Comparative effects of photodynamic therapy mediated by curcumin on standard and clinical isolate of Streptococcus mutans

Aim: 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.

Avaliação comparativa in vivo da eficácia do óleo de melaleuca, clorexidina e listerine sobre streptococcus mutans e microrganismos totais na saliva

Objective: To compare the efficacy of the mouthwashes 0.12% chlorhexidine, Listerine, and 0.5% and 2% Melaleuca Alternifolia oil against the salivary levels of Streptococcus mutans and total microorganisms. Methods: This study was double-blind controlled and paired clinical assay. Twenty-six volunteers aged 21 to 35 years old were enrolled. At baseline, 1 mL of unstimulated saliva was collected from each subject, 1 and 15 min after mouthrinsing with the following solutions: sterile distilled water, 0.12% chlorhexidine digluconate, Listerine (©Johnson & Johnson do Brasil), 0.5% and 2% concentrations of Melaleuca Alternifolia (Sigma-Aldrich). The volunteers used all the evaluated mouthrinses with a 15-day interval between the solutions. Immediately after rinsing, saliva was collected and serial dilutions were performed, followed by plating in blood agar culture medium for growth of total microorganisms and SB-20 (Sucrose-Bacitracin agar) for growth of S. mutans, and incubation at 37 °C for 48 h in microaerophilia. After incubation, the number of colonies was counted and expressed as colony forming units (UFC/mL). Results: Chlorhexidine showed antimicrobial action by reducing total microorganisms and S. mutans, while the action of 0.5% Melaleuca Alternifolia was similar to that of distilled water. Listerine and 2% Melaleuca Alternifolia oil reduced total microbial counts by 11% and 9% respectively, and S. mutans by 20% and 11%. Conclusion: A single rinse with 0.12% chlorhexidine is effective in reducing the levels of total microorganisms and S. mutans present in saliva. Under the same testing conditions, Listerine and 0.5% and 2% Melaleuca Alternifolia oil presented lower efficacy than chlorhexidine.

The effect of chlorhexidine on plaque index and mutans streptococci in orthodontic patients: A pilot study

Aim: The purpose of this study was to assess chlorhexidine effects on plaque index and salivary levels of mutans streptococci (MS) when used as the immersion solution for removable orthodontic appliances and added to their acrylic resin composition. Methods: Forty-five patients (6 to 12 years old) were randomly assigned into three groups with 15 patients each. Group I (control)—without orthodontic appliances disinfection; Group II—removable orthodontic appliances which had been immersed in 0.12% chlorhexidine digluconate overnight (8 hours), and Group III—orthodontic appliances in which 0.12% chlorhexidine digluconate solution had been incorporated into their resin composition. Saliva was collected for quantification of MS and evaluation of plaque index was performed before and after installation of orthodontic appliance at 0, 2, 4, 6, 8, and 10 weeks. Data were analyzed by using analysis of variance. Results: Number of MS colonies in saliva and plaque index showed no statistically differences among groups at the different periods (p > 0.05). Conclusions: It could be concluded that chlorhexidine incorporation into the acrylic resin of removable orthodontic appliances at 0.12% concentration and immersion of the appliance into 0.12% chlorhexidine solution were not effective in reducing plaque index and the number of MS in saliva.

Is there difference of Streptococcus mutans count and adherence on amalgam and resin occlusal restorations? A blind clinical study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Recovering Streptococcus mutans over restorations by the tray technique: a randomized clinical study

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Streptococcus mutans adhesion and releasing of metallic ions in dental alloys

AIM: To evaluate the adherence of Streptococcus mutans to the surface of the amalgam and copper/aluminum alloy samples and also evaluate the release of metallic ions. METHODS: The prepared medium was changed every 72 h and analyzed by atomic absorption spectrophotometer. Samples were removed from the prepared medium at 15, 30, 48 and 60 days. RESULTS: The result shows that ions released were statistically different among all groups, and so were both biofilm and pits formation and the corrosion induced by the S. mutans in both types of samples. SEM observation of the samples immersed in the prepared medium with S. mutans showed adherence of microorganisms on the whole surface, in all groups. CONCLUSIONS: The S. mutans adhere to both amalgam and copper/aluminum alloy causing corrosion of those restorations. S. mutans produced a greater ions release in Cu/Al alloy; in amalgam, the ions release was not influenced by exposure to S. mutans.

Influência do tratamento expectante sobre propriedades acidogênicas e acidúricas de Streptococcus mutans e LLactobacillus acidophilus

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Streptococcus mutans-derived extracellular matrix in cariogenic oral biofilms

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de soluções fluoretadas contendo xilitol e sorbitol no número de estreptococos do grupo mutans na saliva de seres humanos

The objective of this study was to assess the effect of 0.05% sodium fluoride solutions containing 2.5% or 12.5% xylitol on the number of Streptococcus mutans in the human mouth. Fifty boys between 8 and 16 years of age participated in this double-blind crossover study. Of the original 50 boys, 33 finished the study. Participants were randomly divided into four groups. The following solutions were employed: placebo solution; 0.05% sodium fluoride solution; 0.05% sodium fluoride + 2.5% xylitol + 2% sorbitol; 0.05% sodium fluoride + 12.5% xylitol + 2% sorbitol. Each solution was used for a 28-day period (20 mL/day, twice a day), with a 10-day washout period between solutions. There were no significant differences (P = 0.32) between the two xylitol-containing solutions (2.5% vs. 12.5%) concerning the number of Streptococcus mutans. However, there was a significant difference between these two xylitol-containing solutions and the sodium fluoride and placebo solutions (P < 0.001). Our results suggest that the 0.05% sodium fluoride solutions containing either 2.5% or 12.5% xylitol caused a significant reduction in the number of Streptococcus mutans.

In vitro reduction of Streptococcus mutans biofilm on silver nanoparticle-modified resin composite

Introduction: Currently, new methods to reduce biofilm formation on biomaterials are very studied, for example the use of silver nanoparticles, which were bactericidal. However, there are few studies investigating the benefits of these particles in dental restorative materials. Objective: This study aimed to compare in vitro the Streptococcus mutans biofilm formation on conventional light-cured composite resin with that on experimental light-cured composite resin, modified with silver nanoparticles. Material and methods: Discs were produced with either conventional resin (control group) and resin modified with different concentrations of silver nanoparticles, 0.1%, 0.3% and 0.6 % wt. (groups 1, 2 and 3, respectively). The samples were incubated in bacterial suspension (S. mutans) enriched with 20% sucrose to promote biofilm growth on the surfaces. Incubation times were 1, 4 and 7 days. After each period, adherent biofilms were disaggregated by ultrasound. Then, the numbers of viable cells recovered from the biofilms were counted through the serial dilution method. A morphological analysis of biofilm was also performed by Scanning Electron Microscopy. The data were subjected to Anova and Tukey’s test (α = 0.05). Results: The number of viable cells was statistically lower in groups 2 and 3 than in group 1 and control group, after the three incubation periods, without statistical difference between groups 2 and 3. The number of viable cells was statistically lower in group 1 than in control group, after 4 and 7 days of incubation. Conclusion: Resins modified with silver presented reduction of S. mutans biofilm on their surfaces, according to the conditions of this study.

Efeito do tirosol sobre biofilmes de Streptococcus mutans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Papel de cepas de Streptococcus mutans e Bifidobacterium spp. na etiologia ou proteção contra doenças bucais

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos das cepas probioticas de Lactobacillus acidophilus ATCC 4356, Lactobacillus rhamnosus ATCC 1465 e ATCC 7469 sobre o crescimento planctonico e formação de biofilme de Streptococcus mutans UA 159

Pós-graduação em Biopatologia Bucal - ICT

Inativação fotodinâmica em biofilme de Streptococcus mutans sobre bráquetes metálicos e cerâmicos: um estudo in vitro

Pós-graduação em Odontologia Restauradora - ICT

Efeito do farnesol sobre fatores de virulência de Candida albicans e Streptococcus mutans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)