RESUMO
INTRODUCTION: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. METHODS: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. RESULTS: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. CONCLUSIONS: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.
Assuntos
Antibacterianos/farmacologia , Resinas Compostas/farmacologia , Colagem Dentária , Nanopartículas , Titânio/farmacologia , Animais , Antibacterianos/análise , Bovinos , Resinas Compostas/química , Esmalte Dentário/microbiologia , Incisivo/microbiologia , Braquetes Ortodônticos , Resistência ao Cisalhamento , Streptococcus mutans/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Titânio/análiseRESUMO
ABSTRACT Introduction: Plaque accumulation and bond failure are drawbacks of orthodontic treatment, which requires composite for bonding of brackets. As the antimicrobial properties of TiO2 nanoparticles (NPs) have been proven, the aim of this study was to evaluate the antimicrobial and mechanical properties of composite resins modified by the addition of TiO2 NPs. Methods: Orthodontics composite containing 0%, 1%, 5% and 10% NPs were prepared. 180 composite disks were prepared for elution test, disk agar diffusion test and biofilm inhibition test to collect the counts of microorganisms on three days, measure the inhibition diameter and quantify the viable counts of colonies consequently. For shear bond strength (SBS) test, 48 intact bovine incisors were divided into four groups. Composites containing 0%, 1%, 5% and 10% NPs were used for bonding of bracket. The bracket/tooth SBS was measured by using an universal testing machine. Results: All concentration of TiO2 NPs had a significant effect on creation and extension of inhibition zone. For S. mutans and S. sanguinis, all concentration of TiO2 NPs caused reduction of the colony counts. Composite containing 10% TiO2 NPs had significant effect on reduction of colony counts for S. mutans and S. sanguinis in all three days. The highest mean shear bond strength belonged to the control group, while the lowest value was seen in 10% NPs composite. Conclusions: Incorporating TiO2 nanoparticles into composite resins confer antibacterial properties to adhesives, while the mean shear bond of composite containing 1% and 5% NPs still in an acceptable range.
RESUMO Introdução: o acúmulo de placa e as descolagens de braquetes são algumas desvantagens presentes no tratamento ortodôntico, no qual se requer o uso de materiais compósitos para a colagem dos braquetes. Objetivo: tendo em vista que as propriedades antimicrobianas das nanopartículas (NPs) de TiO2 já foram confirmadas, o objetivo do presente estudo foi avaliar as propriedades antimicrobianas e mecânicas de resinas compostas modificadas pela adição de NPs de TiO2. Métodos: compósitos ortodônticos contendo 0%, 1%, 5% e 10% de NPs foram preparados. Cento e oitenta discos de compósito foram preparados para o teste de eluição, o ensaio de difusão em ágar por disco, e o ensaio de inibição da formação de biofilme, para se calcular as contagens de microrganismos ao longo de três dias, medir o diâmetro da inibição e, consequentemente, quantificar as contagens de colônias viáveis. Para o teste de resistência da colagem ao cisalhamento (SBS), 48 incisivos bovinos intactos foram divididos em quatro grupos, nos quais os compósitos contendo 0%, 1%, 5% e 10% de NPs foram utilizados para colagem dos braquetes. A SBS da interface braquete/dente foi medida em uma máquina universal de ensaios. Resultados: todas as concentrações de NPs de TiO2 apresentaram efeito significativo na formação e na extensão da zona de inibição. Para o S. mutans e o S. sanguinis, todas as concentrações de NPs de TiO2 causaram redução na contagem das colônias. O compósito contendo 10% de NPs de TiO2 apresentou uma diminuição significativa na contagem de colônias de S. mutans e S. sanguinis durante os três dias. A média mais alta da SBS foi observada no grupo controle, enquanto o valor mais baixo foi observado para o compósito com 10% de NPs. Conclusões: a incorporação de nanopartículas de TiO2 nas resinas compostas lhes conferiu propriedades antibacterianas, e o valor médio da SBS das resinas contendo 1% e 5% de NPs apresentou-se dentro de uma faixa aceitável.
Assuntos
Animais , Titânio/farmacologia , Colagem Dentária , Resinas Compostas/farmacologia , Nanopartículas , Antibacterianos/farmacologia , Streptococcus mutans/efeitos dos fármacos , Streptococcus sanguis/efeitos dos fármacos , Titânio/análise , Bovinos , Braquetes Ortodônticos , Resinas Compostas/química , Esmalte Dentário/microbiologia , Resistência ao Cisalhamento , Incisivo/microbiologia , Antibacterianos/análiseRESUMO
This study was conducted to evaluate if extracellular polysaccharides (EPS) are used by Streptococcus mutans (Sm) biofilm during night starvation, contributing to enamel demineralization increasing occurred during daily sugar exposure. Sm biofilms were formed during 5 days on bovine enamel slabs of known surface hardness (SH). The biofilms were exposed to sucrose 10% or glucose + fructose 10.5% (carbohydrates that differ on EPS formation), 8x/day but were maintained in starvation during the night. Biofilm samples were harvested during two moments, on the end of the 4th day and in the morning of the 5th day, conditions of sugar abundance and starvation, respectively. The slabs were also collected to evaluate the percentage of surface hardness loss (%SHL). The biofilms were analyzed for EPS soluble and insoluble and intracellular polysaccharides (IPS), viable bacteria (CFU), biofilm architecture and biomass. pH, calcium and acid concentration were determined in the culture medium. The data were analyzed by two-way ANOVA followed by Tukey's test or Student's t-test. The effect of the factor carbohydrate treatment for polysaccharide analysis was significant (p < 0.05) but not the harvest moment (p > 0.05). Larger amounts of soluble and insoluble EPS and IPS were formed in the sucrose group when compared to glucose + fructose group (p < 0.05), but they were not metabolized during starvation time (S-EPS, p = 0.93; I-EPS, p = 0.11; and IPS = 0.96). Greater enamel %SHL was also found for the sucrose group (p < 0.05) but the demineralization did not increase during starvation (p = 0.09). In conclusion, the findings suggest that EPS metabolization by S. mutans during night starvation do not contribute to increase enamel demineralization occurred during the daily abundance of sugar.
Assuntos
Biofilmes , Esmalte Dentário/microbiologia , Polissacarídeos/metabolismo , Streptococcus mutans/metabolismo , Desmineralização do Dente/microbiologia , Análise de Variância , Animais , Biofilmes/crescimento & desenvolvimento , Cálcio/metabolismo , Bovinos , Esmalte Dentário/metabolismo , Espaço Extracelular/metabolismo , Espaço Extracelular/microbiologia , Frutose/farmacologia , Glucose/farmacologia , Dureza , Concentração de Íons de Hidrogênio , Técnicas In Vitro , Incisivo/metabolismo , Incisivo/microbiologia , Microscopia Confocal , Streptococcus mutans/crescimento & desenvolvimento , Sacarose/farmacologia , Desmineralização do Dente/metabolismoRESUMO
OBJECTIVE: This study investigated the anti-demineralizing and antibacterial effects of a propolis ethanolic extract (EEP) against Streptococcus mutans dental biofilm. DESIGN: Blocks of sound bovine enamel (n=24) were fixed on polystyrene plates. S. mutans inoculum (ATCC 25175) and culture media were added (48 h-37 °C) to form biofilm. Blocks with biofilm received daily treatment (30 µL/1 min), for 5 days, as following: G1 (EEP 33.3%); G2 (chlorhexidine digluconate 0.12%); G3 (ethanol 80%); and G4 (Milli-Q water). G5 and G6 were blocks without biofilm that received only EEP and Milli-Q water, respectively. Final surface hardness was evaluated and the percentage of hardness loss (%HL) was calculated. The EEP extract pH and total solids were determined. S. mutans count was expressed by log10 scale of Colony-Forming Units (CFU/mL). One way ANOVA was used to compare results which differed at a 95% significance level. RESULTS: G2 presented the lowest average %HL value (68.44% ± 12.98) (p=0.010), while G4 presented the highest (90.49% ± 5.38%HL) (p=0.007). G1 showed %HL (84.41% ± 2.77) similar to G3 (87.80% ± 6.89) (p=0.477). Groups G5 and G6 presented %HL=16.11% ± 7.92 and 20.55% ± 10.65; respectively (p=0.952). G1 and G4 differed as regards to S. mutans count: 7.26 ± 0.08 and 8.29 ± 0.17 CFU/mL, respectively (p=0.001). The lowest bacterial count was observed in chlorhexidine group (G2=6.79 ± 0.10 CFU/mL) (p=0.043). There was no difference between S. mutans count of G3 and G4 (p=0.435). The EEP showed pH 4.8 and total soluble solids content=25.9 Brix. CONCLUSION: The EEP seems to be a potent antibacterial substance against S. mutans dental biofilm, but presented no inhibitory action on the de-remineralization of caries process.
Assuntos
Biofilmes/efeitos dos fármacos , Esmalte Dentário/efeitos dos fármacos , Própole/farmacologia , Streptococcus mutans/efeitos dos fármacos , Desmineralização do Dente/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos , Abelhas , Biofilmes/crescimento & desenvolvimento , Bovinos , Células Cultivadas , Clorexidina/farmacologia , Ácidos Cumáricos/química , Cárie Dentária/prevenção & controle , Esmalte Dentário/química , Dureza/efeitos dos fármacos , Concentração de Íons de Hidrogênio , Incisivo/química , Incisivo/efeitos dos fármacos , Incisivo/microbiologia , Própole/química , Streptococcus mutans/fisiologia , Propriedades de Superfície , Desmineralização do Dente/prevenção & controleRESUMO
The purpose of this study was to evaluate in vitro the effectiveness of two endodontic irrigants and their association against Enterococcus faecalis (E. faecalis) by confocal laser scanning microscope (CLSM). Twenty-four bovine incisors were inoculated in a monoculture of E. faecalis for 21 days. After this period, the teeth were divided into three test groups (n = 5) according to the chemical used. Group 1: 2.5% sodium hypochlorite (NaOCl), group 2: 2% chlorhexidine gel (CHX), group 3: 2.5% NaOCl + 2% CHX gel, and two control groups (n = 3): negative control group (NCG)-sterile and without root canals preparation and positive control group (PCG)-saline. Then, the samples were stained with SYTO9 and propidium iodide and subjected to analysis by CLSM. Bacterial viability was quantitatively analyzed by the proportions of dead and live bacteria in the biofilm remnants. Statistical analysis was performed by the One-way ANOVA test (p = 0.05). No statistical differences were observed to bacterial viability. According to CLSM analysis, none of the tested substances could completely eliminate E. faecalis from the root canal space. Until now, there are no irrigant solutions able to completely eliminate E. faecalis from the root canal. In this regard, the search for irrigants able to intensify the antimicrobial action is of paramount importance.
Assuntos
Biofilmes/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/fisiologia , Incisivo/microbiologia , Microscopia Confocal , Irrigantes do Canal Radicular/administração & dosagem , Animais , Bovinos , Viabilidade Microbiana/efeitos dos fármacos , Compostos Orgânicos , Propídio , Coloração e RotulagemRESUMO
AIM: To assess the effect of the daily ingestion of a mixture of probiotics on the amount of Streptococcus mutans in the oral cavity of preschool-age patients with a high risk of caries. MATERIALS AND METHODS: Forty patients, aged between 4 and 6 years, with a high risk of dental caries were included in this pilot study. Patients were randomly assigned to two study groups: the Experimental Group (A) included patients who brushed their teeth and used fluoridated toothpaste in addition to consuming probiotics daily, and the Control Group (B) inclused patients who brushed their teeth and used fluoridated toothpaste but did not consume probiotics. Using the CariScreen, the microorganism count was determined at different times: baseline, 7, 14, 21 and 30 days. To identify the differences between both groups, a Mann-Whitney U test was performed, with a significance level of 0.05. RESULTS: It was observed that both groups showed similar microbial counts at the beginning of the trial (p>0.05), and a significant decrease in the count at the end of the study was found in the experimental group (p<0.05) 15 days after suspending ingestion. CONCLUSION: We found a significant reduction of RLU values in preschool children who ingested the tested probiotics in relation to the baseline values and 15 days after ceasing consumption.
Assuntos
Boca/microbiologia , Probióticos/uso terapêutico , Streptococcus mutans/efeitos dos fármacos , Carga Bacteriana/efeitos dos fármacos , Cariostáticos/uso terapêutico , Criança , Pré-Escolar , Suscetibilidade à Cárie Dentária/efeitos dos fármacos , Feminino , Fluoretos/uso terapêutico , Seguimentos , Humanos , Incisivo/microbiologia , Masculino , Dente Molar/microbiologia , Projetos Piloto , Placebos , Streptococcus/classificação , Streptococcus oralis/fisiologia , Escovação Dentária/métodos , Cremes Dentais/uso terapêuticoRESUMO
OBJECTIVE: This in vitro study evaluated the effect of different endodontic auxiliary chemical substances over Enterococcus faecalis (Ef) biofilm through confocal laser scanning microscopy (CLSM). METHODS: Forty-five bovine incisors were infected with Ef for 21 days. Teeth were divided into five groups: group 1: 2.5% NaOCl + EDTA, group 2: 2% CHX gel + EDTA, group 3: 2% CHX liquid + EDTA, group 4: 2.5% NaOCl + 2% CHX gel + EDTA, group 5: 2.5% NaOCl + 2% CHX liquid + EDTA and a negative and a positive control group (NCG; PCG). The samples were stained with SYTO9 and propidium iodide and analyzed by CLSM. Bacterial viability was quantitatively analyzed by the proportions of dead and live bacteria in the biofilm remnants. Scores were standardized according to the total bacterial load (TBL)-1: ≤ 25%, 2: >25 ≤ 50%, 3: >50 ≤ 75%, 4: >75% and debris-1: absence of debris; 2: presence of debris. Statistical analysis was carried out through the Kruskal-Wallis and the Fischer exact tests (P = 0.05). RESULTS: No statistical differences were observed to CFU, debris and bacterial viability. CONCLUSION: None of the tested substances could completely eliminate Ef from the root canal space.
Assuntos
Biofilmes/efeitos dos fármacos , Enterococcus faecalis/efeitos dos fármacos , Enterococcus faecalis/fisiologia , Incisivo/microbiologia , Compostos Inorgânicos/uso terapêutico , Preparo de Canal Radicular , Animais , Bovinos , Contagem de Colônia Microbiana , Técnicas In Vitro , Viabilidade Microbiana/efeitos dos fármacos , Microscopia Confocal , Coloração e RotulagemRESUMO
AIM: Bacterial reduction in oval-shaped root canals by a single-instrument technique was compared ex vivo with a conventional nickel-titanium rotary technique. Data obtained from two quantification methods, quantitative real-time polymerase chain reaction (qPCR) and culture, were also compared. METHODOLOGY: Oval-shaped canals of extracted teeth contaminated with Enterococcus faecalis were instrumented using either a single Reciproc instrument or the BioRaCe instrument series. Bacteriological samples were taken before (S1) and after instrumentation (S2). Bacterial quantification was performed using qPCR and culture. RESULTS: Intragroup analysis showed that both protocols promoted a highly significant bacterial reduction (P < 0.001). Intergroup analysis (S2 samples) showed no significant differences between the two instrumentation systems (P > 0.05). As for the quantification methods, qPCR revealed significantly higher counts of E. faecalis in S1 than culture (P < 0.05), but no significant differences occurred for S2 (P > 0.05). CONCLUSION: The single-file technique was comparable with the conventional technique in oval-shaped canals provided the width of apical preparation, volume of irrigants and duration of irrigation are kept similar. No significant difference was observed for qPCR and culture in post-instrumentation samples, indicating that both methods can be reliably used for studies of antibacterial effectiveness.
Assuntos
Cavidade Pulpar/microbiologia , Enterococcus faecalis/isolamento & purificação , Preparo de Canal Radicular/instrumentação , Carga Bacteriana , Técnicas Bacteriológicas , Dente Pré-Molar/microbiologia , Biofilmes , Ligas Dentárias/química , Ácido Edético/uso terapêutico , Desenho de Equipamento , Humanos , Incisivo/microbiologia , Teste de Materiais , Microscopia Eletrônica de Varredura , Níquel/química , Reação em Cadeia da Polimerase em Tempo Real , Irrigantes do Canal Radicular/uso terapêutico , Preparo de Canal Radicular/métodos , Rotação , Camada de Esfregaço , Hipoclorito de Sódio/uso terapêutico , Titânio/químicaRESUMO
AIM: This was to characterise the microbial diversity in the complex dental plaque of children with severe early-childhood caries (S-ECC), using the denaturing gel gradient electrophoresis (DGGE) technique. METHODS: The DGGE technique was used as a diagnostic tool to analyse samples from the oral cavity of a patient with S-ECC. Dental plaque samples from a 3-year-old child with S-ECC were taken from the primary central maxillary incisor (biofilm on vestibular surface), primary maxillary molar (biofilm on vestibular surface), primary central maxillary incisor (dentine), primary maxillary molar (dentine) and saliva and then analysed by PCR-DGGE. RESULTS: Three bands occurred in all samples, moreover, 86% of similarity was observed in the pattern of bands between incisor and molar teeth biofilm samples, including four similar bands. CONCLUSION: DGGE is a valuable tool for differentiating the microbial composition of the oral plaque in S-ECC children.
Assuntos
Bactérias/classificação , Coinfecção/microbiologia , Cárie Dentária/microbiologia , Biofilmes , Pré-Escolar , Esmalte Dentário/microbiologia , Placa Dentária/microbiologia , Dentina/microbiologia , Eletroforese em Gel de Campo Pulsado , Humanos , Incisivo/microbiologia , Masculino , Dente Molar/microbiologia , Reação em Cadeia da Polimerase , Saliva/microbiologia , Dente Decíduo/microbiologiaRESUMO
INTRODUCTION: The aim of this study was to evaluate biofilm retention around orthodontic brackets related to the method of ligation by using optical coherence tomography (OCT) and microbiologic sampling. METHODS: Seventy-five plastic central incisors for dentures were divided into 3 groups and used with metal brackets with a 0.022-in slot with elastomeric ligature (n = 25), metal brackets with a 0.022-in slot with steel wire ligature (n = 25), and self-ligating brackets with a 0.022-in slot (n = 25). The samples were submersed in a suspension of Streptococcus mutans, genetically engineered to express green fluorescent protein, at 37°C for 72 hours to allow biofilm formation. The samples were then submitted to microbiologic analysis and OCT imaging. RESULTS: The microbiologic analysis and the OCT showed significant differences in biofilm formation depending on the ligating method. Brackets ligated with elastomeric rings held more S mutans biofilm, and steel wire ligation had less biofilm retention compared with the other brackets. CONCLUSIONS: This study provided validation that OCT can be used as a potential qualitative marker of total plaque bacteria that can be rapidly and reliably visualized around orthodontic brackets.