Comparative Effect of Two Red Lights on Streptococcus mutans Biofilms and Assessment of Temperature Variances in Human Teeth During In Vitro Photodynamic Antimicrobial Chemotherapy.

Objective: The goals of this investigation were to compare the effect of photodynamic antimicrobial chemotherapy (PACT) with two different red lights on in vitro Streptococcus mutans biofilms, as well as to assess the temperature variances caused by PACT on human teeth. Methods: S. mutans biofilms (n = 3) were grown on hydroxyapatite disks, and the antimicrobial effect of PACT was evaluated using toluidine blue O (100 µg/mL) associated with Laserbeam® (LB 56.6 J/cm2) and LumaCare™ (LC -56.6, 158.5, 317.0, and 475.6 J/cm2). Pulpal temperature variances were analyzed using a digital thermocouple placed into the pulp chamber and positioned at the cement-enamel junction level of five teeth samples during irradiation times of 300, 600, and 900 sec for LB, and 22, 60, 120, and 180 sec for LC. The mean average temperature variance was calculated for each group. All data were analyzed through analysis of variance. Results: LB (900 sec) and LC (22 sec) induced similar reductions in the viability of microorganisms. LB did not cause statistically significant increase of temperature, regardless of experimental time, and LC caused temperature increase within the safe spectrum up to 60 sec. Conclusions: PACT seems to be a minimal invasive approach for reducing the viability of cariogenic bacteria. Thus, when applied in vitro for times equal or inferior to 900 and 60 sec for LB and LC, respectively, these light sources might be considered harmless to tooth structures.

Twice-daily red and blue light treatment for Candida albicans biofilm matrix development control.

Phototherapy has been proposed as a direct means of affecting local bacterial infections. However, the use of phototherapy to prevent fungal biofilm development has received comparatively less attention. This study aimed to determine the effects of red light treatment and blue light treatment, without a photosensitizer, on the development of Candida albicans biofilm. During the development of 48-h biofilms of C. albicans SN 425 (n = 10), the biofilms were exposed twice-daily to noncoherent blue and red light (LumaCare; 420 nm and 635 nm). The energy density applied was 72 J cm-2 for blue light and 43.8 J cm2, 87.6 J cm2, and 175.5 J cm2 for red light. Positive control (PC) and negative control (NC) groups were treated twice-daily for 1 min with 0.12% chlorhexidine (CHX) and 0.89% NaCl respectively. Biofilms were analyzed for colony forming units (CFU), dry-weight, and exopolysaccharides (EPS-soluble and EPS-insoluble). Data was analyzed by one-way ANOVA and Tukey post hoc test (α = 0.05). Dry-weight was lower than NC (p < 0.001) and approached PC levels with both red and blue light treatments. CFU were also lower in groups exposed to blue light and higher durations of red light (p < 0.05). EPS-soluble and EPS-insoluble measures were variably reduced by these light exposures. In conclusion, twice-daily exposure to both blue and red lights affect the biofilm development and physiology of polysaccharide production and are potential mechanisms for the control of C. albicans biofilm matrix development.

Effect of Photodynamic Antimicrobial Chemotherapy on Mono- and Multi-Species Cariogenic Biofilms: A Literature Review.

OBJECTIVE: The aim of this literature review is to study the effect of photodynamic antimicrobial chemotherapy (PACT) on mono- and multi-species cariogenic biofilms. METHODS: To this purpose, the database, PubMed, was searched using the descriptors, photodynamic therapy, antimicrobial photodynamic chemotherapy, and photoinactivation, associated with the mandatory presence of the word biofilm. A total of 98 references published from 2003 to 2016 were selected. Moreover, literature reviews (15), investigations that did not have biofilms related to dental caries (65), and those that did not have Streptococcus mutans count as an outcome (7) were excluded, yielding a final amount of 11 publications. RESULTS: The results revealed that Toluidine Blue O was the most used photosensitizer. Among the sources of light, light-emitting diode was the choice, and the biofilm models varied between in vitro and in situ. Multi-species biofilms were more resistant to the antimicrobial effects of PACT due to the thickness and complexity they have, which impede the penetration of the photosensitizer. This fact may also be associated with the type of photosensitizer used as well as with the light exposure time since the antimicrobial effect seems to be dose dependent. Despite this, in all the included publications, the therapy was effective in reducing S. mutans count. CONCLUSIONS: This review demonstrated that under different conditions, PACT is effective in reducing S. mutans count in monospecies biofilms. Multi-species biofilms were more resistant to the antimicrobial action of the therapy, possibly due to their thickness and complexity.

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm.

OBJECTIVE:: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. MATERIAL AND METHODS:: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. RESULTS:: 34 subjects (65.4%) harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%), Escherichia coli (23.5%), and Enterobacter aerogenes (23.5%) were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 µg/ mL) and cefotaxime (MIC90≥2 µg/mL). CONCLUSION:: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice.

Occurrence and antimicrobial susceptibility of enteric rods and pseudomonads isolated from the dental prostheses biofilm

ABSTRACT Aspiration of oral bacteria leads to cardiac and respiratory infectious diseases and dentures can act as a reservoir for pathogenic microorganisms. Objective: To determine the occurrence and the in vitro antimicrobial susceptibility of enteric rods and pseudomonads from the denture biofilm of 52 subjects at the Center for Dental Specialties of Sobral/ Ceara, Brazil. Material and Methods: Denture biofilm was collected and samples plated on MacConkey agar. The isolated bacterial colonies were identified using the BBL Crystal enteric/non-fermenter system. Antibiotic bacterial susceptibility was assessed by the disc diffusion method of amoxicillin, amoxicillin/clavulanic acid, doxycycline, tetracycline, tobramycin, imipenem, cefotaxime, and ciprofloxacin. The Minimum Inhibitory Concentration (MIC) of cefotaxime, tobramycin, doxycycline, imipenem, and ciprofloxacin was determined for 40 species by E-test. Results: 34 subjects (65.4%) harbored enteric rods in their prostheses. Klebsiella pneumoniae (26.5%), Escherichia coli (23.5%), and Enterobacter aerogenes (23.5%) were the most prevalent species. All organisms were susceptible to ciprofloxacin and most species were resistant to amoxicillin or amoxicillin/clavulanic acid, demonstrating variable sensitivity patterns to other antimicrobials. However, the MIC showed the emergence of strains with reduced sensitivity to ciprofloxacin (MIC90≥3 μg/ mL) and cefotaxime (MIC90≥2 μg/mL). Conclusion: The findings show high prevalence of nosocomial diseases-related bacterial species and low susceptibility to antimicrobial drugs. Therefore, these results imply caution against the indiscriminate use of broad spectrum antibiotics in dental practice.

Serratia marcescens resistance profile and its susceptibility to photodynamic antimicrobial chemotherapy.

BACKGROUND: Some authors have reported the antimicrobial action of photodynamic antimicrobial chemotherapy (PACT) on bacteria related to nosocomial infections but there are few studies evaluating PACT on Serratia marcescens grown as planktonic cultures or as biofilms. The purpose of this study was to analyze the S. marcescens resistance profile and its susceptibility to PACT. METHODS: Initially, 55 S. marcescens strains isolated from environmental, oral and extra-oral infections were tested by antimicrobial resistance to cefotaxime (CTX), imipenem (IPM), ciprofloxacin (CIP), tobramycin (TOB) and doxycycline (DOX) using E-test(®). Following, isolates grown as planktonic cultures or biofilms were submitted to PACT using the association of a light-emitting diode and toluidine blue (TBO). The E-test(®) results demonstrated intermediated sensitive strains to CTX, IMP, TOB, and DOX; and resistant strains to CTX, TOB, DOX and CIP. Also, CTX and IMP demonstrated variation when CLSI 2007 and CLSI 2015 were compared. RESULTS: Planktonic cultures and biofilms submitted to PACT demonstrated counts varying from 10(11) to 10(7) for planktonic cultures and 10(10) to 10(7) for biofilms. There were no statistical differences in the results when planktonic cultures and biofilms were compared. CONCLUSIONS: Increase in the profile of S. marcescens resistance was observed when CLSI 2007 and CLSI 2015 were compared. Also, IMP remains as the drug with lower rate of resistance. Additionally, both S. marcescens planktonic cultures and early biofilms are susceptible to PACT under tested conditions.

In situ assessment of effects of the bromide- and fluoride-incorporating adhesive systems on biofilm and secondary caries.

AIM: This in situ study assessed the effects of adhesive systems containing or not fluoride and/or the antibacterial monomer 12-methacryloyloxydodecylpyridinium bromide (MDPB) on the microbiological composition of dental biofilm and enamel demineralization. MATERIALS AND METHODS: During two phases of 14 days, ten volunteers wore intraoral palatal appliances containing two slabs of human enamel according to a double-blind, crossover design. The slabs were randomly restored using a composite resin and one of the following adhesive systems: All-Bond SE(TM) (self-etch, fluoride/MDPB free adhesive, AB) and Clearfl Protect Bond (self-etch containing fluoride and MDPB adhesive, CB). The biofilm formed on the slabs was analyzed with regard to total and mutans streptococci and lactobacilli counts. Demineralization represented by integrated area of hardness × lesion depth Delta S ( ΔS) was determined on enamel by analysis of cross-sectional microhardness, at 20 and 70 µm from the restoration margin. Data were analyzed by ANOVA. RESULTS: No statistically significant difference was found either in enamel demineralization or in the microbiological composition of dental biofilm. CONCLUSION: All adhesive systems containing or not fluoride and/or MDPB tested were unable to inhibit secondary caries in the in situ model used in the present research.

Characterization of antimicrobial photodynamic therapy-treated Streptococci mutans: an atomic force microscopy study.

UNLABELLED: Abstract Objective: The aim of the present study was to examine the size and shape of Streptococcus mutans bacterial cells of infected dentin substrate subjected to photodynamic therapy (PDT) using atomic force microscopy (AFM). BACKGROUND DATA: New trends in the application of AFM have been developed in the field of dentistry, making AFM a useful technique in high resolution imaging of biological structures and processes. MATERIALS AND METHODS: PDT was completed using an efficient light-emitting diode source (LED - λ=620-660 nm) with total light dose of 94 J/cm(2) in the presence of the photosensitizer toluidine blue O (TBO). Dentin specimens were immersed in brain heart infusion (BHI) broth inoculated with S. mutans for 5 days to induce caries in vitro. After demineralization, the samples were subjected to a series of treatments in which carious dentin infected by S. mutans was exposed to 0.9% sodium chlorite (NaCl) solution (control) for 10 min, or subjected to PDT-TBO photosensitizer followed by light exposure (energy density of 94 J/cm(2)). RESULTS: Three-dimensional (3-D) images and cross-sectional measurements showed rod and diplococcic cell shapes. Photoinactivated bacterial cells did not differ from the control with respect to their cross-sectional shape, but they did show a reduction in size. CONCLUSIONS: Photodynamic therapy decreased the diameter of S. mutans cells and AFM may be used as a technique for bacterial cell analysis.

Use of 660-nm diode laser in the prevention and treatment of human oral mucositis induced by radiotherapy and chemotherapy.

OBJECTIVE: The aim of this multidisciplinary study was to evaluate quantitatively and qualitatively the effect of a 660-nm diode laser in the prevention and treatment of human oral mucositis (OM) in patients suffering from head and neck cancer who had undergone radiotherapy and chemotherapy. BACKGROUND DATA: OM is a severe oral lesion resulting from the toxic effects of treatment for cancer in the head and neck region. Low-level laser therapy is indicated to prevent and treat this oral complication and may be used alone or in association with conventional drug treatment, producing pain relief and wound repair. METHODS: This study included 72 patients with head and neck cancer treated at the Cancer Hospital of Mato-Grosso, Brazil, and divided into a control group (C; n = 36) and a laser group (L; n = 36). Laser therapy was performed in combination with radiotherapy and chemotherapy twice a week using a diode laser (lambda = 660 nm, power = 30 mW, spot size = 2 mm, energy = 2 J per point). RESULTS: Statistically significant differences were observed between the two groups. Patients in group L usually did not present with OM or pain, but all patients in group C presented with OM ranging from Level I to III associated with pain. This difference was significant from week 1 on, increased until week 4 and remained stable up to week 7. CONCLUSION: Laser therapy was effective in preventing and treating oral effects induced by radiotherapy and chemotherapy, thus improving the patient's quality of life.

Full-mouth ultrasonic debridement associated with amoxicillin and metronidazole in the treatment of severe chronic periodontitis.

BACKGROUND: The purpose of this study was to evaluate the adjunctive clinical, microbiologic, and immunologic effects of the systemic administration of amoxicillin and metronidazole in the full-mouth ultrasonic debridement of patients with severe chronic periodontitis. METHODS: Twenty-five patients presenting at least eight teeth with probing depth (PD) > or =5 mm and bleeding on probing (BOP) were selected and randomly assigned to full-mouth ultrasonic debridement + placebo (control group) or full-mouth ultrasonic debridement + amoxicillin and metronidazole (test group). The clinical outcomes evaluated were visible plaque index, BOP, position of the gingival margin, relative attachment level (RAL), and PD. Real-time polymerase chain reaction (PCR) was used for quantitative analysis of Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans), Porphyromonas gingivalis, and Tannerella forsythia (previously T. forsythensis). The enzyme-linked immunosorbent assay (ELISA) technique permitted the detection of prostaglandin E(2,) interleukin-1beta, and interferon-gamma levels in gingival crevicular fluid. All parameters were evaluated at baseline and at 3 and 6 months post-treatment. RESULTS: At 6 months, the test treatment resulted in lower BOP and an additional reduction (0.83 mm) in PD (P <0.05). Data also showed RAL gain > or =2 mm at 43.52% of sites in control patients compared to 58.03% of sites in test patients (P <0.05). However, both groups had similar mean RAL gain (1.68 and 1.88 mm for the control and test groups, respectively). Real-time PCR and ELISA failed to identify significant differences between the groups. CONCLUSIONS: Both treatments resulted in significant clinical improvements; however, there was a slight, but significantly greater, improvement in BOP and the percentage of sites with PD > or =5 mm exhibiting RAL gain > or =2 mm in the test group. Nevertheless, no improvement in the microbiologic or immunologic outcome was observed with the adjunctive use of systemic amoxicillin and metronidazole.

Fotobiologia: detecção da lesão de cárie dental com o uso da fluorescência a laser / Photobiology: caries detection by laser fluorescence

O uso da luz para o tratamento e prevenção de doenças na área médica e odontológica tem sido muito utilizado atualmente e pode ser chamado de fotobiologia. O DIAGNOdent (KaVo Biberach, Alemanha) consegue detectar, através da fluorescência do laser de diodo 655 nm, lesões iniciais que vão desde mínimas perdas minerais até lesões ocultas na dentina. Com a superfície do esmalte intacta consegue, também, determinar a atividade da cárie, ou seja, se no local da lesão há bactérias ativas ou inativas. A diminuição da prevalência da doença cárie em crianças e adolescentes tem exigido métodos de diagnóstico cada vez mais precisos, que nos forneçam dados complementares e que nos ajudem a compreender melhor todo o processo da doença cárie. O método de detecção por fluorescência a laser, DIAGNOdent, visa detectar precocemente as primeiras manifestações clínicas desta patologia, em uma fase que possamos evitar sua progressão através de métodos conservadores, numa abordagem atual de promoção da saúde.

Photobiology is the use of light in the treatment and prevention of diseases in the medical and dental areas. DIAGNOdent (KaVo Biberach, Alemanha), through fluorescence of diode laser 655 nm, is able to detect early lesions, from minimal mineral loss to lesions hidden in the dentine with intact enamel surface. It is also able to determine the caries activity, i.e., if there are active or inactive bacteria in the lesion site. Prevalence of caries disease in children and adolescentes has decreased and thus demands more precise diagnostic methods to furnish additional data to help understand the ,whole process. DIAGNOdent a laser fluorescence detection method, detects the clinical manifestations of this pathology at a very early stage. Thus, the progress of the disease is deterred, avoiding the use of conservative methods, which is in accordance with the current approach to buccal health promotion.

Terapia fotodinâmica no tratamento da doença periodontal / Photodynamic therapy on periodontal disease treatment

A redução de microorganismos patogênicos da superfície dental é um dos principais fatores envolvidos na prevenção e tratamento da doença periodontal. Nesse contexto a terapia fotodinâmica surge como um tratamento alternativo devido a sua habilidade em matar microorganismos. Nessa terapia, bactérias previamente sensibilizadas com um fotossensibilizador específico são irradiadas com uma luz de comprimento de onda complementar iniciando a formação de radicais orgânicos que podem culminar com a morte bacteriana. O objetivo dessa revisão de literatura é dar ao leitor informações sobre o uso da terapia fotodinâmica na redução de bactérias bucais e as novas perspectivas para o uso dessa terapia no tratamento da doença periodontal.

Elimination of pathogenic microorganisms from dental surface has been one of the most important factors related to periodontal disease control and prevention. In this context, photodynamic therapy became as an alternative treatment because of its ability to kill microorganisms. In this therapy, pre-sensitized bacteria irradiated with a suitable wavelength light beginning the production of free organic compounds that may kill bacteria. The aim of this review is to provide the reader with information about antimicrobial activity of photodynamic therapy and new perspectives for the use of this therapy in periodontal disease treatment.

Susceptibility of Streptococcus mutans biofilms to photodynamic therapy: an in vitro study.

OBJECTIVES: The purpose of this study was to evaluate the antimicrobial effect of toluidine blue O (TBO), in combination with either a helium/neon (HeNe) laser or a light-emitting diode (LED), on the viability and architecture of Streptococcus mutans biofilms. METHODS: Biofilms were grown on hydroxyapatite discs in a constant depth film fermentor fed with artificial saliva that was supplemented with 2% sucrose four times a day, thus producing a typical 'Stephan pH curve'. Photodynamic therapy was subsequently carried out on biofilms of various ages with light from either the HeNe laser or LED using energy densities of between 49 and 294 J/cm(2). RESULTS: Significant decreases in the viability of S. mutans biofilms were only observed when biofilms were exposed to both TBO and light, when reductions in viability of up to 99.99% were observed with both light sources. Overall, the results showed that the bactericidal effect was light dose-dependent and that older biofilms were less susceptible to photodynamic therapy. Confocal laser scanning microscopy images suggested that lethal photosensitization occurred predominantly in the outermost layers of the biofilms. CONCLUSIONS: Photodynamic therapy may be a useful approach in the treatment of dental plaque-related diseases.

Terapia fotodinâmica na odontologia (T. F. D.) / Photodynamic therapy in dentistry

A redução de microorganismos patogênicos da superfície dental e dos principais fatores envolvidos na prevenção e controle da doença cárie. Com esse propósito, a terapia fotodinâmica surge como um tratamento alternativo devido a sua habilidade em manter microorganismos. Nessa terapia, bactérias previamente sensibilizadas com um foto sensibilizador específico, são irradiadas com um laser de baixa potência iniciando a formação de radicais orgânicos que podem culminar com a morte bacteriana. O objetivo dessa revisão foi dar ao leitor informações sobre o uso da terapia fotodinâmica na redução de bactérias bucais, e as novas perspectivas para o uso dessa terapia na odontologia

Aplicaçäo da terapia fotodinâmica na descontaminaçäo bacteriana / Application of the photodinamic therapy in bacterial decontamination

A reduçäo de microrganismos patogênicos da superfície dental é um dos principais fatores envolvidos na preservaçäo e no controle da doença cárie. Neste estudo, avaliou-se, in vitro, o efeito antimicrobiano da terapia fotodinâmica sobre os microrganismos mais diretamente relacionados ao surgimento de cárie em humanos. Para tanto, utilizou-se um laser diodo de 660 nm, com densidade de energia de 28,8 J/cm², associado ao corante azul de toluidina O na concentraçäo de 100 µg/ml. Suspensöes bacterianas foram submetidas à terapia fotodinâmica, sendo observada total inibiçäo de crescimento para Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus e Lactobacillus casei. Os resultados sugerem que a terapia fotodinâmica é efetiva para a reduçäo de bactérias cariogênicas, in vitro, nos parâmetros testados

Análise de flúor em enxaguatórios bucais encontrados no comércio brasileiro e o uso de eletrodo íon-específico / Analysis of fluorine in mouthrinses found in the Brazilian marketplace and the utilization of an ion-specific electrode

A condiçäo mínima para que produtos comerciais tenham potencial anticárie é a presença de uma concentraçäo significativa de flúor solúvel nos mesmos. Considerando-se que essa condiçäo é inclusive regulamentada por lei, o presente trabalho teve por objetivo primário analisar as concentraçöes de íon flúor de sete marcas comerciais de enxaguatórios bucais. Para isso utilizou-se um eletrodo específico para flúor Orion 96-09 acoplado a um analisador de íons Orion EA 940, ambos previamente calibrados, sendo o objetivo secundário deste trabalho descrever operacionalmente a realizaçäo dessa análise. Os resultados encontrados (média ñ dp; n = 3) de íon flúor (ppm) foram: Kolynos Flúor© - 213,3 ñ 9,0; Fluordent© - 223,7 ñ 1,7; Plax Kids© - 229,1 ñ 3,8; Cepacol Júnior© - 218,6 ñ 1,1; Sorriso Herbal© - 220,6 ñ 6,5; Fresh Breath Menta© - 88,7 ñ 1,1; Fresh Breath Menta Azul© - 88,0 ñ 3,7. Os resultados mostraram que apenas os enxaguatórios da marca Fresh Breath estavam em desacordo com a Portaria nº 29 de 28 de agosto de 2000 da Agência Nacional de Vigilância Sanitária (Anvisa) do Ministério da Saúde do Brasil e que a técnica de análise com eletrodo íon-específico é precisa e exata