Photodynamic therapy associated with conventional endodontic treatment in patients with antibiotic-resistant microflora: a preliminary report.
BACKGROUND
This study reports the antimicrobial effect of photodynamic therapy (PDT) combined with endodontic treatment in patients with necrotic pulp infected with microflora resistant to a previous antibiotic therapy.


METHODS
Thirty anterior teeth from 21 patients with periapical lesions that had been treated with conventional endodontic treatment and antibiotic therapy were selected. Microbiological samples were taken (1) after accessing the root canal, (2) after endodontic therapy, and (3) after PDT.


RESULTS
All the patients had at least 1 microorganism resistant to antibiotics. PDT used polyethylenimine chlorin(e6) as a photosensitizer and a diode laser as a light source (P = 40 mW, t = 4 minutes, E = 9.6 J). Endodontic therapy alone produced a significant reduction in numbers of microbial species but only 3 teeth were free of bacteria, whereas the combination of endodontic therapy with PDT eliminated all drug-resistant species and all teeth were bacteria-free.


CONCLUSIONS
The use of PDT added to conventional endodontic treatment leads to a further major reduction of microbial load. PDT is an efficient treatment to kill multi-drug resistant microorganisms.
Garcez
Aguinaldo S
AS
Centro de Pesquisa e Pós-Graduação São Leopoldo Mandic, Campinas, SP, Brazil. garcez.segundo@terra.com.br
Nuñez
Silvia C
SC
Hamblim
Michael R
MR
Suzuki
Hideo
H
Ribeiro
Martha S
MS
D000293:Adolescent; D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001421:Bacteria, Anaerobic / Q000187:drug effects / Q000528:radiation effects; D002735:Chlorophyllides; D015169:Colony Count, Microbial; D003131:Combined Modality Therapy; D003786:Dental Pulp Cavity / Q000382:microbiology* / Q000528:radiation effects; D003790:Dental Pulp Necrosis / Q000150:complications / Q000382:microbiology / Q000628:therapy*; D004203:Disinfection / Q000379:methods; D018432:Drug Resistance, Multiple / Q000528:radiation effects; D006801:Humans; D053685:Laser Therapy / Q000379:methods; D054023:Lasers, Semiconductor; D008875:Middle Aged; D010485:Periapical Periodontitis / Q000150:complications / Q000382:microbiology / Q000628:therapy*; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D011094:Polyethyleneimine / Q000627:therapeutic use; D011166:Porphyrins / Q000627:therapeutic use; D019233:Retreatment; D012390:Root Canal Therapy / Q000295:instrumentation / Q000379:methods*; D017211:Treatment Failure; D055815:Young Adult
D000900:Anti-Bacterial Agents; D002735:Chlorophyllides; D017319:Photosensitizing Agents; D011166:Porphyrins; C062985:phytochlorin; D011094:Polyethyleneimine