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Willmott T, Serrage HJ, Cottrell EC, Humphreys GJ, Myers J, Campbell PM, McBain AJ. Investigating the association between nitrate dosing and nitrite generation by the human oral microbiota in continuous culture. Appl Environ Microbiol 2024; 90:e0203523. [PMID: 38440981 PMCID: PMC11022587 DOI: 10.1128/aem.02035-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Accepted: 02/13/2024] [Indexed: 03/06/2024] Open
Abstract
The generation of nitrite by the oral microbiota is believed to contribute to healthy cardiovascular function, with oral nitrate reduction to nitrite associated with systemic blood pressure regulation. There is the potential to manipulate the composition or activities of the oral microbiota to a higher nitrate-reducing state through nitrate supplementation. The current study examined microbial community composition and enzymatic responses to nitrate supplementation in sessile oral microbiota grown in continuous culture. Nitrate reductase (NaR) activity and nitrite concentrations were not significantly different to tongue-derived inocula in model biofilms. These were generally dominated by Streptococcus spp., initially, and a single nitrate supplementation resulted in the increased relative abundance of the nitrate-reducing genera Veillonella, Neisseria, and Proteus spp. Nitrite concentrations increased concomitantly and continued to increase throughout oral microbiota development. Continuous nitrate supplementation, over a 7-day period, was similarly associated with an elevated abundance of nitrate-reducing taxa and increased nitrite concentration in the perfusate. In experiments in which the models were established in continuous low or high nitrate environments, there was an initial elevation in nitrate reductase, and nitrite concentrations reached a relatively constant concentration over time similar to the acute nitrate challenge with a similar expansion of Veillonella and Neisseria. In summary, we have investigated nitrate metabolism in continuous culture oral biofilms, showing that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of putatively NaR-producing taxa.IMPORTANCEClinical evidence suggests that blood pressure regulation can be promoted by nitrite generated through the reduction of supplemental dietary nitrate by the oral microbiota. We have utilized oral microbiota models to investigate the mechanisms responsible, demonstrating that nitrate addition increases nitrate reductase activity and nitrite concentrations in oral microbiota with the expansion of nitrate-reducing taxa.
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Affiliation(s)
- Thomas Willmott
- Maternal and Fetal Health Research Centre, Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Hannah J. Serrage
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Elizabeth C. Cottrell
- Maternal and Fetal Health Research Centre, Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Gavin J. Humphreys
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Jenny Myers
- Maternal and Fetal Health Research Centre, Division of Developmental Biology & Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Paul M. Campbell
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | - Andrew J. McBain
- Division of Pharmacy and Optometry, School of Health Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
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Khosravi Y, Palmer S, Daep CA, Sambanthamoorthy K, Kumar P, Dusane D, Stoodley P. A commercial SnF 2 toothpaste formulation reduces simulated human plaque biofilm in a dynamic typodont model. J Appl Microbiol 2022; 133:1341-1352. [PMID: 35603698 PMCID: PMC9542754 DOI: 10.1111/jam.15634] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 04/29/2022] [Accepted: 05/19/2022] [Indexed: 11/28/2022]
Abstract
AIMS We present a dynamic typodont biofilm model (DTBM) incorporating 1) human dentition anatomy, 2) fluid flow over intermittently fluid bathed tooth surfaces and 3) an oxic headspace to allow aerobic and anaerobic niches to develop naturally, as a screening tool to assess the effect of stannous fluoride (SnF2 ) toothpaste against a simulated human plaque biofilm (SPB). METHODS AND RESULTS First, hydroxyapatite (HA) coupons were inoculated with human saliva/plaque and cultured at 37o C under air. Selected species representative of common commensal and anaerobic pathogens were quantified for relative abundance changes over 4d by PCR densitometry to confirm the culture conditions allowed the proliferation of these species. A continuous culture DTBM reactor on a rocker table was inoculated with saliva/plaque and incubated at 37°C for 24h. Tooth shear stress was estimated by particle tracking. A SnF2 toothpaste solution, or a sham rise was administered twice daily for 3d to mimic routine oral hygiene. SPB biomass was assessed by total bacterial DNA and methylene blue (MB) staining. Early colonizer aerobes and late colonizer anaerobes species were detected in the HA and DTBM, and the trends in changing abundance were consistent with those seen clinically. CONCLUSIONS Treatment with the SnF2 solution showed significant reductions of 53.05% and 54.4% in the SPB by MB staining and DNA, respectively. SIGNIFICANCE AND IMPACT OF STUDY The model has potential for assessing dentition anatomy and fluid flow on the efficacy of antimicrobial efficacy against localized SPB and may be amenable to the plaque index clinical evaluation.
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Affiliation(s)
- Yalda Khosravi
- Department of Microbial Infection and Immunity, Ohio State University Columbus, OH, USA
| | - Sara Palmer
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | | | | | - Purnima Kumar
- College of Dentistry, The Ohio State University, Columbus, OH, USA
| | - Devendra Dusane
- Department of Microbial Infection and Immunity, Ohio State University Columbus, OH, USA
| | - Paul Stoodley
- Department of Microbial Infection and Immunity, Ohio State University Columbus, OH, USA.,Dept. Orthopaedics, Ohio State University, Columbus, OH, USA.,National Centre for Advanced Tribology (nCATS) and National Biofilm Innovation Centre (NBIC), Mechanical Engineering, University of Southampton, UK
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Luo TL, Vanek ME, Gonzalez-Cabezas C, Marrs CF, Foxman B, Rickard AH. In vitro model systems for exploring oral biofilms: From single-species populations to complex multi-species communities. J Appl Microbiol 2022; 132:855-871. [PMID: 34216534 PMCID: PMC10505481 DOI: 10.1111/jam.15200] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 06/05/2021] [Accepted: 06/29/2021] [Indexed: 12/13/2022]
Abstract
Numerous in vitro biofilm model systems are available to study oral biofilms. Over the past several decades, increased understanding of oral biology and advances in technology have facilitated more accurate simulation of intraoral conditions and have allowed for the increased generalizability of in vitro oral biofilm studies. The integration of contemporary systems with confocal microscopy and 16S rRNA community profiling has enhanced the capabilities of in vitro biofilm model systems to quantify biofilm architecture and analyse microbial community composition. In this review, we describe several model systems relevant to modern in vitro oral biofilm studies: the constant depth film fermenter, Sorbarod perfusion system, drip-flow reactor, modified Robbins device, flowcells and microfluidic systems. We highlight how combining these systems with confocal microscopy and community composition analysis tools aids exploration of oral biofilm development under different conditions and in response to antimicrobial/anti-biofilm agents. The review closes with a discussion of future directions for the field of in vitro oral biofilm imaging and analysis.
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Affiliation(s)
- Ting L. Luo
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Michael E. Vanek
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Carlos Gonzalez-Cabezas
- Department of Cariology, Restorative Sciences and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA
| | - Carl F. Marrs
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Betsy Foxman
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
| | - Alexander H. Rickard
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI, USA
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Dutra H, Barbosa I, Câmara JV, Pereira G. Influence of brushing with natural dentifrices on color change: In vitro study. J Clin Exp Dent 2021; 13:e809-e816. [PMID: 34512921 PMCID: PMC8412801 DOI: 10.4317/jced.58066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2020] [Accepted: 03/15/2021] [Indexed: 11/12/2022] Open
Abstract
Background To evaluate in vitro the influence of daily brushing with the use of natural toothpastes on the color change of enamel in bovine teeth.
Material and Methods Four dentifrices were used, one conventional Colgate Total 12 - Clean Mint (G1), and three natural, Contented Toothpaste with Organic and Natural Ingredients (G2); Dental Toothpaste (G3) and Aliv-Gaia Toothpaste (G4). Eighty bovine teeth were distributed in four experimental groups with 20 teeth each (n = 20). The buccal enamel surface of the teeth was subjected to brushing, with the related dentifrices of each group, for 2.13 seconds three times a day, with an electric brush Oral B 5000 Professional Care. Before and after brushing, color measurement tests with a spectrophotometer were performed. The color variation was calculated using the formula ΔE = [(ΔL *) 2+ (Δa *) 2+ (Δb *)2] 1/2. The results obtained were tabulated and submitted to the Kruskal Wallis non-parametric test.
Results The color change (ΔE) observed was 7.551 and p-value equal to 0.056, determining that there was no statistically significant difference between the groups. However, qualitative tests showed the clearing of all experimental groups, G3 with the greatest change, followed by G2, G1 and G4.
Conclusions The evaluated dentifrices were not able to promote color change. Key words:Dental enamel, plant extracts, saliva, artificial, dentifrices.
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Affiliation(s)
- Helena Dutra
- MSc, Department of Dental Clinic, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
| | - Isabel Barbosa
- PhD, Department of Restorative Detistry, Piracicaba School of Dentistry, Campinas State University, Piracicaba, São Paulo, Brasil
| | - João-Victor Câmara
- Master student, Department of Biological Sciences, Bauru School of Dentistry, University of São Paulo, Bauru, São Paulo, Brazil
| | - Gisele Pereira
- Adjunct Professor, Department of Dental Clinic, School of Dentistry, Federal University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil
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Gomes IB, Meireles A, Gonçalves AL, Goeres DM, Sjollema J, Simões LC, Simões M. Standardized reactors for the study of medical biofilms: a review of the principles and latest modifications. Crit Rev Biotechnol 2017; 38:657-670. [DOI: 10.1080/07388551.2017.1380601] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Inês B. Gomes
- LEPABE – Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| | - Ana Meireles
- LEPABE – Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| | - Ana L. Gonçalves
- LEPABE – Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| | - Darla M. Goeres
- Center for Biofilm Engineering, Montana State University, Bozeman, MT, USA
| | - Jelmer Sjollema
- University of Groningen, University Medical Center Groningen, Department of Biomedical Engineering, Groningen, The Netherlands
| | - Lúcia C. Simões
- LEPABE – Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
| | - Manuel Simões
- LEPABE – Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia, Faculdade de Engenharia da Universidade do Porto, Porto, Portugal
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Dental Biofilm and Laboratory Microbial Culture Models for Cariology Research. Dent J (Basel) 2017; 5:dj5020021. [PMID: 29563427 PMCID: PMC5806974 DOI: 10.3390/dj5020021] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 05/24/2017] [Accepted: 06/15/2017] [Indexed: 01/03/2023] Open
Abstract
Dental caries form through a complex interaction over time among dental plaque, fermentable carbohydrate, and host factors (including teeth and saliva). As a key factor, dental plaque or biofilm substantially influence the characteristic of the carious lesions. Laboratory microbial culture models are often used because they provide a controllable and constant environment for cariology research. Moreover, they do not have ethical problems associated with clinical studies. The design of the microbial culture model varies from simple to sophisticated according to the purpose of the investigation. Each model is a compromise between the reality of the oral cavity and the simplification of the model. Researchers, however, can still obtain meaningful and useful results from the models they select. Laboratory microbial culture models can be categorized into a closed system and an open system. Models in the closed system have a finite supply of nutrients, and are also simple and cost-effective. Models in the open system enabled the supply of a fresh culture medium and the removal of metabolites and spent culture liquid simultaneously. They provide better regulation of the biofilm growth rate than the models in the closed system. This review paper gives an overview of the dental plaque biofilm and laboratory microbial culture models used for cariology research.
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Fernández CE, Fontana M, Samarian D, Cury JA, Rickard AH, González-Cabezas C. Effect of Fluoride-Containing Toothpastes on Enamel Demineralization and Streptococcus mutans Biofilm Architecture. Caries Res 2016; 50:151-8. [PMID: 27073873 DOI: 10.1159/000444888] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 02/22/2016] [Indexed: 11/19/2022] Open
Abstract
This study aimed to explore the effect of fluoridated toothpastes on biofilm architecture and enamel demineralization in an in vitro biofilm model. Streptococcus mutans was grown on enamel and treated with slurries of commercial toothpastes, containing SnF2 or NaF. Water and chlorhexidine were used as negative and positive controls, respectively. The developed biofilms were imaged and enamel demineralization was measured. SnF2 and NaF toothpaste treatments significantly reduced enamel demineralization, but SnF2 toothpaste was more effective. Only SnF2 toothpaste and chlorhexidine treatments caused reductions on biofilm mass and thickness. In conclusion, this biofilm model was able to differentiate the effects of the SnF2 and NaF toothpastes on biofilm architecture and enamel demineralization.
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Affiliation(s)
- Constanza E Fernández
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, Mich., USA
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Brambilla E, Ionescu A, Cazzaniga G, Ottobelli M. Influence of Light-curing Parameters on Biofilm Development and Flexural Strength of a Silorane-based Composite. Oper Dent 2016; 41:219-27. [DOI: 10.2341/14-279-l] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARYObjectives: The aim of this study was to evaluate the differences in biological and mechanical performances of a silorane-based and a methacrylate-based composite. Another aim was to assess the influence of light-curing time and light-curing intensity on in vitro biofilm formation and flexural strength of the two tested composites.Methods: Experiment 1: 432 specimens obtained from a silorane-based composite and from a standard methacrylate-based composite were divided into six groups and light-cured for 10, 20, 30, 40, 60, or 80 seconds, using one of two light-curing intensities, 400 mW/cm2 or 800 mW/cm2. At 24 hours, a monospecific Streptococcus mutans biofilm adherent to the surfaces of the samples was obtained. Then, a colorimetric technique (MTT assay) was used to evaluate the adherent viable biomass. Two samples per group were observed using confocal laser scanning microscopy. Analysis of variance (ANOVA) and Tukey tests were used to analyze the results (p<0.05). Experiment 2: 192 bar-shaped specimens were obtained and light-cured as in the previous experiment. A three-point bend test using a universal testing machine was performed to obtain flexural strength values. ANOVA and Tukey tests were used to analyze the results (p<0.05).Results: In experiment 1, a highly significant difference (p<0.0001) in biofilm development was shown between silorane-based and methacrylate-based composites. In fact, the silorane-based composite exhibited better biological performance. Significant differences were also found between the two light-curing intensities (p<0.018) and for curing times (p<0.0001): silorane-based composite light-cured for 80 seconds at 800 mW/cm2 light-curing intensity showed the lowest biofilm development. In experiment 2, a significant difference in flexural strength (p<0.0318) was only found between the different composites. Nevertheless, both resin composites showed flexural strength values in accordance with International Organization for Standardization guidelines even after 10 seconds of light-curing time.Conclusions: Silorane-based composite was less prone to biofilm development compared with a methacrylate-based composite. Acceptable flexural strength values for both composites were obtained after 10 seconds of light-curing time.
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Affiliation(s)
- E Brambilla
- Eugenio Brambilla, DDS, IRCCS Galeazzi Institute, University of Milan, Department of Biomedical, Surgical and Dental Sciences, Milan, Italy
| | - A Ionescu
- Andrei Ionescu, DDS, PhD, IRCCS Galeazzi Institute, University of Milan, Department of Biomedical, Surgical and Dental Sciences, Milan, Italy
| | - G Cazzaniga
- Gloria Cazzaniga, DDS, IRCCS Galeazzi Institute, University of Milan, Department of Biomedical, Surgical and Dental Sciences, Milan, Italy
| | - M Ottobelli
- Eugenio Brambilla, DDS, IRCCS Galeazzi Institute, University of Milan, Department of Biomedical, Surgical and Dental Sciences, Milan, Italy
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Fernández CE, Tenuta LMA, Cury JA. Validation of a Cariogenic Biofilm Model to Evaluate the Effect of Fluoride on Enamel and Root Dentine Demineralization. PLoS One 2016; 11:e0146478. [PMID: 26731743 PMCID: PMC4712139 DOI: 10.1371/journal.pone.0146478] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 12/17/2015] [Indexed: 01/01/2023] Open
Abstract
Due to gingival recession both enamel and root dentine are at risk of developing caries. Both tissues are exposed to a similar environment, however there is not a validated model to evaluate the effect of fluoride on these dental substrates simultaneously. Hence, this study aimed to validate a caries model to evaluate the effect of fluoride to prevent demineralization on enamel and root-dentine. Streptococcus mutans UA159 biofilms were formed on saliva-coated bovine enamel and root dentine slabs (n = 12 per group) mounted in the same well of culture plates. The biofilms were exposed 8×/day to 10% sucrose and treated 2×/day with fluoridated solutions containing 0, 150, 450, or 1,350 ppm F; thus, simulating the use of low to high fluoride concentration toothpastes. The pH values of the culture medium was monitored 2×/day as a biofilm acidogenicity indicator. After 96 h, biofilms were collected for fluoride concentration analysis. The percentage of surface hardness loss (%SHL) was calculated for slabs. The fluoride uptake by the enamel and dentine was also determined. The model showed a dose-response because the biofilm and fluoride uptake increased and %SHL decreased at increasing fluoride concentrations (p < 0.05). Fluoride in the biofilm formed on dentine and fluoride uptake by dentine were higher than those for enamel. With the same fluoride concentration treatment, the percentage of reduction of demineralization was lower for dentine than for enamel. In conclusion, the model was validated in terms of a dose-response effect of fluoride on enamel and root dentine. Furthermore, the findings support the clinical data, suggesting that higher fluoride concentrations are necessary to control caries of root dentine than of enamel.
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Affiliation(s)
- Constanza E. Fernández
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil
| | - Livia M. A. Tenuta
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil
| | - Jaime A. Cury
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, São Paulo, Brazil
- * E-mail:
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Latimer J, Munday JL, Buzza KM, Forbes S, Sreenivasan PK, McBain AJ. Antibacterial and anti-biofilm activity of mouthrinses containing cetylpyridinium chloride and sodium fluoride. BMC Microbiol 2015; 15:169. [PMID: 26293609 PMCID: PMC4546200 DOI: 10.1186/s12866-015-0501-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/05/2015] [Indexed: 11/22/2022] Open
Abstract
Background Cetylpyridinium chloride (CPC) and sodium fluoride augment oral hygiene by inactivating bacteria and inhibiting enamel demineralisation, respectively. However, there are few reports in the literature documenting the antibacterial efficacy of their combined use in mouthrinses. We have used six experimental systems to compare the antibacterial effects of mouthrinses containing 0.075 % CPC (test rinse, TR) or 0.075 % CPC with sodium fluoride (test fluoride rinse, TFR). Results Effects against planktonic bacteria were determined using viable counting (for Streptococcus mutans and salivary bacteria), a redox dye (for Actinomyces viscosus and salivary bacteria) and viable counting (for ex vivo oral rinses). Effects against saliva-derived biofilms were quantified using confocal microscopy and differential viable counting. Inhibition of biofilm formation was evaluated by pre-treating hydroxyapatite coupons with mouthrinses prior to inoculation. Otherwise-identical controls without CPC (control rinse and control fluoride rinse, CR and CFR, respectively), were included throughout. Compared to the controls, TFR and TR demonstrated significant antimicrobial effects in the redox assays, by viable counts (>3 log reductions) and in oral rinse samples (>1.25 log reductions, p < 0.05). TFR and TR also significantly reduced the viability of oral biofilms. Pre-treatment of hydroxyapatite with TFR and TR significantly inhibited biofilm formation (>3 log difference, p < 0.05). Overall, there were no consistent differences in the activities of TR and TFR. Conclusions Sodium fluoride did not influence the antibacterial and anti-biofilm potency of CPC-containing formulations, supporting the combined use of CPC and sodium fluoride in mouthrinses to control oral bacteria and protect tooth enamel.
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Affiliation(s)
- Joe Latimer
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - Jodie L Munday
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - Kara M Buzza
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | - Sarah Forbes
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
| | | | - Andrew J McBain
- Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
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Khvostenko D, Salehi S, Naleway SE, Hilton TJ, Ferracane JL, Mitchell JC, Kruzic JJ. Cyclic mechanical loading promotes bacterial penetration along composite restoration marginal gaps. Dent Mater 2015; 31:702-10. [PMID: 25900624 DOI: 10.1016/j.dental.2015.03.011] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2014] [Revised: 01/26/2015] [Accepted: 03/24/2015] [Indexed: 10/23/2022]
Abstract
OBJECTIVES Secondary caries is the most common reason for composite restoration replacement and usually forms between dentin and the filling. The objective of this study was to investigate the combined effect of cyclic loading and bacterial exposure on bacterial penetration into gaps at the interface between dentin and resin composite restorative material using a novel bioreactor system and test specimen design. METHODS Human molars were machined into 3mm thick disks with 2mm deep × 5 mm diameter cavity preparations into which composite restorations were placed. A ∼ 15-30 μm (small) or ∼ 300 μm wide (large) marginal gap was introduced along half of the interface between the dentin and restoration. Streptococcus mutans UA 159 biofilms were grown on each sample prior to testing each in a bioreactor both with and without cyclic loading. Both groups of samples were tested for 2 weeks and post-test biofilm viability was confirmed with a live-dead assay. Samples were fixed, mounted and cross-sectioned to reveal the gaps and observe the depth of bacterial penetration. RESULTS It was shown that for large gap samples the bacteria easily penetrated to the full depth of the gap independent of loading or non-loading conditions. The results for all cyclically loaded small gap samples show a consistently deep bacterial penetration down 100% of the gap while the average penetration depth was only 67% for the non-loaded samples with only two of six samples reaching 100%. SIGNIFICANCE A new bioreactor was developed that allows combining cyclic mechanical loading and bacterial exposure of restored teeth for bacterial biofilm and demineralization studies. Cyclic loading was shown to aid bacterial penetration into narrow marginal gaps, which could ultimately promote secondary caries formation.
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Affiliation(s)
- D Khvostenko
- Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR, USA
| | - S Salehi
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - S E Naleway
- Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR, USA
| | - T J Hilton
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - J L Ferracane
- Department of Restorative Dentistry, School of Dentistry, Oregon Health & Science University, Portland, OR, USA
| | - J C Mitchell
- College of Dental Medicine, Midwestern University, Glendale, AZ, USA
| | - J J Kruzic
- Materials Science, School of Mechanical, Industrial, and Manufacturing Engineering, Oregon State University, Corvallis, OR, USA.
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Samarian DS, Jakubovics NS, Luo TL, Rickard AH. Use of a high-throughput in vitro microfluidic system to develop oral multi-species biofilms. J Vis Exp 2014:52467. [PMID: 25490193 PMCID: PMC4354480 DOI: 10.3791/52467] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
There are few high-throughput in vitro systems which facilitate the development of multi-species biofilms that contain numerous species commonly detected within in vivo oral biofilms. Furthermore, a system that uses natural human saliva as the nutrient source, instead of artificial media, is particularly desirable in order to support the expression of cellular and biofilm-specific properties that mimic the in vivo communities. We describe a method for the development of multi-species oral biofilms that are comparable, with respect to species composition, to supragingival dental plaque, under conditions similar to the human oral cavity. Specifically, this methods article will describe how a commercially available microfluidic system can be adapted to facilitate the development of multi-species oral biofilms derived from and grown within pooled saliva. Furthermore, a description of how the system can be used in conjunction with a confocal laser scanning microscope to generate 3-D biofilm reconstructions for architectural and viability analyses will be presented. Given the broad diversity of microorganisms that grow within biofilms in the microfluidic system (including Streptococcus, Neisseria, Veillonella, Gemella, and Porphyromonas), a protocol will also be presented describing how to harvest the biofilm cells for further subculture or DNA extraction and analysis. The limits of both the microfluidic biofilm system and the current state-of-the-art data analyses will be addressed. Ultimately, it is envisioned that this article will provide a baseline technique that will improve the study of oral biofilms and aid in the development of additional technologies that can be integrated with the microfluidic platform.
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Affiliation(s)
- Derek S Samarian
- Department of Epidemiology, School of Public Health, The University of Michigan
| | | | - Ting L Luo
- Department of Epidemiology, School of Public Health, The University of Michigan
| | - Alexander H Rickard
- Department of Epidemiology, School of Public Health, The University of Michigan;
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Bacteriological effects of dentifrices with and without active ingredients of natural origin. Appl Environ Microbiol 2014; 80:6490-8. [PMID: 25107974 DOI: 10.1128/aem.02315-14] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Compounds of natural origin are increasingly used as adjuncts to oral hygiene. We have adopted four distinct approaches to assess the antibacterial activity of dentifrices containing natural active ingredients against oral bacteria in several test systems. Corsodyl Daily (CD), Kingfisher Mint (KM), and Parodontax fluoride (PF) were compared to a dentifrice containing fluoride (Colgate Cavity Protection [CCP]) and one containing triclosan (Colgate Total [CT]). The growth inhibitory and bactericidal potency of the formulations were determined for 10 isolated oral bacteria. Effects of single exposures of simulated supragingival plaques were then determined by epifluorescence and confocal microscopy, while the effects of repeated exposures were quantified by viable counting. Additionally, dense plaques, maintained in continuous culture, were repeatedly dosed, and the outcome was assessed by viable counting and eubacterial DNA profiling. The test dentifrices exhibited variable specificity and potency against oral bacteria in axenic culture. Of the herbal formulations, KM caused the largest viability reductions in simulated supragingival plaques, with CT causing the greatest reductions overall. Following single exposures, CD caused moderate reductions, while PF had no effect. After multiple dosing, all formulations significantly reduced numbers of total, facultative, and Gram-negative anaerobes, but only KM and CT caused greater reductions than the fluoride control. KM also reduced counts of streptococci (rank order of effectiveness: CT > KM > CCP > PF > CD). Marked changes in eubacterial DNA profiles were not detected for any herbal formulation in dense plaques, although KM markedly reduced viable counts of streptococci, in agreement with supragingival data. While both nonherbal comparators displayed antibacterial activity, the triclosan-containing formulation caused greater viability reductions than the herbal and nonherbal formulations.
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Madhwani T, McBain AJ. Compositional modification of nascent in vitro dental plaques by human host-defence peptides. ACTA ACUST UNITED AC 2012; 64:374-81. [PMID: 22171654 DOI: 10.1111/j.1574-695x.2011.00922.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2011] [Revised: 12/04/2011] [Accepted: 12/07/2011] [Indexed: 12/19/2022]
Abstract
Salivary host-defence peptides include defensins, histatins and cathelicidin. We have investigated the effects of these peptides on the microbial composition of dental plaques. Salivary consortia, established within hydroxyapatite disc models, were exposed during development to physiological levels of human neutrophil proteins (HNP) 1 and 2; human β defensins (hβD) 1, 2 and 3; histatins (His) 5 and 8; and cathelicidin (LL37). Effects on aggregation and microbial composition were determined using fluorescence microscopy; and differential culture with PCR-DGGE, respectively. LIVE/DEAD microscopic analysis indicated that HDPs decreased total bacterial viability, whilst β defensins, paired HNPs, His 5, His 8 and the HDPs combined inhibited bacterial aggregation. According to differential culture, all test HDPs (except His 5) significantly decreased the abundance of Gram-negative anaerobes and lactobacilli (except HNP 2, hβD 1, paired HNPs and His 5). Combined HNPs and paired hβD 1 and 3 inhibited streptococci, whereas HNP 1, hβD 1, hβD 3, His 5 and LL37 increased streptococcal numbers. According to cluster analyses of DGGE profiles, HDP-exposed plaques were compositionally distinct from undosed controls. Thus, whilst HDPs reportedly exhibit variable potency against oral bacteria in endpoint susceptibly tests, exposure of nascent plaques can markedly influence bacterial viability, composition and microbial aggregation.
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Affiliation(s)
- Tejal Madhwani
- School of Pharmacy and Pharmaceutical Sciences, The University of Manchester, Manchester, UK
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