In vitro effect of photodynamic therapy on aggregatibacter actinomycetemcomitans and Streptococcus sanguinis.
New periodontal disease treatments are needed to prevent infection progression. Photodynamic therapy (PDT) is one of the greatest pledges for this purpose. It involves the use of light of specific wavelength to activate a nontoxic photosensitizing agent in the presence of oxygen for eradication of target cells, and can be used for photokilling of microorganisms. This study evaluated in vitro the photodynamic effect of 0.01% toluidine blue-O (TBO) in combination with an AlGaInP diode laser light source on Aggregatibacter actinomycetemcomitans (A.a.) and Streptococcus sanguinis (S.s.). Suspensions (2 mL) containing A.a. and S.s. at 1.5 x 108 CFU/mL concentration were prepared and divided into 3 groups: Control group (no treatment), Dye group (inoculum and TBO for 5 min) and Dye/Laser group (inoculum, TBO for 5 min and laser for 3 min). Next, a dilution for subsequent subculture in 20 mL of Trypic Soy Agar (A.a) and Brucella Agar (S.s.) in Petri dishes (Pourplate Method) was done. Incubation of A.a. in microaerophilia and S.s. in aerobiosis at 35oC for 48 h was performed for subsequent visual counting of CFU/mL. Data were analyzed by one-way ANOVA and Tukey's HSD test at 5% significance level. For both strains, the control group showed a significantly higher (p<0.05) bacterial growth (1.5 x 108 CFU/mL), while the Dye group presented no significant reduction (p>0.05) in the CFU counts. The Dye/Laser group presented a significant decrease in the CFU counts (p<0.05) compared with the Control group (61.53% for A.a. and 84.32% for S.s.). It may be concluded that PDT was effective in reducing the numbers of A.a. and S.s. in vitro.
Department of Prosthetic and Restorative Dentistry, Dental School, Federal University of Mato Grosso do Sul, Campo Grande, MS, Brazil. fabianodlm@hotmail.com
Fabiano Dalla Lana
FD
Mattiello
Alan Augusto Kalife
AA
Coelho
Odair Pimentel
OP
Martins
Rodrigo Dalla Lana
RD
Mattiello
José Peixoto
JP
Ferrão Júnior
D016976:Aggregatibacter actinomycetemcomitans / Q000187:drug effects* / Q000254:growth & development; D058491:Bacterial Load / Q000187:drug effects; D001431:Bacteriological Techniques; D006801:Humans; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D050296:Microbial Viability / Q000187:drug effects; D010510:Periodontal Diseases / Q000188:drug therapy / Q000382:microbiology; D010778:Photochemotherapy / Q000379:methods*; D017319:Photosensitizing Agents / Q000627:therapeutic use; D013298:Streptococcus sanguis / Q000187:drug effects* / Q000254:growth & development; D013997:Time Factors; D014048:Tolonium Chloride / Q000627:therapeutic use
D017319:Photosensitizing Agents; D014048:Tolonium Chloride