JOE SET 2010 - Photodynamic Therapy Associated with Conventional Endodontic Treatment in Patients with Antibiotic-resistant Microflora: A Preliminary Report

Photodynamic Therapy Associated with Conventional Endodontic Treatment in Patients with Antibiotic-resistant Microflora: A Preliminary Report

Aguinaldo S. Garcez, PhD,* Silvia C. Nun ̃ez, PhD,† Michael R. Hamblim, PhD,‡§k Hideo Suzuki,* and Martha S. Ribeiro, PhD¶

Introduction:

 This study reports the antimicrobial effect of photodynamic therapy (PDT) combined with endodontic treatment in patients with necrotic pulp in- fected 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 = 4minutes, 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: 

Our results suggest that the use of PDT as an adjuvant to conven- tional endodontic treatment leads to a significant further reduction of bacterial load and is effective against multi-drug resistant bacteria. PDT offers an efficient means of destroying multi-drug resistant bacteria remaining inside the root canal system after using conventional endodontic chemomechanical therapy.

 (J Endod 2010;36:1463–1466)