Reduced methicillin-resistant Staphylococcus aureus biofilm formation in bone cavities by photodynamic therapy

•PDT reduced significantly the MRSA biofilms of bone lesions in bovine bone.•Spectral fluorescence after the PDT and LED groups showed reduction of the MRSA biofilms.•The PDT protocol studied is the basis for studies of the treatment of these lesions in the clinic. Photodynamic Therapy (PDT) is a promising alternative for the treatment of infectious bone lesions in the oral cavity. The objective of this study was to evaluate the antimicrobial effectiveness of PDT using blue LED associated with curcumin in methicillin-resistant Staphylococcus aureus biofilms (MRSA) in bovine bone cavities by fluorescence spectroscopy. Standardized suspensions of MRSA culture were inoculated into bone lesions to form biofilm. Forty bone species were distributed in three distinct groups: L-C- (control); L + C- (LED for 5 min); L-C+ (curcumin incubation for 5 min) and L + C+ (PDT). Aliquots of 100 μL were collected from the bone cavities after the treatments and were cultived in BHI for 24 h at 36 °C ± 1 and bacterial colonies counting were performed. Statistical analysis were performed using the paired t-test and analysis of variance (ANOVA) for the variables studied. Results: The control and PDT groups presented statistically significant differences (p