title: Effects of low-level laser therapy combined with toluidine blue on polysaccharides and biofilm of Streptococcus mutans.
abstract: The aim of this study was to evaluate the effect of a low-level laser therapy in combination with toluidine blue on polysaccharides and biofilm of Streptococcus mutans. S. mutans biofilms were formed on acrylic resin blocks. These biofilms were exposed eight times/day to 10 % sucrose, and two times/day, they were subjected to one of the following treatments: G1, 0.9 % NaCl as a negative control; G2, 0.12 % chlorhexidine digluconate (CHX) as a positive antibacterial control; and G3 and G4 antimicrobial photodynamic therapy (aPDT) combined with toluidine blue using dosages of 320 and 640 J/cm(2), respectively. The experiment was performed in triplicate. The biofilm formed on each block was collected for determination of the viable bacteria and concentration of insoluble extracellular polysaccharides (IEPS) and intracellular polysaccharides (IPS). CHX and aPDT treatments were able to inhibit bacterial growth in comparison with negative control (p < 0.05). The aPDT treatment reduced the number of viable bacteria formed in the S. mutans biofilm, in a dose-dependent manner (p < 0.05). The concentration of IEPS and IPS in the biofilms formed in presence of aPDT did not differ each other or in comparison to CHX (p > 0.05). The results suggest that low-level laser therapy presents effects on biofilm bacteria viability and in polysaccharides concentration.
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, 14040-904, Brazil.
authors.forename: S S
authors.initials: SS
authors.lastname: de Sousa Farias
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, 14040-904, Brazil.
authors.forename: M A
authors.initials: MA
authors.lastname: Nemezio
authors.affiliation: Department of Restorative Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, 14040-904, Brazil.
authors.forename: S A M
authors.initials: SA
authors.lastname: Corona
authors.affiliation: Department of Physics and Chemistry, School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, 14040-903, Brazil. airescp@fcfrp.usp.br.
authors.forename: C P
authors.initials: CP
authors.lastname: Aires
authors.affiliation: Department of Pediatric Dentistry, School of Dentistry of Ribeirão Preto, University of São Paulo, Avenida do Café s/n, Ribeirão Preto, SP, 14040-904, Brazil.
authors.forename: M C
authors.initials: MC
authors.lastname: Borsatto
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002710:Chlorhexidine / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D028022:Low-Level Light Therapy / Q000379:methods*; D050296:Microbial Viability / Q000187:drug effects; D010778:Photochemotherapy / Q000379:methods*; D011134:Polysaccharides; D013295:Streptococcus mutans / Q000187:drug effects*; D014048:Tolonium Chloride / Q000494:pharmacology*
chemical_list: D000900:Anti-Bacterial Agents; D011134:Polysaccharides; D014048:Tolonium Chloride; C010882:chlorhexidine gluconate; D002710:Chlorhexidine
keywords: Antimicrobial photodynamic therapy; Biofilms; Diode laser; Polysaccharides; Streptococcus mutans