Method: Bacterial suspensions of S. mutans and L. acidophilus isolated (as single species) and combined (multspecies) were prepared and then evaluated. Four different groups were analyzed: L-D- (control group), L-D+ (drug group), L+D- (light group), and L+D+ (photodynamic therapy group). Two different concentrations of curcumin were tested (0.75 and 1.5 g/L) associated with a 5.7 J/cm2light emission diode.
Result: Significant decreases (p < 0.05) in the viability of S. mutans were only observed when the bacterial suspensions were exposed to both curcumin and light. Then, reductions in viability of up to 99.99% were observed when using 1.5 g/L of the photosensitizer. The susceptibility of L. acidophilus was considerably lower (21% and 37.6%) for both curcumin concentrations. Conclusion: , Photodynamic therapy was found to be effective in reducing S. mutans and L. acidophiluson planktonic cultures.
Conclusion: No significant reduction was found for L-D+, proving the absence of dark toxicity of the drug.
Research Support Foundation of São Paulo State (FAPESP), Studies and Projects Financier (FINEP), and Science and Technology Support Foundation of Pernambuco State (FACEPE).