experiments as follows. In a 3-day infection model, we included 8 groups of single or dual microbial species that were rinsed with 0.9% sodium chloride using PSI, PUI, or MI. Colony-forming units (CFUs) were counted after incubation, and log10transformations were performed for statistical comparisons. In a 21-d infection model, we tested the same irrigation protocols on 4 groups of microorganisms and used 1.5% sodium hypochlorite as an irrigant. Infection control samples were taken at day 0, 3, 5, and 7 after treatment and were subsequently reincubated.
  
  
  RESULTS
  Using sodium chloride as an irrigant, the amount of reduction in CFUs compared with the negative control was approximately 3 log10units for PSI at 6000 Hz, 2 log10units for PUI, and 1 log10unit for MI. PSI reduced the microorganism CFUs significantly better than PUI. Using sodium hypochlorite led to a significant reduction in microorganism CFUs even with MI. After 3 days, compared with MI, microorganism regrowth significantly reduced after PSI and PUI treatment, but in these groups, in at least half of the samples, microorganisms were detectable after 7 days.
  
  
  CONCLUSIONS
  PSI at 6000 Hz might be at least equal to PUI with respect to reduction of the microbial load in curved and straight root canals.
authors: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland. Electronic address: klaus.neuhaus@zmk.unibe.ch.
authors: Klaus W
authors: KW
authors: Neuhaus
authors: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors: Melanie
authors: M
authors: Liebi
authors: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors: Simone
authors: S
authors: Stauffacher
authors: Laboratory of Oral Microbiology, Department of Periodontology, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors: Sigrun
authors: S
authors: Eick
authors: Department of Preventive, Restorative and Pediatric Dentistry, School of Dental Medicine, University of Bern, Bern, Switzerland.
authors: Adrian
authors: A
authors: Lussi
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001419:Bacteria / Q000187:drug effects; D003786:Dental Pulp Cavity / Q000187:drug effects / Q000382:microbiology*; D004203:Disinfection / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000627:therapeutic use*; D018915:Root Canal Preparation / Q000295:instrumentation* / Q000379:methods; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods; D012965:Sodium Chloride / Q000494:pharmacology; D012973:Sodium Hypochlorite / Q000627:therapeutic use; D013234:Stem Cells; D007507:Therapeutic Irrigation / Q000295:instrumentation* / Q000379:methods; D014464:Ultrasonic Therapy / Q000295:instrumentation / Q000379:methods; D014465:Ultrasonics / Q000295:instrumentation*
chemical_list: D000900:Anti-Bacterial Agents; D012388:Root Canal Irrigants; D012965:Sodium Chloride; D012973:Sodium Hypochlorite
keywords: Disinfection; oral bacteria; root canal; sonic irrigation; ultrasonic irrigation