title: Antimicrobial photodynamic therapy combined with conventional endodontic treatment to eliminate root canal biofilm infection.
abstract: OBJECTIVE
  To compare the effectiveness of antimicrobial photodynamic therapy (PDT), standard endodontic treatment and the combined treatment to eliminate bacterial biofilms present in infected root canals.
  
  
  METHODS
  Ten single-rooted freshly extracted human teeth were inoculated with stable bioluminescent Gram-negative bacteria, Proteus mirabilis and Pseudomonas aeruginosa to form 3-day biofilms in prepared root canals. Bioluminescence imaging was used to serially quantify bacterial burdens. PDT employed a conjugate between polyethylenimine and chlorin(e6) as the photosensitizer (PS) and 660-nm diode laser light delivered into the root canal via a 200-micro fiber, and this was compared and combined with standard endodontic treatment using mechanical debridement and antiseptic irrigation.
  
  
  RESULTS
  Endodontic therapy alone reduced bacterial bioluminescence by 90% while PDT alone reduced bioluminescence by 95%. The combination reduced bioluminescence by >98%, and importantly the bacterial regrowth observed 24 hours after treatment was much less for the combination (P<0.0005) than for either single treatment.
  
  
  CONCLUSIONS
  Bioluminescence imaging is an efficient way to monitor endodontic therapy. Antimicrobial PDT may have a role to play in optimized endodontic therapy.
authors.affiliation: Center for Lasers and Applications, IPEN-CNEN/SP, São Paulo, SP, Brazil.
authors.forename: Aguinaldo S
authors.initials: AS
authors.lastname: Garcez
authors.forename: Martha S
authors.initials: MS
authors.lastname: Ribeiro
authors.forename: George P
authors.initials: GP
authors.lastname: Tegos
authors.forename: Silvia C
authors.initials: SC
authors.lastname: Núñez
authors.forename: Antonio O C
authors.initials: AO
authors.lastname: Jorge
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hamblin
mesh_terms: D000890:Anti-Infective Agents / Q000627:therapeutic use*; D018441:Biofilms / Q000187:drug effects; D002735:Chlorophyllides; D003786:Dental Pulp Cavity / Q000187:drug effects* / Q000382:microbiology*; D003788:Dental Pulp Diseases / Q000628:therapy*; D004708:Endodontics / Q000379:methods; D006801:Humans; D049449:Luminescence; D010778:Photochemotherapy; D011094:Polyethyleneimine / Q000627:therapeutic use; D011166:Porphyrins / Q000627:therapeutic use; D011512:Proteus Infections / Q000188:drug therapy; D011513:Proteus mirabilis / Q000502:physiology; D011552:Pseudomonas Infections / Q000188:drug therapy; D011550:Pseudomonas aeruginosa / Q000502:physiology
chemical_list: D000890:Anti-Infective Agents; D002735:Chlorophyllides; D011166:Porphyrins; C062985:phytochlorin; D011094:Polyethyleneimine