13th World Congress for Laser Dentistry

26-28, April 2012

Barcelona, Spain

Meeting Abstract

Sponsors: World Federation for Laser Dentistry

-  Poster 100

TITLE: Antimicrobial photodynamic therapy in chronic osteomyelitis induced by Staphylococcus aureus: an in vitro and in vivo study.

AUTHORS: Carvalho FB, Reis Júnior JA, Assis PN, Barbosa AFS, Almeida PF, Pinheiro ALB.

Center of Biophotonics, School of Dentistry, Federal University of Bahia

SOURCE: Med Oral Patol Oral Cir Bucal. 2012 May 1;17(Supplement1):S248.

* doi:10.4317/medoral.17643748

http://dx.doi.org/10.4317/medoral.17643748

Abstract

Chronic osteomyelitis represents a major health problem due to its difficult treatment and increased morbidity. Antimicrobial photodynamic therapy (APT) by laser is a treatment in which the light emitted by a low power laser activates a specific photosensitizer triggering biochemical changes capable of killing bacteria. The aim of this study was to evaluate, both in vitro and in vivo, the effect of Antimicrobial Photodynamic Therapy on osteomyelitis. On the in vitro study a diode laser (λ660nm; 40mW; ø = 0.4 cm²; 5 and 10 J/cm²) and 5, 10 and 15μg/mL toluidine blue were tested and the best parameter chosen for the in vivo study. The results of the in vitro study showed that all APTs groups in the different concentrations reduced significantly (Anova test p<0.001) the amount of bacteria. The concentration of 5μg/mL was selected to perform the APT of infected by Staphylococcus aureus tibial bone defects in rats as it did not significantly caused bacterial death in vitro (p > 0.05). In vivo study the animals were killed immediately and after 30 days of treatment. APT group showed a significant average reduction on the counting of bacteria when compared with controls groups (p<0.05) in both experimental periods. Comparing the experimental periods, it was observed that after 30 days there was a significant reduction of microorganism. The Antimicrobial photodynamic therapy using toluidine blue was effective in reducing thestaphiloccocus aureus in both in vitro and in vivo studies.