RESUMO
OBJECTIVES: To evaluate the mechanical and antimicrobial properties of boron-containing coating on translucent zirconia (5Y-PSZ). METHODS: 5Y-PSZ discs (Control) were coated with a glaze (Glaze), silver- (AgCoat), or boron-containing (BCoat) glasses. The coatings' antimicrobial potential was characterized using S. mutans biofilms after 48 h via viable colony-forming units (CFU), metabolic activity (CV) assays, and quantification of extracellular polysaccharide matrix (EPS). Biofilm architectures were imaged under scanning electron and confocal laser scanning microscopies (SEM and CLSM). The cytocompatibility was determined at 24 h via WST-1 and LIVE&DEAD assays using periodontal ligament stem cells (PDLSCs). The coatings' effects on properties were characterized by Vickers hardness, biaxial bending tests, and fractography analysis. Statistical analyses were performed via one-way ANOVA, Tukey's tests, Weibull analysis, and Pearson's correlation analysis. RESULTS: BCoat significantly decreased biofilm formation, having the lowest CFU and metabolic activity compared with the other groups. BCoat and AgCoat presented the lowest EPS, followed by Glaze and Control. SEM and CLSM images revealed that the biofilms on BCoat were thin and sparse, with lower biovolume. In contrast, the other groups yielded robust biofilms with higher biovolume. The cytocompatibility was similar in all groups. BCoat, AgCoat, and Glaze also presented similar hardness and were significantly lower than Control. BCoat had the highest flexural strength, characteristic strength and Weibull parameters (σF: 625 MPa; σ0: 620 MPa; m = 11.5), followed by AgCoat (σF: 464 MPa; σ0: 478 MPa; m = 5.3). SIGNIFICANCE: BCoat is a cytocompatible coating with promising antimicrobial properties that can improve the mechanical properties and reliability of 5Y-PSZ.
Assuntos
Anti-Infecciosos , Cerâmica , Teste de Materiais , Boro/farmacologia , Reprodutibilidade dos Testes , Zircônio/farmacologia , Propriedades de SuperfícieRESUMO
Dental biofilms represent a serious oral health problem playing a key role in the development of caries and other oral diseases. In the present work, we cloned and expressed in E. coli two glucanases, Prevotella melaninogenica mutanase (PmGH87) and Capnocytophaga ochracea dextranase (CoGH66), and characterized them biochemically and biophysically. Their three-dimensional structures were elucidated and discussed. Furthermore, we tested the capacity of the enzymes to hydrolyze mutan and dextran to prevent formation of Streptococcus mutans biofilms, as well as to degrade pre- formed biofilms in low and abundant sugar conditions. The percentage of residual biofilm was calculated for each treatment group in relation to the control, as well as the degree of synergism. Our results suggest that both PmGH87 and CoGH66 are capable of inhibiting biofilm formation grown under limited or abundant sucrose conditions. Degradation of pre-formed biofilms experiments reveal a time-dependent effect for the treatment with each enzyme alone. In addition, a synergistic and dose-dependent effects of the combined enzymatic treatment with the enzymes were observed. For instance, the highest biomass degradation was 95.5% after 30 min treatment for the biofilm grown in low sucrose concentration, and 93.8% after 2 h treatment for the biofilm grown in sugar abundant condition. Strong synergistic effects were observed, with calculated degree of synergism of 5.54 and 3.18, respectively and their structural basis was discussed. Jointly, these data can pave the ground for the development of biomedical applications of the enzymes for controlling growth and promoting degradation of established oral biofilms.
Assuntos
Escherichia coli , Prevotella melaninogenica , Escherichia coli/genética , Biofilmes , SacaroseRESUMO
Chitosan particles loaded with dibasic calcium phosphate anhydrous (DCPA) is a promising strategy for combining antimicrobial and osteoconduction properties in regenerative medicine. However, mostly micrometer-sized particles have been reported in the literature, limiting their use and reducing their effect in the biomedical field. We have recently overcome this limitation by developing submicrometer-sized particles with electrospray technique. The objective of this study was to understand how the process parameters control the size and properties of submicrometer chitosan particles loaded with DCPA. Solutions of 10 mg/mL chitosan and 2.5 mg/mL DCPA in a 90% acetic acid were electrosprayed under three distinct flow rate conditions: 0.2, 0.5, and 1.0 mL/h. The particles were crosslinked in a glutaraldehyde atmosphere and characterized in terms of their morphology, inorganic content, zeta potential, and minimum inhibitory concentration (MIC) against S. mutans. All conditions showed particles with two similar morphologies: one small-sized with a spherical shape and another larger-sized with a bi-concave shape. All generated a broad particle size distribution, with a similar mean size of ~ 235 nm. The addition of DCPA decreased the zeta potential for all the samples, but it was above 30 mV, indicating a low aggregation potential. The lower flow rate showed the worst efficacy for DCPA incorporation. Antimicrobial activity was greater in chitosan/DCPA particles with flow rate of 0.5 mL/h. It can be concluded that the flow rate of 0.5 mL/h presents the best compromise solution in terms of morphology, zeta potential, MIC, and inorganic content.
Assuntos
Anti-Infecciosos , Quitosana , Tamanho da Partícula , Fosfatos de Cálcio , Anti-Infecciosos/farmacologiaRESUMO
OBJECTIVES: To compare the biodegradability, mechanical behavior, and physicochemical features of the collagen-rich extracellular matrix (ECM) of artificial caries-affected dentin (ACAD), natural caries-affected dentin (NCAD) and sound dentin (SD). METHODS: Dentin specimens from human molars were prepared and assigned into groups according to the type of dentin: ACAD, NCAD, or SD. ACAD was produced by incubation of demineralized SD with Streptococcus mutans in a chemically defined medium (CDM) with 1% sucrose for 7 days at 37 °C under anaerobic conditions. Specimens were assessed to determine collagen birefringence, biodegradability, mechanical behavior, and chemical composition. Data were individually processed and analyzed by ANOVA and post-hoc tests (α = 0.05). RESULTS: CDM-based biofilm challenge reduced loss, storage, and complex moduli in ACAD (p < 0.001), while the damping capacity remained unaffected (p = 0.066). Higher red and lower green birefringence were found in ACAD and NCAD when compared with SD (p < 0.001). Differently to ACAD, SD and NCAD presented higher biodegradability to exogenous proteases (p = 0.02). Chemical analysis of the integrated areas of characteristic bands that assess mineral quality (carbonate/phosphate and crystallinity index), mineral to matrix (phosphate/amide I) and post-translational modifications (amide III/CH2, pentosidine/CH2, and pentosidine/amide III) (p<0.05) showed that NCAD was significantly different from SD while ACAD exhibited intermediate values. CONCLUSIONS: CDM-based biofilm challenge produced a dentin ECM with decreased mechanical properties and increased collagen maturity. The compositional and structural conformation of the ACAD suggested that CDM-based biofilm challenge showed potential to produce artificial lesions by revealing a transitional condition towards mimicking critical features of NCAD. CLINICAL SIGNIFICANCE: This study highlights the importance of developing a tissue that mimics the features of natural caries-affected dentin ECM for in vitro studies. Our findings suggested the potential of a modified biofilm challenge protocol to produce and simulate a relevant substrate, such as caries-affected dentin.
Assuntos
Cárie Dentária , Adesivos Dentinários , Humanos , Adesivos Dentinários/química , Dentina/química , Suscetibilidade à Cárie Dentária , Cárie Dentária/patologia , Colágeno/análise , Fosfatos , Amidas/análiseRESUMO
This study aimed at performing a systematic review of the literature on the effects of epigallocatechin-3-gallate (EGCG) on Streptococcus mutans planktonic cultures and biofilms. The selected references demonstrated that EGCG suppresses S. mutans acid production by inhibiting the activity of enzymes such as lactate dehydrogenase and FIF0-ATPase. Regarding virulence factors, one study reported a reduction in soluble and insoluble polysaccharide synthesis, another demonstrated that EGCG inhibited GTase activity, and another showed effects of EGCG on the expression of gtf B, C, and D. The effects of EGCG on S. mutans biofilms were reported only by 2 of the selected studies. Moreover, high variability in effective concentrations and microbial assessment methods were observed. The literature suggests that EGCG has effects against S. mutans planktonic cells viability and virulence factors. However, the literature lacks studies with appropriate biofilm models to evaluate the precise effectiveness of EGCG against S. mutans biofilms.
Assuntos
Catequina , Streptococcus mutans , Adenosina Trifosfatases/metabolismo , Adenosina Trifosfatases/farmacologia , Biofilmes , Catequina/análogos & derivados , Catequina/farmacologia , Lactato Desidrogenases/metabolismo , Plâncton/metabolismo , Polissacarídeos , Chá , Fatores de Virulência/metabolismoRESUMO
Background and Objectives: Streptococcus mutans (S. mutans) is the main microorganism associated with the presence of dental caries and specific serotypes of this bacteria have been related to several systemic diseases limiting general health. In orthodontics, white spot lesions (WSL), represent a great challenge for clinicians due to the great fluctuation of their prevalence and incidence during conventional orthodontic treatments. Although silver nanoparticles (AgNP) have been demonstrated to have great antimicrobial properties in several microorganisms, including S. mutans bacteria, there is no available information about anti adherence and antimicrobial properties of AgNP exposed to two of the most relevant serotypes of S. mutans adhered on orthodontic materials used for conventional therapeutics. The objective of this study was to determine anti-adherence and antimicrobial levels of AgNP against serotypes c and k of S. mutans on conventional orthodontic appliances. Materials and Methods: An AgNP solution was prepared and characterized using dispersion light scattering (DLS) and transmission electron microscopy (TEM). Antimicrobial and anti-adherence activities of AgNP were determined using minimal inhibitory concentrations (MIC) and bacterial adherence testing against serotypes c and k of S. mutans clinically isolated and confirmed by PCR assay. Results: The prepared AgNP had spherical shapes with a good size distribution (29.3 ± 0.7 nm) with negative and well-defined electrical charges (−36.5 ± 5.7 mV). AgNP had good bacterial growth (55.7 ± 19.3 µg/mL for serotype c, and 111.4 ± 38.6 µg/mL for serotype k) and adherence inhibitions for all bacterial strains and orthodontic wires (p < 0.05). The serotype k showed statistically the highest microbial adherence (p < 0.05). The SS wires promoted more bacterial adhesion (149.0 ± 253.6 UFC/mL × 104) than CuNiTi (3.3 ± 6.0 UFC/mL × 104) and NiTi (101.1 ± 108.5 UFC/mL × 104) arches. SEM analysis suggests CuNiTi wires demonstrated better topographical conditions for bacterial adherence while AFM evaluation determined cell wall irregularities in bacterial cells exposed to AgNP. Conclusions: This study suggests the widespread use of AgNP as a potential anti-adherent and antimicrobial agent for the prevention of WSL during conventional orthodontic therapies and, collaterally, other systemic diseases.
Assuntos
Anti-Infecciosos , Cárie Dentária , Nanopartículas Metálicas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/farmacologia , Anti-Infecciosos/uso terapêutico , Cárie Dentária/tratamento farmacológico , Humanos , Nanopartículas Metálicas/uso terapêutico , Aparelhos Ortodônticos , Sorogrupo , Prata/farmacologia , Prata/uso terapêutico , Streptococcus mutansRESUMO
BACKGROUND: This in vitro study aimed to evaluate the use of EDTA combined with photodynamic therapy to reduce Streptococcus mutans in carious dentin. METHODS: Sixty third molars were sectioned to obtain flat dentin surfaces. All specimens were waterproofed, except for the coronal dentin, and subjected to cariogenic challenge in brain-heart infusion (BHI) broth supplemented with 0.5% yeast extract, 1% glucose, 1% sucrose, and standard strain of S. mutans (ATCC 25175). The specimens were divided into 6 groups (n = 10 each): (1) control - caries collection; (2) EDTA - 17% EDTA was actively applied with a microbrush for 1 min; (3) aPDT - antimicrobial photodynamic therapy with 0.01% methylene blue photosensitizer (wavelength of 660 nm, energy of 4 J, power of 100 mW, spot size of 0.028 cm2, energy density of 142 J/cm2 for 40 s); (4) EDTA+aPDT - 17% EDTA actively applied for 1 min plus aPDT; (5) (EDTA+PT) + L - application of EDTA compounded with photosensitizer plus laser irradiation; and (6) PT - photosensitizer alone. Collection of caries was performed after the different cavity disinfection protocols. Aliquots from each dilution were seeded for colony-forming unit (CFU) counts. The results were log10-transformed and analyzed by the Kruskal-Wallis test (Student-Newman-Keuls). RESULTS: There was a significant reduction in S. mutans after aPDT (p<0.05), EDTA+aPDT (p<0.001), and (EDTA+PT) + L (p<0.001). The percentage of microbial reduction in ascending order was as follows: EDTA: 1.65%; PT: 15.51%; aPDT: 38.28%; EDTA+aPDT: 75.24%; and (EDTA+PT) + L: 97.35%. CONCLUSION: Application of 17% EDTA prior to photosensitization or compounded with a photosensitizer increased the antimicrobial effect of aPDT on S. mutans in carious dentin.
Assuntos
Cárie Dentária , Fotoquimioterapia , Biofilmes , Cárie Dentária/tratamento farmacológico , Ácido Edético/farmacologia , Humanos , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Streptococcus mutansRESUMO
Las extracciones quirúrgicas de terceros molares pueden, si no son atendidas oportunamente, conllevar infecciones postoperatorias de gravedad. Este estudio se realizó sobre una población de 103 pacientes provenientes de la Provincia de Chimborazo, Ecuador con el fin de estudiar posibles infecciones postoperativa después de la extracción de terceros molares. Para ello, se realizó la estratificación de la población en función de la edad (15 a 25, 26 a 30, 31 a 40, 41 a 50 y 51 a 60 años), sexo, estudios escolares (inicial, básica, bachiller y profesional) y nivel socioecónomico (bajo, medio y alto). A la par, se estudió la presencia de bacterias altamente patógenas como la S. mutans y P. gingivalis en la cavidad bucal de las personas con infección postoperatoria. Los resultados revelaron que las molestias asociadas a la extracción de estos terceros molares son más frecuentes entre la población de 15 a 30 años, y es la población femenina la más proclive a tales inflamaciones. Los pacientes de menores recursos económicos fueron lo que acudieron a estos centros asistencias asociados al bajo costo de los mismos. Al analizar la posición del tercer molar respecto al segundo se observó una mayor frecuencia en la posición B. Asimismo, se determinó la presencia de S. mutans y P. gingivali en más de la mitad de la población tratada que debe ser atendida en el menor tiempo posible a fin de evitar males mayores. Se hace un llamado a los padres de familia y maestros para que sea orientadores de estas enfermedades(AU)
Surgical extractions of third molars can, if not treated promptly, lead to serious postoperative infections. This study was conducted on a population of 103 patients from the Province of Chimborazo, Ecuador in order to study possible postoperative infections after the extraction of third molars. For this, the population was stratified according to age (15 to 25, 26 to 30, 31 to 40, 41 to 50 and 51 to 60 years), sex, school studies (initial, basic, high school and professional) and socioeconomic level (low, medium and high). At the same time, the presence of highly pathogenic bacteria such as S. mutans and P. gingivalis in the oral cavity of people with postoperative infection was studied. The results revealed that the discomfort associated with the extraction of these third molars is more frequent among the population aged 15 to 30 years, and the female population is the most prone to such inflammation. Patients with lower economic resources were the ones who attended these assistance centers associated with their low cost. When analyzing the position of the third molar regard to the second, a higher frequency was observed in position B. Likewise, the presence of S. mutans and P. gingivali was determined in more than half of the treated population that should be treated in the minor time possible in order to avoid greater problems. A call is made to parents and teachers to guide these diseases(AU)
Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Idoso , Cirurgia Bucal , Infecção da Ferida Cirúrgica , Extração Dentária , Dente Serotino , Classe Social , Bactérias , Ensino Fundamental e Médio , InfecçõesRESUMO
OBJECTIVE: Synthesize novel epigallocatechin-gallate (EGCG) methacrylate monomers with the ability to copolymerize with dental methacrylate resins. METHODS: EGCG was reacted with 1/3 (E33), 2/3 (E67) and 1 (E100) molar equivalents of methacyloyl chloride introducing three degrees of polymerizablility. EGCG-methacrylates were characterized by Fourier Transform Infrared Spectroscopy (FTIR) and Nuclear Magnetic Resonance (NMR). E33, E67, E100 and neat EGCG were incorporated into TEGDMA at 0.5-20% ratios (m/m). Copolymers were tested for degree of conversion (%DC), EGCG release, gel content (%GC), degree of swelling (%DS), flexural properties and bacterial viability (Streptococcus mutans, baseline/30-days). Neat TEGDMA and TEGDMA passively loaded with EGCG (E0) were used as controls. Data were analysed by one-way ANOVA, Tukey, and Dunnett's method (α=5%). Two-way ANOVA and Bonferroni were used to investigate factor interaction. RESULTS: FTIR/NMR confirmed synthesis of desired compounds. All of E100 incorporated ratios had %DC similar to TEGDMA. Remaining groups had reduction in %DC at 2% in E0, 10% in E33 and 20% in E67 ratios. EGCG was stable within ECGC-methacrylate copolymers. Release of EGCG from E0 significantly increased with higher EGCG ratios. Except for E100, higher EGCG or EGCG-methacrylate ratios led to decreased %CG and %DS. At baseline, E0 had the lowest bacterial survival rates (1-10% survival) at all ratios compared to E33, E67, E100, and neat TEGDMA. However, E33, E67 and E100 still had statistically lower survival rates (7-53%) compared with neat TEGDMA. After 30-days, all compounds had similar survival rates for all ratios, which were lower than that of neat TEGDMA. SIGNIFICANCE: Demonstration of methacrylate functionalized EGCG- with inherited antibacterial activity for improved restoration longevity.
Assuntos
Polímeros , Streptococcus mutans , Catequina/análogos & derivados , Teste de Materiais , PolimerizaçãoRESUMO
To evaluate the use of cetrimide alone and combined with photodynamic therapy to reduce S. mutans burden in carious lesions. Sixty permanent third molars were sectioned and the coronal dentin exposed. A cariogenic challenge was performed using brain-heart infusion (BHI) medium supplemented and S. mutans ATCC 25175. Specimens were incubated in anaerobic jars at 37 °C for 15 days, with BHI renewed every 24 h. After 15 days, specimens were randomly divided into six groups (n = 10): C, control (no treatment); CHX, application of chlorhexidine 2%; CT, application of cetrimide 2%; CT+aPDT, application of cetrimide 2% followed by methylene blue dye and aPDT (antimicrobial photodynamic therapy: wavelength 660 nm, energy 4J, power 100 mW, spot size 0.0028 cm2, energy density 142 J/cm2 for 40 s); ES+aPDT, application of experimental solution (methylene blue dye with cetrimide) and aPDT; and aPDT alone. 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 application of CT+aPDT (0.30 (0.97), p < 0.0001) and ES+aPDT (0.52 (1.13), p < 0.0001). Cetrimide 2% with methylene blue dye, applied consecutively or as a mixture, can be used as a photosensitizing agent for aPDT to reduce S. mutans burden in dentinal caries.
Assuntos
Cárie Dentária , Fotoquimioterapia , Cetrimônio , Cárie Dentária/tratamento farmacológico , Humanos , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêutico , Streptococcus mutansRESUMO
Though aloe vera extract, green tea extract and coriander oil are proven antimicrobial agents, very little information is available regarding its effects on oral bacteria, Streptococcus mutans, which is responsible for initiating caries and Enterococcus faecalis, responsible for failure of root canal treatment. Objective: To find the antimicrobial activity of aloe vera extract, black tea extract and coriander oil against S. mutans and E. faecalis. Materials and Methods: The agar well diffusion method was used to determine the antibacterial activity of Aloe vera extract, black tea extract and coriander oil. Different concentration of prepared plant extracts and coriander seed oil (50 & 100 µl) was incorporated into the wells and the plates containing S. mutans and E. faecalis were incubated at 37 °C for 24 h. The antibiotic (amoxicillin 30 µl) was used as positive control. Zone Of Inhibition (ZOI) was recorded in each plate. Results: For S. mutans, the maximum ZOI was created by coriander oil with a diameter of 25.00±0.58 mm at 50 µl and for E. faecalis, maximum ZOI was created by aloe vera extract 16.00±0.58 mm at 100 µl concentration which were far better than the control: amoxicillin 30 µl concentration. Conclusion: The extracts of Aloe vera, black tea and coriander oil, showed significant activity against the investigated microbial strains, Streptococcus mutans and Enterococcus faecalis which further helps in the development of new topical agents that help in reducing the numbers of these organisms present in the oral cavity. (AU)
Embora o extrato de aloe vera, extrato de chá verde e óleo de coentro sejam agentes antimicrobianos comprovados, há pouca informação disponível sobre seus efeitos nas bactérias orais, Streptococcus mutans, que é responsável por iniciar cáries e Enterococcus faecalis, responsável pela falha do tratamento de canal radicular. Objetivo: Avaliar a atividade antimicrobiana do extrato de aloe vera, extrato de chá preto e óleo de coentro contra S. mutans e E. faecalis. Materiais e Métodos: O método de difusão em agar foi usado para determinar a atividade antibacteriana do extrato de Aloe vera, extrato de chá preto e óleo de coentro. Diferentes concentrações dos extratos de plantas e óleo de semente de coentro (50 e 100 µl) foram preparados e colocados nos poços e nas placas contendo S. mutans e E. faecalis e foram incubadas a 37°C por 24 h. O antibiótico (amoxicilina 30 µl) foi utilizado como controle positivo. A zona de inibição (ZOI) foi registrada em cada placa. Resultados: Para S. mutans, a ZOI máxima foi obtida com o óleo de coentro com um diâmetro de 25,00 ± 0,58 mm a 50 µl e para E. faecalis, a ZOI máxima foi obtiada pelo extrato de aloe vera 16,00 ± 0,58 mm na concentração de 100 µl, as quais foram melhores do que o controle: concentração de 30 µl de amoxicilina. Conclusão: Os extratos de Aloe vera, chá preto e óleo de coentro apresentaram atividade significativa contra as cepas microbianas investigadas, Streptococcus mutans e Enterococcus faecalis auxiliando no desenvolvimento de novos agentes tópicos visando a redução do número desses organismos presentes no cavidade oral. (AU)
Assuntos
Streptococcus mutans , Chá , Enterococcus faecalis , Aloe , MicrobiotaRESUMO
The study of bacterial interaction between Streptococcus mutans and Actinomyces naeslundii may disclose important features of biofilm interspecies relationships. The aim of this study was to characterize-with an emphasis on biofilm formation and composition and metabolic activity-single- and dual-species biofilms of S. mutans or A. naeslundii, and to use a drip flow reactor (DFR) to evaluate biofilm stress responses to 0.2% chlorhexidine diacetate (CHX). Single- and dual-species biofilms were grown for 24 h. The following factors were evaluated: cell viability, biomass and total proteins in the extracellular matrix, 2,3-bis(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide-"XTT"-reduction and lactic acid production. To evaluate stress response, biofilms were grown in DFR. Biofilms were treated with CHX or 0.9% sodium chloride (NaCl; control). Biofilms were plated for viability assessment. Confocal laser-scanning microscopy (CLSM) was also performed. Data analysis was carried out at 5% significance level. S. mutans viability and lactic acid production in dual-species biofilms were significantly reduced. S. mutans showed a higher resistance to CHX in dual-species biofilms. Total protein content, biomass and XTT reduction showed no significant differences between single- and dual-species biofilms. CLSM images showed the formation of large clusters in dual-species biofilms. In conclusion, dual-species biofilms reduced S. mutans viability and lactic acid production and increased S. mutans' resistance to chlorhexidine.
RESUMO
CONTEXT: Hydroxyapatite has shown to regenerate the mineralized layer of dentin, whereas the combination of the enzymes lysozyme, lactoferrin, and lactoperoxidase may exhibit antimicrobial properties against oral pathogens. AIMS: To evaluate a combination of hydroxyapatite and lysozyme, lactoferrin, and lactoperoxidase for the treatment of dentinal caries by measuring viable Streptococcus mutans. SETTINGS AND DESIGN: Laboratory study with experimental groups. METHODS AND MATERIAL: Carious lesions in 20 permanent third molars were treated with a combination of hydroxyapatite and the enzymes lysozyme, lactoferrin, and lactoperoxidase. Carious dentin was collected and homogenized in a vortex shaker. After homogenization, five decimal dilutions were performed. Three aliquots of 25 µL of each dilution were seeded onto the surface of mitis salivarius bacitracin (MSB) medium. All plates were incubated in anaerobic jars. After incubation, the viable bacterial count was determined. S. mutans counts were obtained before and 24 h, 1 month, and 6 months after treatment. STATISTICAL ANALYSIS USED: Descriptive statistical analysis and the Kruskal-Wallis test, supplemented by the Student-Newman-Keuls test. RESULTS: A significant reduction in S. mutans counts was observed 24 h after sealing with a combination of hydroxyapatite, lysozyme, lactoferrin, and lactoperoxidase as compared to counts after 1 month and after 6 months (P < 0.05). CONCLUSIONS: The combination of hydroxyapatite with lysozyme, lactoferrin, and lactoperoxidase may be an alternative for S. mutans control in dentinal caries.
Assuntos
Anti-Infecciosos , Cárie Dentária , Cárie Dentária/tratamento farmacológico , Suscetibilidade à Cárie Dentária , Durapatita , Humanos , Lactoferrina , Lactoperoxidase , Muramidase , Streptococcus mutansRESUMO
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.
Assuntos
Condicionamento Ácido do Dente , Cárie Dentária/tratamento farmacológico , Cárie Dentária/microbiologia , Fotoquimioterapia , Fármacos Fotossensibilizantes/uso terapêutico , Streptococcus mutans/efeitos dos fármacos , Contagem de Colônia Microbiana , Humanos , Luz , Streptococcus mutans/crescimento & desenvolvimento , Streptococcus mutans/efeitos da radiaçãoRESUMO
Abstract Although resin composites are widely used in the clinical practice, the development of recurrent caries at composite-tooth interface still remains as one of the principal shortcomings to be overcome in this field. Objectives To evaluate the activity against S. mutans biofilm of model resin composites incorporating different concentrations of ZnO-nanoparticles (ZnO-NP) and characterize their physicochemical properties. Materials and Methods Different concentrations of ZnO-NP (wt.%): E1=0, E2=0.5, E3=1, E4=2, E5=5 and E6=10 were incorporated into a model resin composite consisting of Bis-GMA-TEGDMA and barium borosilicate particles. The activity against S. mutans biofilm was evaluated by metabolic activity and lactic acid production. The following physicochemical properties were characterized: degree of conversion (DC%), flexural strength (FS), elastic modulus (EM), hardness (KHN), water sorption (Wsp), water solubility (Wsl) and translucency (TP). Results E3, E4, E5 and E6 decreased the biofilm metabolic activity and E5 and E6 decreased the lactic acid production (p<0.05). E6 presented the lowest DC% (p<0.05). No significant difference in FS and EM was found for all resin composites (p>0.05). E5 and E6 presented the lowest values of KHN (p<0.05). E6 presented a higher Wsp than E1 (p<0.05) and the highest Wsl (p<0.05). The translucency significantly decreased as the ZnO- NP concentration increased (p<0.05). Conclusions The incorporation of 2 - 5 wt.% of ZnO-NP could endow antibacterial activity to resin composites, without jeopardizing their physicochemical properties.
Assuntos
Streptococcus mutans/efeitos dos fármacos , Óxido de Zinco/farmacologia , Óxido de Zinco/química , Resinas Compostas/farmacologia , Resinas Compostas/química , Nanopartículas/química , Polietilenoglicóis/farmacologia , Polietilenoglicóis/química , Ácidos Polimetacrílicos/farmacologia , Ácidos Polimetacrílicos/química , Valores de Referência , Solubilidade , Streptococcus mutans/crescimento & desenvolvimento , Propriedades de Superfície , Teste de Materiais , Água/química , Microscopia Eletrônica de Varredura , Modelos Lineares , Reprodutibilidade dos Testes , Análise de Variância , Bis-Fenol A-Glicidil Metacrilato/farmacologia , Bis-Fenol A-Glicidil Metacrilato/química , Silicatos/farmacologia , Silicatos/química , Compostos de Bário/farmacologia , Compostos de Bário/química , Maleabilidade , Biofilmes/crescimento & desenvolvimento , Biofilmes/efeitos dos fármacos , Módulo de Elasticidade , Testes de DurezaRESUMO
Objetivo: evaluar la actividad antimicrobiana de cinamaldehído, timol, eugenol y quitosano en comparación con clorhexidina al 0,12 por ciento sobre cepas de Streptococccus mutans. Métodos: se realizaron pruebas de susceptibilidad bacteriana de cepas de Streptococccus mutans con discos embebidos en eugenol, cinamaldehído, quitosano y timol, al 0,1 y 1 por ciento con un control positivo de clorhexidina al 0,12 por ciento evaluando los halos de inhibición existentes a las 24 h y 48 h. Resultados: el cinamaldehído al 1 por ciento mostró el mejor poder de control sobre el crecimiento de Streptococccus mutans al presentar 19,91 mm y 24,44 mm de halos de inhibición a las 24 h y 48 h, respectivamente, con una diferencia significativa de p< 0,05 entre los dos intervalos. Cuando se comparó el cinamaldehído al 1 por ciento con el control positivo de clorhexidina al 0,12 por ciento, no se encontraron diferencias significativas (p> 0,05). Conclusiones: el cinamaldehído al 1 por ciento tuvo los mejores resultados seguidos por quitosano, eugenol y timol a la misma concentración en comparación con clorhexidina al 0,12 por ciento tanto a la 24 como 48 h(AU)
Objective: to evaluate the antimicrobial activity of cinnamaldehyde, thymol, eugenol and chitosan compared to chlorhexidine-0.12 percent on Streptococcus mutans strains. Methods: bacterial susceptibility tests were performed on S. mutans strains with disks embedded in eugenol, cinnamaldehyde, chitosan and thymol, at 0.1 percent and 1 percent with a positive control of 0.12 percent chlorhexidine, evaluating existing inhibition zones after 24 and 48 hours. Results: cinnamaldehyde-1 percent showed the best control power over the growth of S. mutans, presenting 19.91 mm and 24.44 mm of inhibition halos after 24 and 48 hours, respectively, with a significant difference of p< 0.05 between the two intervals. When the cinnamaldehyde-1 percent was compared with the positive control of chlorhexidine-0.12 percent, no significant differences were found (p> 0.05). Conclusions: cinnamaldehyde-1 percent had the best results followed by chitosan, eugenol and thymol in the same concentration compared to chlorhexidine-0.12 percent after both 24 and 48 hours(AU)
Assuntos
Humanos , Cárie Dentária/diagnóstico , Eugenol/uso terapêutico , Streptococcus mutans , Timol/uso terapêutico , Suscetibilidade à Cárie Dentária , Epidemiologia Descritiva , Ensaio Clínico , Estudo ObservacionalRESUMO
Abstract: The purpose of this study was to evaluate the antimicrobial properties of a new formulation containing silver nanoparticles, named Nano Silver Fluoride (NSF), to inhibit Streptococcus mutans biofilm formation on children's dental enamel. The variations in dental biofilm pH and in the Simplified-Oral-Hygiene-Index (OHI-S) also were evaluated after the treatment with NSF. This was a randomized, double-blind, crossover and prospective pilot clinical trial study in which 12 schoolchildren, aged between 7-8 years, had their dental enamel treated with two solutions: S1 - Nano Silver Fluoride and S2 - negative control (saline solution), in different experimental moments. The dental biofilm adhered to enamel treated with NSF had lower values of S. mutans viability (absorbance) and colony forming units (CFU) than the S0 (baseline) and S2. There was a statistically significant difference between the OHI-S mean values of S0 and S1. There were no differences between the biofilm pH (both before and after the use of the test substances) and among the different groups. These properties suggest that NSF has bactericidal effect against S. mutans biofilm and it may be used for clinical control and prevention of dental biofilm formation.
Resumo O objetivo do presente estudo foi avaliar as propriedades antimicrobianas de uma nova formulação composta por nanopartículas de prata, denominada nano silver fluoride (NSF), na inibição de biofilme de Streptococcus mutans sobre a superfície do esmalte dentário de crianças. Variações no pH do biofilme dental e nos valores do índice de Higiene Oral Simplificada (IHO-S) também foram avaliadas após o tratamento com NSF. Trata-se de um estudo piloto, randomizado, duplo cego, cruzado e prospectivo. A amostra foi composta por 12 crianças, de ambos os gêneros, com idades entre 7 e 8 anos, as quais utilizaram as duas soluções testes, S1- NSF e S2- controle negativo (solução salina). O biofilme dental tratado com NSF apresentou menores valores de viabilidade de S. mutans (absorbância) e de unidades formadoras de colônias (UFC) do que o biofilme baseline e o biofilme tratado com S2. Houve diferença estatisticamente significativa entre os valores médios de IHO-S dos grupos baseline e S1, com uma redução dos valores. Não houve qualquer variação nos valores de pH do biofilme dental, antes e depois do tratamento com S1 e S2 e entre os diferentes grupos. Estas propriedades sugerem que NSF possui efeito bactericida sobre o biofilme de S. mutans, podendo ser utilizado clinicamente para o controle e prevenção da formação do biofilme dentário.
Assuntos
Humanos , Masculino , Feminino , Criança , Biofilmes , Nanopartículas Metálicas/química , Prata/química , Streptococcus mutans/efeitos dos fármacos , Contagem de Colônia Microbiana , Estudos Cross-Over , Método Duplo-Cego , Concentração de Íons de Hidrogênio , Índice de Higiene Oral , Projetos Piloto , Estudos Prospectivos , Streptococcus mutans/fisiologiaRESUMO
Abstract The aim of this study was to evaluate the μTBS in different dentin substrates and water-storage periods. Twenty-four dentin blocks obtained from sound third molars were randomly divided into 3 groups: Sound dentin (Sd), Caries-affected dentin (Ca) and Caries-infected dentin (Ci). Dentin blocks from Ca and Ci groups were subjected to artificial caries development (S. mutans biofilm). The softest carious tissue was removed using spherical drills under visual inspection with Caries Detector solution (Ca group). It was considered as Ci (softer and deeply red stained dentin) and Ca (harder and slightly red stained dentin). The Adper Single Bond 2 adhesive system was applied and Z350 composite blocks were built in all groups. Teeth were stored in deionized water for 24 h at 37 ºC and sectioned into beams (1.0 mm2 section area). The beams from each tooth were randomly divided into three storages periods: 24 h, 6 months or 1 year. Specimens were submitted to µTBS using EZ test machine at a crosshead speed of 1.0 mm/min. Failure mode was examined by SEM. Data from µTBS were submitted to split plot two-way ANOVA and Tukey’s HSD tests (a=0.05). The µTBS (MPa) of Sd (41.2) was significantly higher than Ca (32.4) and Ci (27.2), regardless of storage. Ca and Ci after 6 months and 1 year, presented similar µTBS. Mixed and adhesive failures predominated in all groups. The highest µTBS values (48.1±9.1) were found for Sd at 24 h storage. Storage of specimens decreased the µTBS values for all conditions.
Resumo O objetivo neste estudo foi avaliar a resistência de união à microtração (RUµT) de um sistema adesivo convencional (Adper Single Bond 2 - SB) em diferentes substratos dentinários e períodos de armazenagem. Vinte e quatro blocos de dentina foram obtidos de terceiros molares hígidos e separados aleatoriamente em 3 grupos (n=8): dentina sadia (Ds), dentina afetada (Da) e dentina infectada (Di). A Da e a Di foram submetidas ao desenvolvimento biológico artificial de cárie (S. mutans). O tecido cariado amolecido foi removido usando broca esférica sob inspeção visual com a solução Caries Detector (grupo Da). Considerou-se como Di a dentina amolecida e fortemente pigmentada de vermelho e como Da, a dentina hígida e levemente pigmentada de vermelho. O sistema adesivo SB foi aplicado de acordo com as recomendações do fabricante e blocos da resina composta Z350 foram construídos (6 mm de altura). O conjunto (dente/bloco de resina) foi armazenado em água deionizada por 24 horas a 37 °C. Estes foram seccionados em palitos (1,0 mm2 de área), que foram separados aleatoriamente em 3 períodos de armazenagem: 24 horas, 6 meses e 1 ano. Os palitos foram submetidos ao ensaio de resistência de união à microtração na máquina EZ teste a uma velocidade de 1,0 mm/min. Dados de RUµT foram submetidos à Análise de Variância 2 fatores em esquema de parcela subdividida e ao teste de Tukey (a=0,05). Os valores de resistência (MPa) da Ds (41,2) foram significativamente maiores do que os da Da (32,4) e Di (27,2), independente do tempo de armazenagem. Di e Da, 6 meses e 1ano, apresentaram valores similares de resistência de união. As falhas adesivas e mistas foram predominantes para todos os grupos. Em conclusão, os maiores valores de RUµT (48,1±9,1) foram verificados para a Ds e 24 h de armazenagem. A armazenagem diminuiu os valores de RUµT para todas as condições.
Assuntos
Adesivos Dentinários , Cárie Dentária , Dentina , Resistência à Tração , Técnicas In Vitro , Microscopia Eletrônica de Varredura , Análise do Modo e do Efeito de Falhas na Assistência à Saúde , Dente SerotinoRESUMO
ABSTRACT Introduction: the objective of this study was to use real-time qPCR to identify and quantify the Streptococcus mutans species in samples of saliva and dental biofilm. Methods: 27 children were randomly chosen with the following criteria: 8 years of age, low socio-economic levels, residing in the northern metropolitan area of Santiago de Chile; they were asked to attend an appointment while fasting with no teeth brushing for at least 12 hours, in order to collect non-stimulated saliva and a pool of supragingival dental biofilm of all the mesio-vestibular sides of anterior and posterior teeth. The amount of S. mutans in the samples was quantified by qPCR using primers that amplify a fragment of the gtfB gene of S. mutans. Results: the amplification showed 98% efficiency with a fluorescence of 3.36 cycles. The melting curve presented a single maximum at the same temperature for all samples. Conclusion: the methodology allows the specific identification and quantification of gene gtfB of S. mutans in saliva and dental biofilm in a quick and reliable manner, contributing to the identification of individual cariogenic risk.
RESUMEN. Introducción: el objetivo del presente estudio consistió en implementar la técnica de qPCR en tiempo real para identificar y cuantificar la especie Streptococcus mutans en muestras de saliva y biopelícula dentaria. Métodos: se seleccionaron al azar 27 niños de 8 años de edad, de nivel socio-económico bajo del área norte de la región metropolitana de Santiago de Chile, que se citaron en ayunas y sin cepillado durante al menos 12 horas, para colectar saliva no estimulada y un pool de biopelícula dentaria supragingival de todas las caras mesio-vestibulares de dientes anteriores y posteriores. Se cuantificó la cantidad de S. mutans en las muestras mediante qPCR empleando partidores que amplifican un fragmento del gen gtfB de S. mutans. Resultados: la amplificación presentó 98% de eficiencia con delta de fluorescencia de 3,36 ciclos. La curva de fusión (melting) presentó un solo máximo a una misma temperatura para todas las muestras. Conclusión: la metodología permite la identificación y cuantificación específica del gen gtfB de S. mutans en muestras de saliva y biopelícula dentaria, de forma rápida y exacta, aportando a la determinación del riesgo cariogénico individual.
Assuntos
Placa Dentária , Saliva , Streptococcus , CriançaRESUMO
OBJECTIVE: Explore the associations between the severity of dental caries in childhood, mutans streptococci (MS) levels and IgA antibody response against Streptococcus mutans GbpB. Moreover, other caries-related etiological factors were also investigated. DESIGN: 36-60 month-old children were grouped into Caries-Free (CF, n=19), Early Childhood Caries (ECC, n=17) and Severe Early Childhood Caries (S-ECC, n=21). Data from socio-economic-cultural status, oral hygiene habits and dietary patterns were obtained from a questionnaire and a food-frequency diary filled out by parents. Saliva was collected from children for microbiological analysis and detection of salivary IgA antibody reactive with S. mutans GbpB in western blot. RESULTS: S-ECC children had reduced family income compared to those with ECC and CF. There was difference between CF and caries groups (ECC and S-ECC) in MS counts. Positive correlations between salivary IgA antibody response against GbpB and MS counts were found when the entire population was evaluated. When children with high MS counts were compared, S-ECC group showed significantly lower IgA antibody levels to GbpB compared to CF group. This finding was not observed for the ECC group. CONCLUSIONS: This study suggests that children with S-ECC have reduced salivary IgA immune responses to S. mutans GbpB, potentially compromising their ability to modify MS infection and its cariogenic potential. Furthermore, a reduced family income and high levels of MS were also associated with S-ECC.