title: Disinfection efficacy of photon-induced photoacoustic streaming on root canals infected with Enterococcus faecalis: an ex vivo study.
abstract: BACKGROUND
  In 2010, one of the authors proposed that lasers could be used to enhance the decontaminating action of sodium hypochlorite (NaOCl). The authors conducted a study to compare the disinfection efficacy of laser-activated irrigation (LAI) by using a photon-induced photoacoustic streaming (PIPS) tip with conventional irrigation and specifically LAI's ability to remove bacterial film formed on root canal walls.
  
  
  METHODS
  The authors shaped 26 human anterior teeth to a master apical file size of International Organization for Standardization 25/06 (size 25 tip and size .06 taper) and then sterilized the teeth, infected them with Enterococcus faecalis and incubated them for four weeks. The authors used two irrigation protocols. Group A received two cycles of 30 seconds each of 5 percent NaOCl laser activation and one cycle of 30 seconds with laser activation involving the use of 17 percent ethylenediaminetetraacetic acid (EDTA). The erbium:yttrium-aluminum-garnet (Er:YAG) laser's settings were 20 millijoules, 15 hertz, 50-microsecond pulse duration, and it had a 600-micrometer PIPS tip. Group B received two cycles of 30 seconds each of 5 percent NaOCl and 17 percent EDTA irrigation alone, delivered via a syringe with a 25-gauge needle.
  
  
  RESULTS
  The authors found that group A had significantly better disinfection compared with group B (P < .05). The results of cultures obtained after 48 hours showed that disinfection was maintained better in group A compared with group B (P < .0001). Scanning electron microscopic images showed absence of bacterial biofilm remaining after LAI using PIPS.
  
  
  CONCLUSIONS
  Er:YAG laser activation of 5 percent NaOCl and 17 percent EDTA was more effective than conventional irrigation for eradicating E. faecalis and preventing new bacterial growth ex vivo. Additional clinical studies are needed to clarify the effect on endodontic treatment outcomes.
  
  
  CONCLUSIONS
  PIPS appears to be effective in enhancing the effect of the irrigants commonly used in endodontics.
authors.affiliation: Dr. Olivi is an adjunct professor, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Olivi
authors.affiliation: Dr. DiVito is in private practice, Scottsdale, Ariz., and an adjunct professor, Department of Laser Dentistry, Arizona School of Dentistry and Oral Health, A.T. Still University, Mesa. Address correspondence to Dr. DiVito at Arizona Center for Laser Dentistry, 7900 E. Thompson Peak Parkway #101, Scottsdale, Ariz. 85255, e-mail edivito@azcld.com or info@pipsdocs.com.
authors.forename: Enrico
authors.initials: E
authors.lastname: DiVito
authors.affiliation: Dr. Peters is a cochair, Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco.
authors.forename: Ove
authors.initials: O
authors.lastname: Peters
authors.affiliation: Dr. Kaitsas is an assistant professor, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Vassilios
authors.initials: V
authors.lastname: Kaitsas
authors.affiliation: Dr. Angiero is a professor, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Angiero
authors.affiliation: Dr. Signore is an assistant professor, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Signore
authors.affiliation: Dr. Benedicenti is a professor, Department of Surgical Sciences and Integrated Diagnostics, University of Genoa, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Benedicenti
mesh_terms: D003786:Dental Pulp Cavity / Q000382:microbiology*; D004203:Disinfection / Q000379:methods*; D013293:Enterococcus faecalis / Q000302:isolation & purification*; D006801:Humans; D066298:In Vitro Techniques; D061088:Photoacoustic Techniques / Q000379:methods*; D017785:Photons
keywords: Decontamination; endodontics; irrigation; lasers