Tonon, Caroline Coradi [UNESP]Paschoal, Marco AurélioCorreia, Marilia Ferreira [UNESP]Spolidorio, Denise Madalena Palomari [UNESP]Bagnato, Vanderlei SalvadorGiusti, Juçaíra Stella MartinsSantos-Pinto, Lourdes Aparecida Martins dos [UNESP]2015-08-062015-08-062015The Journal of Contemporary Dental Practice, v. 16, n. 1, p. 1-6, 2015.1526-3711http://hdl.handle.net/11449/125576Aim: The aim of this study was investigate the effect of photodynamic therapy (PDT) using curcumin (C) as a photosensitizing agent irradiated with an LED (L) in the blue wavelength as a light source on a standard and clinical isolate of Streptococcus mutans (S. mutans) in a planktonic suspension model. Materials and methods: Suspensions of both strains were divided into 4 groups as follows: absence of C and L (control group: C–L–), with C and without L (C group: C+L–), absence of C with L (L group: C–L+) and presence of C and L (PDT group: C+L+). Three different concentrations of curcumin (0.75 mg/ml, 1.5 mg/ml and 3 mg/ml) and three light fluences of studied light source (24, 48 and 72 J cm–2) were tested. Aliquots of each studied group was plated in BHI agar and submitted to colony forming units counting (CFU/ml) and the data transformed into logarithmical scale. Results: A high photoinactivation rate of more than 70% was verified to standard S. mutans strain submitted to PDT whereas the clinical isolate showed a lower sensitivity to all the associations of curcumin and LED. A slight bacterial reduction was verified to C+L– and C–L+, demonstrating no toxic effects to the isolated application of light and photosensitizer to both S. mutans strains tested. Conclusion: Photodynamic therapy using a combination of curcumin and blue LED presented a substantial antimicrobial effect on S. mutans standard strain in a planktonic suspension model with a less pronounced effect on its clinical isolate counterparts due to resistance to this alternative approach. Clinical significance: Alternative antimicrobial approaches, as photodynamic therapy, should be encouraged due to optimal results against cariogenic bacteria aiming to prevent or treat dental caries.1-6engStreptococcus mutansPhotochemotherapyCurcuminArtigo10.5005/jp-journals-10024-1626Acesso aberto29481620751701724947860249518663