RESUMO
OBJECTIVE: This study aimed to evaluate the anti-caries effect of a fluoridated milk-based drink on a root caries model by assessing mineral loss and both biofilm microbial viability and acidogenicity under increasing concentrations of fluoride supplementation. DESIGN: Streptococcus mutans UA159 biofilms were grown on root dentin slabs for five days. The slabs were randomly assigned to following groups: milk-based drink (G1) and milk-based drink supplemented with 5-ppm NaF (G2), 10â¯ppm NaF (G3), and 20â¯ppm NaF (G4). A 10% sucrose and 0.9% NaCl solution were used as positive and negative-caries controls, respectively. Slabs/biofilms were exposed to the different treatments 3 times/day for 5â¯min. To estimate biofilm acidogenicity, the pH of the spent media was serially measured to calculate the area above the curve. Viable bacteria and dentin demineralization were assessed after the experimental phase. Results were compared using ANOVA followed by the Tukey test. RESULTS: G1 exhibited slightly lower acidogenicity than the positive caries control group (pâ¯<â¯0.05). G2, G3, and G4 induced lower acidogenicity than 10% sucrose and the non-supplemented milk-based drink. The lowest acidogenicity was found in G4 (pâ¯<â¯0.05). Fluoride-supplemented milk-based drinks (G2, G3, and G4) resulted in lower bacterial counts (pâ¯<â¯0.05) and induced lower demineralization (pâ¯<â¯0.05) than the positive caries control and non-supplemented milk-beverage (G1). There was a dose-dependent inhibition of demineralization with fluoride-supplemented milk-based drinks. CONCLUSIONS: Fluoride supplementation of a milk-based drink for older adults may reduce its cariogenicity in root dentin.
Assuntos
Cárie Dentária , Fluoretos/administração & dosagem , Alimentos Fortificados , Leite/química , Cárie Radicular , Desmineralização do Dente , Animais , Biofilmes , Cariostáticos/farmacologia , Cárie Dentária/prevenção & controle , Esmalte Dentário , Dentina , Técnicas In Vitro , Distribuição Aleatória , Cárie Radicular/prevenção & controle , Streptococcus mutans , Desmineralização do Dente/prevenção & controleRESUMO
The aim of this systematic review is to characterize and discuss key methodological aspects of in vitro biofilm models for caries-related research and to verify the reproducibility and dose-response of models considering the response to anti-caries and/or antimicrobial substances. Inclusion criteria were divided into Part I (PI): an in vitro biofilm model that produces a cariogenic biofilm and/or caries-like lesions and allows pH fluctuations; and Part II (PII): models showing an effect of anti-caries and/or antimicrobial substances. Within PI, 72.9% consisted of dynamic biofilm models, while 27.1% consisted of batch models. Within PII, 75.5% corresponded to dynamic models, whereas 24.5% corresponded to batch models. Respectively, 20.4 and 14.3% of the studies reported dose-response validations and reproducibility, and 32.7% were classified as having a high risk of bias. Several in vitro biofilm models are available for caries-related research; however, most models lack validation by dose-response and reproducibility experiments for each proposed protocol.
Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/crescimento & desenvolvimento , Cárie Dentária/microbiologia , Modelos Biológicos , Biofilmes/efeitos dos fármacos , Contagem de Colônia Microbiana , Meios de Cultura , Cárie Dentária/prevenção & controle , Relação Dose-Resposta a Droga , Humanos , Reprodutibilidade dos Testes , Saliva ArtificialRESUMO
The aim of this study was to evaluate the performance of a pen-type laser fluorescence (LF) device (LFpen: DIAGNOdent pen) to detect and monitor the progression of caries-like lesions on smooth surfaces. Fifty-two bovine enamel blocks were submitted to three different demineralisation cycles for caries-like lesion induction using Streptococcus mutans, Lactobacillus casei and Actinomyces naeslundii. At baseline and after each cycle, the enamel blocks were analysed under Knoop surface micro-hardness (SMH) and an LFpen. One enamel block after each cycle was randomly chosen for Raman spectroscopy analysis. Cross-sectional micro-hardness (CSMH) was performed at different depths (20, 40, 60, 80 and 100 µm) in 26 enamel blocks after the second cycle and 26 enamel blocks after the third cycle. Average values of SMH (± standard deviation (SD)) were 319.3 (± 21.5), 80.5 (± 31.9), 39.8 (± 12.7), and 29.77 (± 10.34) at baseline and after the first, second and third cycles, respectively. Statistical significant difference was found among all periods (p < 0.01). The LFpen values were 4.3 (± 1.5), 7.5 (± 9.4), 7.1 (± 7.1) and 5.10 (± 3.58) at baseline and after the first, second, and third cycles, respectively, among all periods (p < 0.05). The CSMH values after the second and third cycles at 20, 40, 60, 80 and 100 µm were 182.8 (± 69.8), 226.1 (± 79.6), 247.20 (± 69.36), 262.35 (± 66.36) and 268.45 (± 65.49), and for the third cycle were 193.7 (± 73.4), 239.5 (± 81.5), 262.64 (± 82.46), 287.10 (± 78.44) and 284.79 (± 72.63) (n = 24 and 23), respectively. No correlation was observed between the LFpen and SMH values (p > 0.05). One sample of each cycle was characterised through Raman spectroscopy analysis. It can be concluded that LF was effective in detecting the first demineralisation on enamel; however, the method did not show any effect in monitoring lesion progression after three cycles of in vitro demineralisation.
Assuntos
Cárie Dentária/diagnóstico , Cárie Dentária/patologia , Progressão da Doença , Fluorescência , Lasers , Análise de Variância , Animais , Bovinos , Esmalte Dentário/patologia , Dureza , Humanos , Análise Espectral Raman , Propriedades de Superfície , Desmineralização do DenteRESUMO
OBJECTIVE: The aim of this double-blind randomized clinical trial was to assess whether the presence of alcohol in chlorhexidine gluconate mouthwashes influences their antimicrobial potential against salivary bacteria in young adults. Additionally, the taste perception was assessed. MATERIALS AND METHODS: In a randomized crossover design, 20 participants (17 women and three men; aged 18-38 years old) rinsed with the 0.12% chlorhexidine gluconate with (CHX+) or without alcohol (CHX-) for 1 min. Sterile flavoured-mint physiological saline was used as control solution. All participants rinsed with the assigned products only once with a period of at least 7 days of washout in between. For antimicrobial potential assay, stimulated saliva samples were collected from participants and had their total viable bacteria determined before and after each rinse. For taste perception assay, a visual analogue scale (VAS) was used to evaluate the taste perception after each rinse. Friedman followed by Wilcoxon tests and Bonferroni correction were performed. A P-value <0.017 was considered as statistically significant. RESULTS: The median per cent reduction in groups CHX+ and CHX- was 16.07 and 12.87, respectively. No statistically significant difference was found between these groups (P = 0.09). Regarding the gustatory perception, the VAS median values in groups CHX+ and CHX- were 3.50 and 5.50. No statistically significant difference was found in this outcome (P = 0.052). CONCLUSIONS: The presence of the alcohol on the formulation of gluconate chlorhexidine mouthwashes does not seem to interfere with their antimicrobial potential and with their taste perception.
Assuntos
Anti-Infecciosos Locais/administração & dosagem , Clorexidina/análogos & derivados , Etanol/administração & dosagem , Antissépticos Bucais/administração & dosagem , Saliva/microbiologia , Percepção Gustatória , Adolescente , Adulto , Anti-Infecciosos Locais/farmacologia , Clorexidina/administração & dosagem , Clorexidina/farmacologia , Estudos Cross-Over , Método Duplo-Cego , Etanol/farmacologia , Feminino , Humanos , Masculino , Antissépticos Bucais/farmacologiaRESUMO
Some dynamic biofilm models for dental caries development are limited as they require multiple experiments and do not allow independent biofilm growth units, making them expensive and time-consuming. This study aimed to develop and test an in vitro dynamic microcosm biofilm model for caries lesion development and for dose-response to chlorhexidine. Microcosm biofilms were grown under two different protocols from saliva on bovine enamel discs for up to 21 days. The study outcomes were as follows: the percentage of enamel surface hardness change, integrated hardness loss, and the CFU counts from the biofilms formed. The measured outcomes, mineral loss and CFU counts showed dose-response effects as a result of the treatment with chlorhexidine. Overall, the findings suggest that biofilm growth for seven days with 0.06 ml min(-1) salivary flow under exposure to 5% sucrose (3 × daily, 0.25 ml min(-1), 6 min) was suitable as a pre-clinical model for enamel demineralization and antimicrobial studies.
Assuntos
Biofilmes , Clorexidina/farmacologia , Cárie Dentária , Desmineralização do Dente , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Bovinos , Contagem de Colônia Microbiana/métodos , Cárie Dentária/diagnóstico , Cárie Dentária/etiologia , Cárie Dentária/microbiologia , Cárie Dentária/prevenção & controle , Esmalte Dentário/efeitos dos fármacos , Esmalte Dentário/patologia , Relação Dose-Resposta a Droga , Testes de Dureza/métodos , Humanos , Modelos Biológicos , Antissépticos Bucais/farmacologia , Saliva/microbiologia , Desmineralização do Dente/diagnóstico , Desmineralização do Dente/prevenção & controleRESUMO
The aim of this systematic literature review was to investigate whether the incorporation of antimicrobial agents into dental restorative materials truly exerts an antimicrobial effect against common cariogenic bacteria (primary outcome), and whether the inclusion of antimicrobial agents is able to prevent caries around restorations (secondary outcome). MEDLINE, via PubMed, was searched for papers published between 1980 and 30 November 2014. A total of 1126 articles were retrieved. After inclusion/exclusion assessment, 147 full text articles were read and included in the review, comprising 130 in vitro, 1 in situ, and 4 in vivo studies, as well as 12 literature reviews. In about 78% of in vitro studies, and in all identified in situ and in vivo studies, a positive antimicrobial effect had been found. However, the anticaries effect had not been tested in any of the selected studies. It was concluded that there is indeed evidence that restorative dental materials containing antimicrobial agents exert an antimicrobial effect, both in laboratory and in clinical studies. However, no evidence has been found regarding the role of these agents in preventing or controlling dental caries, or in preventing caries around restorations.
RESUMO
The aim of this study was to investigate the temporal relationship between changes in biofilm composition and enamel demineralization following exposure to sucrose. A crossover blind study was conducted in situ in three phases, during which 12 volunteers, divided into three groups, subjected enamel slabs 8 times/day to water (negative control), 10% glucose + 10% fructose (active control) or 20% sucrose solution. Biofilms accumulated for 3, 7 and 14 days were collected and analyzed biochemically and microbiologically, and mineral loss from enamel (deltaZ) was evaluated. Significantly higher deltaZ was found in the sucrose group after 7 days. However, on the 3rd day, lactobacilli, insoluble extracellular polysaccharide (EPS) and intracellular polysaccharide were significantly higher, and the calcium, inorganic phosphorus and fluoride concentrations in the biofilm were significantly lower in the sucrose group than in the negative controls. The only significant difference compared to glucose + fructose treatment was a higher insoluble EPS concentration. The data suggest that, although sucrose induces significant enamel demineralization only after 7 days of biofilm accumulation, changes in the biofilm composition are observed earlier.