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PURPOSE: This study aimed to investigate the efficiency of antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans biofilm in the oral cavity using the photosensitizer chloroaluminum phthalocyanine encapsulated in chitosan nanoparticles (ClAlPc/Ch) at three preirradiation times. METHODS: Biofilms of Streptococcus mutans strains (ATCC 25,175) were cultivated on bovine tooth blocks and exposed to a 10% sucrose solution three times a day for 1 min over three consecutive days. The samples were randomly distributed into five treatment groups (n = 5): (I) aPDT with ClAlPc/Ch with a preirradiation time of 5 min (F5), (II) aPDT with ClAlPc/Ch with a preirradiation time of 15 min (F15), (III) aPDT with ClAlPc/Ch with a preirradiation time of 30 min (F30), (IV) 0.12% chlorhexidine digluconate (CHX), and (V) 0.9% saline solution (NaCl). After treatment, the S. mutans biofilms formed on each specimen were collected to determine the number of viable bacteria (colony-forming units (CFU)/mL). Data were analyzed for normality using the Shapiro-Wilk test and the analysis of variance (ANOVA) and Tukey HSD tests to analyze the number of viable bacteria (α = 0.05). RESULTS: The one-way ANOVA showed a difference between the groups (p = 0.0003), and the Tukey HSD posttest showed that CHX had the highest microbial reduction of S. mutans, not statistically different from the F5 and F15 groups, whereas the NaCl group had the lowest microbial reduction statistically similar to the F30 group. CONCLUSION: The results demonstrate that aPDT mediated by ClAlPc/Ch when used at preirradiation times of 5-15 min can be an effective approach in controlling cariogenic biofilm of S. mutans, being an alternative to 0.12% CHX.
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Biopelículas , Quitosano , Nanopartículas , Fotoquimioterapia , Fármacos Fotosensibilizantes , Streptococcus mutans , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/efectos de la radiación , Streptococcus mutans/fisiología , Fotoquimioterapia/métodos , Quitosano/farmacología , Quitosano/química , Nanopartículas/química , Biopelículas/efectos de los fármacos , Biopelículas/efectos de la radiación , Animales , Bovinos , Fármacos Fotosensibilizantes/farmacología , Técnicas In Vitro , Indoles/farmacología , Boca/microbiología , Clorhexidina/farmacología , Clorhexidina/análogos & derivados , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Compuestos OrganometálicosRESUMEN
BACKGROUND: Periodontal disease is the leading cause of tooth loss, and an association between periodontal disease and non-oral systemic diseases has been shown. Formation of biofilm by periodontal pathogens such as Fusobacterium nucleatum, Porphyromonas gingivalis, and Streptococcus mutans and their resistance to antimicrobial agents are at the root of persistent and chronic bacterial infections. METHODS: The bactericidal effect of far-ultraviolet (F-UV) light irradiation at 222 nm on periodontal bacteria was assessed qualitatively and quantitatively. The effect of biofilm disruption by F-UV light on periodontal bacteria was examined by crystal violet staining, and the morphologic changes of the biofilm after F-UV irradiation were explored by confocal laser microscopy and scanning electron microscopy. We developed a thin fiber-type 222 nm F-UV irradiator and studied its safety and effect of reducing bacteria in rodent models. RESULTS: F-UV light at 222 nm had a bactericidal effect on F. nucleatum, P. gingivalis, and S. mutans. Irradiation with F-UV light reduced the biofilm formed by the bacteria and sterilized them from within. Confocal laser microscopy showed a clear reduction in biofilm thickness, and scanning electron microscopy confirmed disintegration of the biofilm architecture. F-UV irradiation was less damaging to DNA and less cytotoxic than deep-ultraviolet light, and it reduced bacterial counts on the tooth surface. CONCLUSION: F-UV irradiation has the potential to destroy biofilm and act as a bactericide against pathogenic bacteria in the biofilm.
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Biopelículas , Fusobacterium nucleatum , Periodontitis , Porphyromonas gingivalis , Streptococcus mutans , Rayos Ultravioleta , Biopelículas/efectos de los fármacos , Biopelículas/efectos de la radiación , Porphyromonas gingivalis/efectos de los fármacos , Porphyromonas gingivalis/efectos de la radiación , Fusobacterium nucleatum/efectos de los fármacos , Fusobacterium nucleatum/efectos de la radiación , Animales , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/efectos de la radiación , Streptococcus mutans/fisiología , Periodontitis/microbiología , Microscopía Confocal , Microscopía Electrónica de Rastreo , Ratones , Viabilidad Microbiana/efectos de la radiación , Viabilidad Microbiana/efectos de los fármacos , HumanosRESUMEN
OBJECTIVES: To assess the growth of a multispecies biofilm on root canal dentin under different radiotherapy regimens. MATERIALS AND METHODS: Sixty-three human root dentin cylinders were distributed into six groups. In three groups, no biofilm was formed (n = 3): NoRT) non-irradiated dentin; RT55) 55 Gy; and RT70) 70 Gy. In the other three groups (n = 18), a 21-day multispecies biofilm (Enterococcus faecalis, Streptococcus mutans, and Candida albicans) was formed in the canal: NoRT + Bio) non-irradiated + biofilm; RT55 + Bio) 55 Gy + biofilm; and RT70 + Bio) 70 Gy + biofilm. The biofilm was quantified (CFUs/mL). Biofilm microstructure was assessed under SEM. Microbial penetration into dentinal tubules was assessed under CLSM. For the biofilm biomass and dentin microhardness pre- and after biofilm growth assessments, 45 bovine dentin specimens were distributed into three groups (n = 15): NoRT) non-irradiated + biofilm; RT55 + Bio) 55 Gy + biofilm; and RT70 + Bio) 70 Gy + biofilm. RESULTS: Irradiated specimens (70 Gy) had higher quantity of microorganisms than non-irradiated (p = .010). There was gradual increase in biofilm biomass from non-irradiated to 55 Gy and 70 Gy (p < .001). Irradiated specimens had greater reduction in microhardness after biofilm growth. Irradiated dentin led to the growth of a more complex and irregular biofilm. There was microbial penetration into the dentinal tubules, regardless of the radiation regimen. CONCLUSION: Radiotherapy increased the number of microorganisms and biofilm biomass and reduced dentin microhardness. Microbial penetration into dentinal tubules was noticeable. CLINICAL RELEVANCE: Cumulative and potentially irreversible side effects of radiotherapy affect biofilm growth on root dentin. These changes could compromise the success of endodontic treatment in oncological patients undergoing head and neck radiotherapy.
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Biopelículas , Candida albicans , Cavidad Pulpar , Dentina , Enterococcus faecalis , Streptococcus mutans , Biopelículas/efectos de la radiación , Dentina/microbiología , Dentina/efectos de la radiación , Humanos , Cavidad Pulpar/microbiología , Cavidad Pulpar/efectos de la radiación , Candida albicans/efectos de la radiación , Animales , Enterococcus faecalis/efectos de la radiación , Streptococcus mutans/efectos de la radiación , Bovinos , Microscopía Electrónica de Rastreo , Dureza , Microscopía Confocal , Dosificación RadioterapéuticaRESUMEN
BACKGROUND: This study was conducted to investigate the efficiency of periodontal ligament (PDL) stem cell-derived exosome-loaded Emodin (Emo@PDL-Exo) in antimicrobial photodynamic therapy (aPDT) on Streptococcus mutans and Lactobacillus acidophilus as the cariogenic bacteria. MATERIALS AND METHODS: After isolating and characterizing PDL-Exo, the study proceeded to prepare and verify the presence of Emo@PDL-Exo. The antimicrobial effect, anti-biofilm activity, and anti-metabolic potency of Emo, PDL-Exo, and Emo@PDL-Exo were then evaluated with and without irradiation of blue laser at a wavelength of 405 ± 10 nm with an output intensity of 150 mW/cm2 for a duration of 60 s. In addition, the study assessed the binding affinity of Emodin with GtfB and SlpA proteins using in silico molecular docking. Eventually, the study examined the generation of endogenous reactive oxygen species (ROS) and changes in the gene expression levels of gelE and sprE. RESULTS: The study found that using Emo@PDL-Exo-mediated aPDT resulted in a significant decrease in L. acidophilus and S. mutans by 4.90 ± 0.36 and 5.07 log10 CFU/mL, respectively (P < 0.05). The study found that using Emo@PDL-Exo for aPDT significantly reduced L. acidophilus and S. mutans biofilms by 44.7% and 50.4%, respectively, compared to untreated biofilms in the control group (P < 0.05). Additionally, the metabolic activity of L. acidophilus and S. mutans decreased by 58.3% and 71.2%, respectively (P < 0.05). The molecular docking analysis showed strong binding affinities of Emodin with SlpA and GtfB proteins, with docking scores of -7.4 and -8.2 kcal/mol, respectively. The study also found that the aPDT using Emo@PDL-Exo group resulted in the most significant reduction in gene expression of slpA and gtfB, with a decrease of 4.2- and 5.6-folds, respectively, compared to the control group (P < 0.05), likely due to the increased generation of endogenous ROS. DISCUSSION: The study showed that aPDT using Emo@PDL-Exo can effectively reduce the cell viability, biofilm activity, and metabolic potency of S. mutans and L. acidophilus. aPDT also significantly reduced the expression levels of gtfB and slpA mRNA due to the increased endogenous ROS generation. The findings suggest that Emo@PDL-Exo-mediated aPDT could be a promising antimicrobial approach against cariogenic microorganisms.
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Antiinfecciosos , Emodina , Exosomas , Fotoquimioterapia , Humanos , Fármacos Fotosensibilizantes/farmacología , Fármacos Fotosensibilizantes/uso terapéutico , Emodina/farmacología , Especies Reactivas de Oxígeno , Simulación del Acoplamiento Molecular , Ligamento Periodontal , Fotoquimioterapia/métodos , Streptococcus mutans/efectos de la radiación , Biopelículas , Células MadreRESUMEN
This study aimed to investigate the photodynamic effects of curcumin, nanomicelle curcumin, and erythrosine on Lactobacillus casei (L. casei). Various concentrations of curcumin (1.5 g/L, 3 g/L), nano-curcumin (3 g/L), and erythrosine (100 µM/L, 250 µM/L) were tested either alone or combined with light irradiation (PDT effect) against L. casei in planktonic and biofilm cultures. The light was emitted from a light-emitting diode (LED) with a central wavelength of 450 nm. A 0.12% chlorhexidine digluconate (CHX) solution served as the positive control, and a solution containing neither photosensitizer nor light was the negative control group. The number of viable microorganisms was determined using serial dilution. There was a significant difference in the viability of L. casei in both planktonic and biofilm forms (P < 0.05). In the planktonic culture, the antibacterial effects of CHX and PDT groups with curcumin 3 g/L and erythrosine 250 µM/L were significantly greater than the other groups (P < 0.05). For L. casei biofilms, the greatest toxic effects were observed in CHX and PDT groups with curcumin 3 g/L, erythrosine 250 µmol/L, erythrosine 100 µmol/L, and nanomicelle curcumin 3 g/L, with a significant difference to other groups (P < 0.05). The antibacterial effects of all photosensitizers (except erythrosine 250 µmol/L at planktonic culture) enhanced significantly when combined with light irradiation (P < 0.05). PDT with curcumin 3 g/L or erythrosine 250 µmol/L produced comparable results to CHX against L. casei at both planktonic and biofilm cultures. Alternatively, PDT with erythrosine 100 µmol/L or nanomicelle curcumin 3 g/L could be suggested to kill L. casei biofilms.
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Antiinfecciosos , Curcumina , Lacticaseibacillus casei , Fotoquimioterapia , Eritrosina/farmacología , Fotoquimioterapia/métodos , Curcumina/farmacología , Streptococcus mutans/efectos de la radiación , Fármacos Fotosensibilizantes/farmacología , Antiinfecciosos/farmacología , Biopelículas , Antibacterianos/farmacologíaRESUMEN
BACKGROUND: The aim of this study was to evaluate the inactivation potency of riboflavin and curcumin plus blue diode laser against Streptococcus mutans with different power densities. MATERIALS AND METHODS: In this in vitro study, standard-strain S. mutans was exposed to curcumin and riboflavin plus blue diode laser with different power densities (0.4-1.0 W/cm2) as well as chlorhexidine (CHX). The colony forming units (CFUs)/mL was calculated. Data were analyzed by one-way ANOVA. RESULTS: Antibacterial analysis indicated that the blue diode laser irradiation with curcumin and riboflavin provided a satisfactory reduction of the S. mutans level. In addition, S. mutans was more affected by curcumin + blue diode laser when the power density was set to 1.0 W/cm2 (P < 0.0001). Meanwhile, bacterial suspensions treated with CHX showed maximum colony number reduction, compared with the control (P < 0.0001). CONCLUSION: This study showed the blue diode laser along with curcumin had strong bactericidal effect on S. mutans, and this effect improved by increasing the power density.
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Antiinfecciosos , Curcumina , Fotoquimioterapia , Fotoquimioterapia/métodos , Streptococcus mutans/efectos de la radiación , Fármacos Fotosensibilizantes/farmacología , Curcumina/farmacología , Clorhexidina/farmacología , Antibacterianos , Riboflavina , BiopelículasRESUMEN
The direct application of light for photo-disinfection potentially provides a safe and novel modality to inhibit or eliminate cariogenic bacteria residing upon and within dentine. This study aimed to both; characterize the pattern of transmission of 405 nm light through molar dentine at different tooth locations, as well as, determine the irradiation parameters that are antibacterial for Streptococcus mutans under various growth conditions, including lawns, planktonic cultures, and biofilms. To determine the amount of light (405 nm) transmitted at different anatomical tooth locations; irradiance values were recorded after blue light (470-4054 mW/cm2) had traversed through occlusal, oblique, and buccal dentine sections; and three thicknesses - 1, 2 and 3 mm were investigated. To determine tubular density; scanning electron micrographs from 2 mm outer (dentine-enamel junction) and inner (pulp) dentine sections were analysed. For photo-disinfection studies; S. mutans was irradiated using the same 405 nm wavelength light at a range of doses (110-1254 J/cm2) in both biofilm and planktonic cultures. The inhibitory effect of the irradiation on bacterial lawns was compared by measuring zones of inhibition; and for planktonic cultures both spectrophotometric and colony forming unit (CFU) assays were performed. A live/dead staining assay was utilised to determine the effect of irradiation on bacterial viability in mature biofilms. Data indicated that increasing dentine thickness decreased light transmission significantly irrespective of its orientation. Occlusal and oblique samples exhibited higher transmission compared with buccal dentine. Oblique dentine 405 nm light transmission was comparable with that of occlusal dentine independent of section thickness. An increased tubule density directly positively correlated with light transmission. Irradiation at 405 nm inhibited S. mutans growth in both biofilm and planktonic cultures and a dose response relationship was observed. Irradiation at doses of 340 and 831 J/cm2 led to significant reductions in bacterial growth and viability; as determined by CFU counting and live/dead staining. Data suggests that phototherapy approaches utilising a 405 nm wavelength have therapeutic potential to limit cariogenic bacterial infections both at the surface and within dentine.
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Dentina/efectos de la radiación , Desinfección/métodos , Luz , Adulto , Color , Dentina/microbiología , Femenino , Humanos , Masculino , Viabilidad Microbiana/efectos de la radiación , Streptococcus mutans/fisiología , Streptococcus mutans/efectos de la radiación , Adulto JovenRESUMEN
OBJECTIVE: We evaluated the effect of antimicrobial photodynamic therapy (a-PDT) with Rose Bengal and blue light LED on bacteria that initiate and promote dental caries. DESIGN: Colony forming units of Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis, and Lactobacillus salivarius under planktonic and biofilm conditions were counted after a-PDT treatment using Rose Bengal and blue light LED. In addition, cariogenic bacteria from saliva and dental plaques from ten volunteers were used for evaluation of a-PDT treatment. RESULTS: We found that a-PDT using Rose Bengal at > 10 µg/mL had antimicrobial effects on oral Gram-positive S. mutans, S. sobrinus, S. sanguinis, and L. salivarius under both planktonic and biofilm conditions. The effect was also observed for cariogenic bacteria that formed biofilms containing water-insoluble glucans, through which the bacteria are firmly attached to the tooth surface. Moreover, a-PDT led to a marked reduction in cariogenic bacteria in saliva and dental plaques. CONCLUSION: a-PDT could be a useful approach for controlling dental caries in dental surgery.
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Antiinfecciosos , Fotoquimioterapia , Rosa Bengala/farmacología , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/efectos de la radiación , Antiinfecciosos/farmacología , Biopelículas/efectos de los fármacos , Biopelículas/efectos de la radiación , Caries Dental/tratamiento farmacológico , HumanosRESUMEN
Caries-related biofilms and associated complications are significant threats in dentistry, especially when biofilms grow over dental restorations. The inhibition of cariogenic biofilm associated with the onset of carious lesions is crucial for preventing disease recurrence after treatment. This in vitro study defined optimized parameters for using a photosensitizer, toluidine blue O (TBO), activated via a red light-emitting diode (LED)-based wireless device to control the growth of cariogenic biofilms. The effect of TBO concentrations (50, 100, 150, and 200 µg/mL) exposed to light or incubated in the dark was investigated in successive cytotoxicity assays. Then, a mature Streptococcus mutans biofilm model under sucrose challenge was treated with different TBO concentrations (50, 100, and 150 µg/mL), different light energy doses (36, 108, and 180 J/cm2), and different incubation times before irradiation (1, 3, and 5 min). The untreated biofilm, irradiation with no TBO, and TBO incubation with no activation represented the controls. After treatments, biofilms were analyzed via S. mutans colony-forming units (CFUs) and live/dead assay. The percentage of cell viability was within the normal range compared to the control when 50 and 100 µg/mL of TBO were used. Increasing the TBO concentration and energy dose was associated with biofilm inhibition (p < 0.001), while increasing incubation time did not contribute to bacterial elimination (p > 0.05). Irradiating the S. mutans biofilm via 100 µg/mL of TBO and ≈180 J/cm2 energy dose resulted in ≈3-log reduction and a higher amount of dead/compromised S. mutans colonies in live/dead assay compared to the control (p < 0.001). The light energy dose and TBO concentration optimized the bacterial elimination of S. mutans biofilms. These results provide a perspective on the determining parameters for highly effective photo-killing of caries-related biofilms and display the limitations imposed by the toxicity of the antibacterial photodynamic therapy's chemical components. Future studies should support investigations on new approaches to improve or overcome the constraints of opportunities offered by photodynamic inactivation of caries-related biofilms.
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Biopelículas/efectos de la radiación , Luces de Curación Dental , Caries Dental/terapia , Streptococcus mutans/efectos de la radiación , Animales , Recuento de Colonia Microbiana , Caries Dental/microbiología , Relación Dosis-Respuesta en la Radiación , Ratones , Fármacos Fotosensibilizantes/efectos adversos , Células RAW 264.7 , Streptococcus mutans/patogenicidad , Streptococcus mutans/fisiología , Cloruro de Tolonio/efectos adversosRESUMEN
Antibacterial photodynamic therapy (aPDT) and antibacterial blue light (aBL) are emerging treatment methods auxiliary to mechanical debridement for periodontitis. APDT provided with near-infrared (NIR) light in conjunction with an indocyanine green (ICG) photosensitizer has shown efficacy in several dental in-office-treatment protocols. In this study, we tested Streptococcus mutans biofilm sensitivity to either aPDT, aBL or their combination dual-light aPDT (simultaneous aPDT and aBL) exposure. Biofilm was cultured by pipetting diluted Streptococcus mutans suspension with growth medium on the bottom of well plates. Either aPDT (810 nm) or aBL (405 nm) or a dual-light aPDT (simultaneous 810 nm aPDT and 405 nm aBL) was applied with an ICG photosensitizer in cases of aPDT or dual-light, while keeping the total given radiant exposure constant at 100 J/cm2. Single-dose light exposures were given after one-day or four-day biofilm incubations. Also, a model of daily treatment was provided by repeating the same light dose daily on four-day and fourteen-day biofilm incubations. Finally, the antibacterial action of the dual-light aPDT with different energy ratios of 810 nm and 405 nm of light were examined on the single-day and four-day biofilm protocols. At the end of each experiment the bacterial viability was assessed by colony-forming unit method. Separate samples were prepared for confocal 3D biofilm imaging. On a one-day biofilm, the dual-light aPDT was significantly more efficient than aBL or aPDT, although all modalities were bactericidal. On a four-day biofilm, a single exposure of aPDT or dual-light aPDT was more efficient than aBL, resulting in a four logarithmic scale reduction in bacterial counts. Surprisingly, when the same amount of aPDT was repeated daily on a four-day or a fourteen-day biofilm, bacterial viability improved significantly. A similar improvement in bacterial viability was observed after repetitive aBL application. This viability improvement was eliminated when dual-light aPDT was applied. By changing the 405 nm to 810 nm radiant exposure ratio in dual-light aPDT, the increase in aBL improved the antibacterial action when the biofilm was older. In conclusion, when aPDT is administered repeatedly to S. mutans biofilm, a single wavelength-based aBL or aPDT leads to a significant biofilm adaptation and increased S. mutans viability. The combined use of aBL light in synchrony with aPDT arrests the adaptation and provides significantly improved and sustained antibacterial efficacy.
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Adaptación Biológica/efectos de los fármacos , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Verde de Indocianina/farmacología , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Streptococcus mutans/efectos de los fármacos , Adaptación Biológica/efectos de la radiación , Carga Bacteriana/efectos de los fármacos , Carga Bacteriana/efectos de la radiación , Biopelículas/efectos de la radiación , Humanos , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Higiene Bucal/métodos , Periodontitis/tratamiento farmacológico , Streptococcus mutans/efectos de la radiaciónRESUMEN
This study investigated the bactericidal effect, the underlying mechanisms of treatment, and recovery of biocompatibility of the infected titanium surface using a combination treatment of silver ion application and ultraviolet-A (UV-A) light irradiation. Streptococcus mutans and Aggregatibacter actinomycetemcomitans were used in suspension and as a biofilm on a titanium surface to test for the bactericidal effect. The bactericidal effect of the combination treatment was significantly higher than that of silver ion application or UV-A light irradiation alone. The bactericidal effect of the combination treatment was attributable to hydroxyl radicals, which generated from the bacterial cell wall and whose yield increased with the silver concentration. To assess the biocompatibility, proliferation and calcification of MC3T3E1 cells were evaluated on the treated titanium surface. The treated titanium screws were implanted into rat tibias and the removal torques were measured 28 days post-surgery. The titanium surface that underwent the combination treatment exhibited recovery of biocompatibility by allowing cellular proliferation or calcification at levels observed in the non-infected titanium surfaces. The removal torque 28 days after surgery was also comparable to the control values. This approach is a novel treatment option for peri-implantitis.
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Aggregatibacter actinomycetemcomitans/crecimiento & desarrollo , Antibacterianos/administración & dosificación , Biopelículas/crecimiento & desarrollo , Radical Hidroxilo/química , Infecciones por Pasteurellaceae/prevención & control , Plata/administración & dosificación , Streptococcus mutans/crecimiento & desarrollo , Titanio/química , Aggregatibacter actinomycetemcomitans/efectos de los fármacos , Aggregatibacter actinomycetemcomitans/efectos de la radiación , Animales , Antibacterianos/química , Biopelículas/efectos de los fármacos , Biopelículas/efectos de la radiación , Ratones , Infecciones por Pasteurellaceae/microbiología , Periimplantitis/microbiología , Periimplantitis/terapia , Ratas , Ratas Wistar , Plata/química , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/efectos de la radiación , Tibia/microbiología , Tibia/cirugía , Rayos UltravioletaRESUMEN
Dental caries is a complex multifactorial chronic infectious disease guided by several risk or protective factors. Saliva has an important role in caries and the remineralization process. Caries risk assessment is defined as the probability of new caries lesion development or the existing lesion progression in a given time period. Caries diagnostics and risk factor assessment are followed by targeted elimination of risk factors and less conservative but abundant preventive therapeutic measures. The aim of our prospective randomized study was to elucidate on how photobiomodulation of major salivary glands with polychromatic light or LED light affects caries risk factors in high caries-risk patients. Thirty-six patients were assigned to one of the following three experimental groups: the first, irradiated with polarized polychromatic light (40 mW/cm2, wavelengths 480-3400 nm); the second, a continuous LED light (16 mW/cm2, wavelengths 625, 660, 850 nm); the third, same LED light in a pulsed mode. The fourth group was the control, for which a non-therapeutic visible light was used. Light was administered extra-orally bilaterally above the parotid and submandibular glands for 10 min and intra-orally above the sublingual glands for 5 min, 3 times a week, for 4 consecutive weeks. Each patient's caries risk was assessed according to Cariogram before and after therapy. Caries risk factors were determined from samples of saliva before therapy, two weeks after it commenced, at the end of therapy, and four weeks after the end of therapy. At the end of treatment, the following findings were obtained: In the group irradiated with polarized polychromatic light and in the group irradiated with continuous LED light, the Streptococcus mutans and Lactobacillus counts decreased and salivary buffering capacity increased (p < 0.05). In the group irradiated with pulsed LED light, Streptococcus mutans counts decreased and unstimulated salivary flow and salivary buffering capacity increased (p < 0.05). In all three experimental groups, caries risk was lower (p < 0.05). In the placebo control group, there were no statistically significant differences between parameters before and after therapy. We concluded that photobiomodulation of major salivary glands in high caries-risk patients can reduce the cariogenic bacteria in saliva and improve some salivary parameters, thus reducing caries risk.
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Caries Dental/microbiología , Caries Dental/prevención & control , Terapia por Luz de Baja Intensidad , Glándulas Salivales/microbiología , Glándulas Salivales/efectos de la radiación , Carga Bacteriana/efectos de la radiación , Femenino , Humanos , Lactobacillus/fisiología , Lactobacillus/efectos de la radiación , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Medición de Riesgo , Streptococcus mutans/fisiología , Streptococcus mutans/efectos de la radiaciónRESUMEN
The potential anti-cariogenic effect of blue light was evaluated using an oral biofilm model. Two species, Streptococcus mutans and Streptococcus sanguinis, were cultivated ex vivo on bovine enamel blocks for 24 h, either separately or mixed together, then exposed to blue light (wavelengths 400-500 nm) using 112 J/cm2. Twenty four or 48 h after exposure to light the biofilm structure and biomass were characterized and quantified using SEM and qPCR, respectively. Bacterial viability was analyzed by CLSM using live/dead bacterial staining. Gene expression was examined by RT-qPCR. After exposure to light, S. mutans biomass in mono-species biofilm was increased mainly by dead bacteria, relative to control. However, the bacterial biomass of S. mutans when grown in mixed biofilm and of S. sanguinis in mono-species biofilm was reduced after light exposure, with no significant change in viability when compared to control. Furthermore, when grown separately, an upregulation of gene expression related to biofilm formation of S. mutans, and downregulation of similar genes of S. sanguinis, were measured 24 h after exposure to blue light. However, in mixed biofilm, a downregulation of those genes in both species was observed, although not significant in S. mutans. In conclusion, blue light seems to effectively alter the bacterial biomass by reducing the viability and virulence characteristics in both bacterial species and may promote the anti-cariogenic balance between them, when grown in a mixed biofilm. Therefore, exposure of oral biofilm to blue light has the potential to serve as a complementary approach in preventive dentistry.
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Biopelículas/efectos de la radiación , Luz , Modelos Biológicos , Boca/microbiología , Streptococcus mutans/efectos de la radiación , Streptococcus sanguis/efectos de la radiación , Animales , Biopelículas/crecimiento & desarrollo , Bovinos , Esmalte Dental/microbiología , Esmalte Dental/ultraestructura , Regulación Bacteriana de la Expresión Génica/efectos de la radiación , Streptococcus mutans/genética , Streptococcus mutans/ultraestructura , Streptococcus sanguis/genética , Streptococcus sanguis/ultraestructuraRESUMEN
Objective: This study aimed to investigate if ß-cyclodextrin nanoparticles potentiate the photodynamic antimicrobial chemotherapy (PACT) effects in single and microcosm oral biofilms using methylene blue (MB) and a red laser. Background data: Studies of PACT have demonstrated promising effects; however, the association of nanoparticles with photosensitizers could enhance the antimicrobial result. Materials and methods: Biofilms were grown on enamel blocks either with Streptococcus mutans or in a microcosm model (salivary microorganisms) supplemented with sucrose. PACT using 50 µM MB associated or not with 32 µM encapsulated ß-cyclodextrin with MB for 5 min, followed by irradiation with red laser (λ = 660 nm, 320 J/cm2), was conducted and the counts of viable microorganisms in proper selective media were determined. Data were analyzed by one-factor ANOVA, followed by Tukey's test, or Kruskal-Wallis test, followed by Dunn's post hoc test, all with a significance level of 5%. Results: In the single-species biofilm model, a significant reduction in S. mutans counts was found for all groups when light was present. In the microcosm biofilm model, no significant difference was found among the groups for total streptococci, but a significant reduction of S. mutans was observed for the PACT group of encapsulated ß-cyclodextrin+MB. However, no statistically significant difference was observed among the PACT groups. Conclusions: PACT with ß-cyclodextrin mediated with MB associated with a red laser reduced S. mutans in microcosm biofilms. However, the presence of ß-cyclodextrin nanoparticles did not potentiate the PACT effects in single or microcosm oral biofilms.
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Biopelículas/efectos de los fármacos , Nanopartículas , Fotoquimioterapia/métodos , Fármacos Fotosensibilizantes/farmacología , Streptococcus mutans/efectos de los fármacos , beta-Ciclodextrinas/farmacología , Biopelículas/efectos de la radiación , Azul de Metileno , Viabilidad Microbiana , Streptococcus mutans/efectos de la radiaciónRESUMEN
Laser irradiation has been proposed as a preventive method against dental caries since it is capable to inhibit enamel demineralization by reducing carbonate and modifying organic matter, yet it can produce significant morphological changes. The purpose of this study was to evaluate the influence of Er:YAG laser irradiation on superficial roughness of deciduous dental enamel and bacterial adhesion. Fifty-four samples of deciduous enamel were divided into three groups (n = 18 each). G1_control (nonirradiated); G2_100 (7.5 J/cm2 ) and G3_100 (12.7 J/cm2 ) were irradiated with Er:YAG laser at 7.5 and 12.7 J/cm2 , respectively, under water irrigation. Surface roughness was measured before and after irradiation using a profilometer. Afterwards, six samples per group were used to measure bacterial growth by XTT cell viability assay. Adhered bacteria were observed using confocal laser scanning microscopy (CLSM) and a scanning electron microscopy (SEM). Paired t-, one-way analysis of variance (ANOVA), Kruskal-Wallis and pairwise Mann-Whitney U tests were performed to analyze statistical differences (p < .05). Before treatment, samples showed homogenous surface roughness, and after Er:YAG laser irradiation, the surfaces showed a significant increase in roughness values (p < .05). G3_100 (12.7 J/cm2 ) showed the highest amount of Streptococcus mutans adhered (p < .05). The increase in the roughness of the tooth enamel surfaces was proportional to the energy density used; the increase in surface roughness caused by laser irradiation did not augment the adhesion of Streptococcus sanguinis; only the use of the energy density of 12.7 J/cm2 favored significantly the adhesion of S. mutans.
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Adhesión Bacteriana/efectos de la radiación , Caries Dental/prevención & control , Esmalte Dental/efectos de la radiación , Láseres de Estado Sólido/uso terapéutico , Streptococcus mutans/fisiología , Streptococcus/fisiología , Adhesión Bacteriana/fisiología , Humanos , Microscopía Electrónica de Rastreo , Streptococcus/crecimiento & desarrollo , Streptococcus/efectos de la radiación , Streptococcus mutans/crecimiento & desarrollo , Streptococcus mutans/efectos de la radiación , Streptococcus sanguis , Propiedades de Superficie/efectos de la radiaciónRESUMEN
Objective: This study was performed to determine the bactericidal effects of erbium:yttrium-aluminum-garnet (Er:YAG) laser irradiation and the morphological and chemical composition changes in bovine dentin. Methods: Dentin slabs were prepared from bovine incisors, and then cultured with Streptococcus mutans to produce bacteria-infected dentin samples. The samples were randomly divided into five groups with Er:YAG laser irradiation energy densities of 0, 6.37, 12.73, 19.11, and 25.47 J/cm2. After irradiation, samples were stained and observed by confocal laser scanning microscopy. The bactericidal abilities were measured using live/dead staining. The morphology and chemical components were investigated by scanning electron microscopy and energy-dispersive spectrometry. Results: After irradiation, the elimination of bacteria and the smear layer were significantly better in the high energy density groups (19.11, 25.47 J/cm2) than in the low energy density groups (6.37, 12.73 J/cm2; p < 0.001). On morphological examination, the group with minimum energy density (6.37 J/cm2) showed superficial melting. In the high energy density groups (12.73, 19.11, and 25.47 J/cm2), laser-irradiated dentin showed a clean surface with open orifices. Significant increases were observed in the weight percentages of calcium (from 19.75 ± 0.69 to 34.47 ± 2.91, p < 0.001) and phosphate (from 8.58 ± 0.43 to 15.10 ± 1.81, p < 0.001), whereas significant decreases were observed for oxygen (from 49.84 ± 0.69 to 36.39 ± 2.86, p < 0.001) and carbon (from 26.06 ± 3.58 to 12.80 ± 2.26, p < 0.01) with increasing energy density. Conclusions: This study confirmed that Er:YAG laser irradiation has bactericidal and dentin conditioning effects.
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Dentina/microbiología , Dentina/efectos de la radiación , Láseres de Estado Sólido/uso terapéutico , Terapia por Luz de Baja Intensidad , Streptococcus mutans/efectos de la radiación , Animales , Bovinos , Dentina/diagnóstico por imagen , Microscopía Confocal , Técnicas de Cultivo de TejidosRESUMEN
Objective: The aim of this study was to evaluate the effect of photodynamic therapy (PDT) on multispecies oral caries biofilms composed of Streptococcus mutans, Lactobacillus casei, and Candida albicans. Background: The abovementioned microorganisms largely cause dental caries, especially early childhood caries (ECC), by synthesizing of acids in the presence of sugar. PDT is considered an effective process to remove oral biofilms, and erythrosine, an oral bacterial disclosing agent, is an ideal dye that can be used as a photosensitizer in PDT. However, until now, there are no studies that have reported the effect of erythrosine-mediated PDT on biofilms, including the three microorganisms. Methods: The biofilms were formed on hydroxyapatite discs, and erythrosine was used as the photosensitizer, diluted to a concentration of 40 µM for 3 min. Light was irradiated for 10 and 20 sec using a blue light-emitting diode dental curing light. After the experiment, the colony-forming units of each microbial group cultured on blood agar plates were counted, and a confocal laser-scanning microscope was used to evaluate the effect of PDT. Results: The counts of all three microorganisms significantly decreased in the PDT group compared with those in the control group. For S. mutans and L. casei, there was a larger decrease proportional to the amount of energy irradiated. Conclusions: Overall, PDT showed a significant antimicrobial effect against oral biofilms composed of the three microorganisms, suggesting its potential clinical application for infants with ECC.
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Biopelículas/efectos de la radiación , Candida albicans/efectos de la radiación , Caries Dental/microbiología , Lacticaseibacillus casei/efectos de la radiación , Fotoquimioterapia , Streptococcus mutans/efectos de la radiación , Luces de Curación Dental , Eritrosina , Fármacos Fotosensibilizantes , Células MadreRESUMEN
INTRODUCTION: This study evaluated the efficacy of photodynamic inactivation (PDI) with hematoporphyrin IX (H) and modified hematoporphyrin IX (MH) at 10 µmol/L, using a blue light-emitting diode (LED), fluence of 75 J/cm,2 over planktonic cultures and biofilm of Streptococcus mutans (UA 159). METHODS: Suspensions containing 107 cells/mL were tested under different experimental conditions: a) H and LED (H+L+), b) MH and LED (MH+L+), c) only LED (P-L+), d) only H (H+L-), e) only MH (MH+L-), and f) control group, no LED or photosensitizer treatment (P-L-). The study also evaluated the effect of PDI on S mutans biofilm on metallic or ceramic brackets bonded on specimens of human teeth. The strains were seeded onto Mitis salivarius-bacitracin-sacarose agar to determine the number of colony-forming units. RESULTS: H and MH under LED irradiation were effective on planktonic cultures (P <0.0001). H and MH (H+L+ and MH+L+) caused a reduction of 3.80 and 6.78 log10 CFU/mL. PDI with the use of H or MH and LED exerted a strong antimicrobial effect over S mutans showing 54% and 100% reduction, respectively. PDI on S mutans biofilm on metallic and ceramic brackets with the use of H was not effective (P = 0.0162, P = 0.1669), however, MH caused a significant reduction of 44% and 53% of the cell count on metallic and ceramic brackets, respectively (P = 0.0020, P = 0.004). CONCLUSIONS: In vitro planktonic cultures with the use of H or MH and LED exerted significant antimicrobial activity. No effect was observed on S mutans biofilm on either bracket type with the use of H, MH showed better results, suggesting a promising use against dental caries and white spot lesions.
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Biopelículas/efectos de los fármacos , Biopelículas/efectos de la radiación , Caries Dental/etiología , Caries Dental/prevención & control , Hematoporfirinas/farmacología , Ortodoncia Correctiva/efectos adversos , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Plancton/efectos de los fármacos , Plancton/efectos de la radiación , Streptococcus mutans/efectos de los fármacos , Streptococcus mutans/efectos de la radiación , Humanos , Técnicas In Vitro , Streptococcus mutans/fisiologíaRESUMEN
The study aims to assess the utility of dental acid etchant containing 37% phosphoric acid and methylene blue dye (DAE) as a sensitizing agent for photodynamic therapy (PDT) to reduce Streptococci mutans in dentinal caries. Forty-five permanent third molars were sectioned and the coronal dentin exposed. A cariogenic challenge was performed using brain-heart infusion (BHI) supplemented with 0.5% yeast extract, 1% glucose, 1% sucrose, and S. mutans ATCC 25175 standardized to 0.5 McFarland turbidity. Specimens were incubated in anaerobic jars at 37 °C for 15 days. During this period, BHI broth was renewed every 24 h. After 15 days, specimens were randomly divided into three groups (n = 15): DAE, application of dental acid etchant containing 37% phosphoric acid and methylene blue dye for 15 s; LLL, application of low-level laser (wavelength 660 nm, energy 4 J/cm2, power 5 W) for 15 s; and PDT, application of DAE for 15 s followed by LLL irradiation (660 nm, 4 J/cm2, 5 W). Carious tissue from each specimen was collected before and after the applications. Five decimal dilutions were performed and the resulting solution was seeded in mitis-salivarius-bacitracin agar. Plates were incubated in anaerobic jars at 37 °C for 48 h. Analysis of variance (ANOVA) with post hoc Tukey's test was used to compare total S. mutans counts. Significant reductions in S. mutans were observed after DAE application (40.70%, p < 0.0001), LLL (12.35%, p = 0.0036), and PDT (55.22%, p < 0.0001). Dental acid etchant containing 37% phosphoric acid and methylene blue dye can be used as a photosensitizing agent for PDT to reduce S. mutans burden in dentinal caries.
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Grabado Ácido Dental , Caries Dental/tratamiento farmacológico , Caries Dental/microbiología , Fotoquimioterapia , Fármacos Fotosensibilizantes/uso terapéutico , Streptococcus mutans/efectos de los fármacos , Recuento de Colonia Microbiana , Humanos , Luz , Streptococcus mutans/crecimiento & desarrollo , Streptococcus mutans/efectos de la radiaciónRESUMEN
The purpose of this study was to evaluate the effects of Nd:YAG laser with flat-top handpiece on the in vitro growth of Candida albicans and Streptococcus mutans. The incidence of C. albicans (opportunistic commensal) and S. mutans (facultatively anaerobic) infections is increasing, despite available treatments. Cultures of Streptococcus mutans and Candida albicans were irradiated using Nd:YAG laser (LightWalker, Fotona) with flat-top handpiece (Genova, LightWalker, Fotona) at the following parameters: group G1: 0.25 W, 10 Hz, 15 s, 3 J and group G2: 1 W, 10 Hz, 60s, 59 J. The results were evaluated directly and 24 h after irradiation using a quantitative culture method (estimation of colony-forming units in 1 ml of suspension, cfu/ml), and microscopic analysis with Janus green stain and compared with control group in which laser was not applied. C. albicans was reduced by 20 up to 54% for G1, and for G2 by 10 up to 60% directly after the application. The cfu/ml values for S. mutans decreased by 13% (p = 0.1771) for G1 and 89% (p < 0.0001) for G2. In both test groups 24 h after the application, the number of colony-forming units decreased by 15-46% for G1 and by 15-64% for G2. The arrested cell division, increasing the surface area and increasing the number of metabolically inactive cells, were observed in morphometric analysis. Macroscopic and microscopic analyses revealed a reduction in cell number and a significant decrease of cell metabolism after laser application for both C. albicans and S. mutans.