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Banerjee A, Kang CY, An M, Koff BB, Sunder S, Kumar A, Tenuta LMA, Stockbridge RB. Fluoride export is required for the competitive fitness of pathogenic microorganisms in dental biofilm models. mBio 2024:e0018424. [PMID: 38624207 DOI: 10.1128/mbio.00184-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Accepted: 03/20/2024] [Indexed: 04/17/2024] Open
Abstract
Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas oral commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with the genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of oral commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time. Biochemical purification of the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms and that S. mutans is especially susceptible to fluoride toxicity. IMPORTANCE Dental caries is a globally prevalent condition that occurs when pathogenic species, including Streptococcus mutans and Candida albicans, outcompete beneficial species, such as Streptococcus gordonii, in the dental biofilm. Fluoride is routinely used in oral hygiene to prevent dental caries. Fluoride also has antimicrobial properties, although most microbes possess fluoride exporters to resist its toxicity. This work shows that sensitization of cariogenic species S. mutans and C. albicans to fluoride by genetic knockout of fluoride exporters alters the microbial composition and pathogenic properties of dental biofilms. These results suggest that the development of drugs that inhibit fluoride exporters could potentiate the anticaries effect of fluoride in over-the-counter products like toothpaste and mouth rinses. This is a novel strategy to treat dental caries.
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Affiliation(s)
- Aditya Banerjee
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Chia-Yu Kang
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
| | - Minjun An
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - B Ben Koff
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Sham Sunder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Livia M A Tenuta
- School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
- Program in Biophysics, University of Michigan, Ann Arbor, Michigan, USA
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Abstract
The interactions between communities of microorganisms inhabiting the dental biofilm is a major determinant of oral health. These biofilms are periodically exposed to high concentrations of fluoride, which is present in almost all oral healthcare products. The microbes resist fluoride through the action of membrane export proteins. This chapter describes the culture, growth and harvest conditions of model three-species dental biofilm comprised of cariogenic pathogens Streptococcus mutans and Candida albicans and the commensal bacterium Streptococcus gordonii. In order to examine the role of fluoride export by S. mutans in model biofilms, procedures for generating a strain of S. mutans with a genetic knockout of the fluoride exporter are described. We present a case study examining the effects of this mutant strain on the biofilm mass, acid production and mineral dissolution under exposure to low levels of fluoride. These general approaches can be applied to study the effects of any gene of interest in physiologically realistic multispecies oral biofilms.
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Affiliation(s)
- Aditya Banerjee
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, United States
| | - Livia M A Tenuta
- School of Dentistry, University of Michigan, Ann Arbor, MI, United States.
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Wing JTF, Hayashi MAL, Redissi AF, Vickerman MM, Tenuta LMA, Fenno JC, Rickard AH. Time-lapse confocal microscopy to study in vitro Streptococcus mutans surface colonization. Lett Appl Microbiol 2024; 77:ovae012. [PMID: 38331426 DOI: 10.1093/lambio/ovae012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Revised: 01/26/2024] [Accepted: 02/06/2024] [Indexed: 02/10/2024]
Abstract
The cariogenicity of Streptococcus mutans relates to its ability to form biofilms on dental surfaces. The aim of this work was to develop a flowcell system compatible with time-lapse confocal microscopy to compare the adhesion and accumulation of S. mutans cells on surfaces in unsupplemented media against media containing sucrose or sucralose (a non-metabolized sweetener) over a short period of time. Fluorescent S. mutans 3209/pVMCherry was suspended in unsupplemented media or media supplemented with 1% sucrose or 1% sucralose and passed through a 3D-printed flowcell system. Flowcells were imaged over 60 minutes using a confocal microscope. Image analysis was performed, including a newly developed object-movement-based method to measure biomass adhesion. Streptococcus mutans 3209/pVMCherry grown in 1% sucrose-supplemented media formed small, dense, relatively immobile clumps in the flowcell system measured by biovolume, surface area, and median object centroid movement. Sucralose-supplemented and un-supplemented media yielded large, loose, mobile aggregates. Architectural metrics and per-object movement were significantly different (P < 0.05) when comparing sucrose-supplemented media to either unsupplemented or sucralose-supplemented media. These results demonstrate the utility of a flowcell system compatible with time-lapse confocal microscopy and image analysis when studying initial biofilm formation and adhesion under different nutritional conditions.
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Affiliation(s)
- Jason T F Wing
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, United States
| | - Michael A L Hayashi
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, United States
| | - Aneesa F Redissi
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, United States
| | - M Margaret Vickerman
- Department of Oral Biology, School of Dental Medicine, University at Buffalo, Buffalo, NY 14214, United States
| | - Livia M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - J Christopher Fenno
- Department of Biologic and Materials Sciences & Prosthodontics, School of Dentistry, University of Michigan, Ann Arbor, MI 48109, United States
| | - Alexander H Rickard
- Department of Epidemiology, University of Michigan School of Public Health, Ann Arbor, MI 48109, United States
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Banerjee A, Kang CY, An M, Koff BB, Sunder S, Kumar A, Tenuta LMA, Stockbridge RB. Fluoride export is required for competitive fitness of pathogenic microorganisms in dental biofilm models. bioRxiv 2024:2024.01.18.576223. [PMID: 38293214 PMCID: PMC10827179 DOI: 10.1101/2024.01.18.576223] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
Microorganisms resist fluoride toxicity using fluoride export proteins from one of several different molecular families. Cariogenic species Streptococcus mutans and Candida albicans extrude intracellular fluoride using a CLCF F-/H+ antiporter and FEX fluoride channel, respectively, whereas commensal eubacteria, such as Streptococcus gordonii, export fluoride using a Fluc fluoride channel. In this work, we examine how genetic knockout of fluoride export impacts pathogen fitness in single-species and three-species dental biofilm models. For biofilms generated using S. mutans with genetic knockout of the CLCF transporter, exposure to low fluoride concentrations decreased S. mutans counts, synergistically reduced the populations of C. albicans, increased the relative proportion of commensal S. gordonii, and reduced properties associated with biofilm pathogenicity, including acid production and hydroxyapatite dissolution. Biofilms prepared with C. albicans with genetic knockout of the FEX channel also exhibited reduced fitness in the presence of fluoride, but to a lesser degree. Imaging studies indicate that S. mutans is highly sensitive to fluoride, with the knockout strain undergoing complete lysis when exposed to low fluoride for a moderate amount of time, and biochemical purification the S. mutans CLCF transporter and functional reconstitution establishes that the functional protein is a dimer encoded by a single gene. Together, these findings suggest that fluoride export by oral pathogens can be targeted by specific inhibitors to restore biofilm symbiosis in dental biofilms, and that S. mutans is especially susceptible to fluoride toxicity.
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Affiliation(s)
- Aditya Banerjee
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chia-Yu Kang
- Program in Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Minjun An
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - B Ben Koff
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sham Sunder
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Anuj Kumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Livia M A Tenuta
- School of Dentistry, University of Michigan, Ann Arbor, MI 48109, USA
| | - Randy B Stockbridge
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USA
- Program in Biophysics, University of Michigan, Ann Arbor, MI 48109, USA
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Howell SEI, Kumar P, da Costa J, Haraszthy V, Ioannidou E, MacDonnell W, Tenuta LMA, Frazier K, Rockman R, Vinh R. Teledentistry adoption and applications: An American Dental Association Clinical Evaluators Panel survey. J Am Dent Assoc 2023; 154:856-857.e2. [PMID: 37634916 DOI: 10.1016/j.adaj.2023.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 06/02/2023] [Indexed: 08/29/2023]
Abstract
BACKGROUND The rise of teleworking technologies has affected various industries, including dentistry. Although some dentists have used it for some time, many are discovering the benefits of incorporating this technology to complement their existing patient care capabilities. METHODS To assess how clinicians are using teledentistry in their practices, an electronic survey was developed and deployed to the American Dental Association Clinical Evaluators (ACE) Panel on February 27, 2023. The survey link remained open for 2 weeks. Nonrespondents received reminders after 1 week. RESULTS Of the 244 respondents (24% response rate), 30% use teledentistry in their practices, with more than one-half of those using synchronous (53%) or asynchronous teledentistry (63%). The most common reasons for incorporating teledentistry were increased convenience for patients (53%), COVID-19 (50%), and increased accessibility to providers (39%). Teledentistry can help serve patients of all ages (the lowest represented age group [0-5 years] had 42% of dentists treating them) and distances, with 63% of teledentistry patients fewer than 20 miles away. Most users adopted teledentistry within the past 3 years and use it fewer than 5 hours per month. Benefits cited include a reduced number of in-person patient visits (63%) and increased access and quality of care (57%). Among nonusers, 60% felt there was no need, and 39% had concerns with reimbursement. CONCLUSIONS Teledentistry has gained popularity in since the onset of the COVID-19 pandemic but may be underused, despite its potential to benefit a wider range of patients and applications than many believe. PRACTICAL IMPLICATIONS Education on the capabilities and benefits of teledentistry may help increase adoption and improve patient care.
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Tenuta LMA, Nóbrega DF, Mei ML. Chapter 9.1: The Use of Fluorides in the Control of Coronal Caries. Monogr Oral Sci 2023; 31:129-148. [PMID: 37364557 DOI: 10.1159/000530564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Accepted: 11/09/2022] [Indexed: 06/28/2023]
Abstract
Fluoride is the main agent used to control dental caries, with a very successful history after its widespread implementation worldwide, resulting in significant caries declines around the globe. In this chapter, the mechanism of action and peculiarities of different methods of fluoride use are revised. Fluoride controls caries progression by interfering with the processes of mineral exchanges (demineralization, remineralization) to which teeth are frequently subjected upon exposure to dental biofilm and a diet rich in fermentable sugars. Because caries is a ubiquitous disease of modern societies, different strategies have been developed to successfully keep fluoride available in oral fluids: (1) community-based approaches, such as water fluoridation, in which fluoride is delivered to communities at very low levels; (2) individual-based approaches, such as fluoride toothpastes, in which fluoride is delivered at higher concentrations, directly into the oral cavity, in a convenient combination with the act of brushing teeth to remove dental biofilm; (3) professionally-delivered approaches, such as fluoride gels and varnishes, in which very-high concentration products react with teeth resulting in local fluoride reservoirs that release the ion for weeks/months; and (4) combinations of these approaches, such as the concomitant use of fluoridated water and toothpaste, or the use of professional fluorides in caries-active patients. In conclusion, this chapter reviews the different modalities of fluoride use for coronal caries control, and summarizes the combined application of these methods according to the best evidence available.
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Affiliation(s)
- Livia M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Diego F Nóbrega
- Professional Master Program in Health Research, Cesmac University Center, Maceió, Brazil
| | - May L Mei
- Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
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Jones NA, Bloembergen W, Tenuta LMA, Flannagan SE, Jones GW, Pan LC, Newton M, Clarkson BH, Lahann J, Bloembergen S, González-Cabezas C. Early occlusal caries detection using targeted fluorescent starch nanoparticles. J Dent 2022; 125:104243. [PMID: 35907441 DOI: 10.1016/j.jdent.2022.104243] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 07/19/2022] [Accepted: 07/22/2022] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVES We have previously shown fluorescent cationic starch nanoparticles (FCSNs) penetrate enamel surface porosity of active carious lesions, potentially aiding their detection. Here, we evaluate the in vitro diagnostic accuracy of FCSNs in detecting occlusal caries compared to histologic reference standard. METHODS 100 extracted human teeth were selected with sound (50), or either non-cavitated (25) or cavitated (25) lesions. A region of interest (ROI) on the occlusal surface was assessed for fluorescence by two independent examiners, after immersion in FCSN solution, water rinse, and illumination by dental curing lamp viewed through orange UV-filter glasses. ROIs were sectioned and evaluated by histology (Downer Criteria) as a gold standard for caries presence. Cohen's Kappa was determined for inter- and intra-examiner agreement, and sensitivity, specificity, and area under the curve of Receiver Operator Curves (ROCAUC) were calculated. The analysis was repeated for the subset of "early" lesions, defined as being limited to enamel. RESULTS FCSN use resulted in substantial inter-user (k=0.74±0.07), and high intra-user agreement (k=0.80±0.06; 0.94±0.03, by examiner). Sensitivity, specificity and ROCAUC for FCSNs were 88.9%; 94.6%; 0.92±0.06 for all, and 76.9%, 94.6%, and 0.86±0.10 for early lesions. In post hoc analysis, sensitivity seemed to be greater with the FCSN than the expert visual exam, particularly for early lesions. CONCLUSIONS/CLINICAL SIGNIFICANCE FCSNs are a reproducible and accurate novel technology for occlusal caries detection, with high sensitivity and specificity compared to histology. Future clinical validation is necessary. FCSNs can improve early caries detection and shift treatment towards non-invasive approaches, improving oral health.
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Affiliation(s)
- Nathan A Jones
- GreenMark Biomedical Inc., 1600 Huron Parkway Building 520, Room 2399, Ann Arbor, MI 48109, United States.
| | - Wendy Bloembergen
- GreenMark Biomedical Inc., 1600 Huron Parkway Building 520, Room 2399, Ann Arbor, MI 48109, United States
| | - Livia M A Tenuta
- University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Susan E Flannagan
- University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Glenn W Jones
- Saba University School of Medicine, Devens, MA, United States
| | - Li-Chi Pan
- GreenMark Biomedical Inc., 1600 Huron Parkway Building 520, Room 2399, Ann Arbor, MI 48109, United States
| | - Mariah Newton
- GreenMark Biomedical Inc., 1600 Huron Parkway Building 520, Room 2399, Ann Arbor, MI 48109, United States
| | - Brian H Clarkson
- University of Michigan School of Dentistry, Ann Arbor, MI, United States
| | - Joerg Lahann
- Department of Chemical Engineering and Biointerfaces Institute, University of Michigan, Ann Arbor, MI, United States
| | - Steven Bloembergen
- GreenMark Biomedical Inc., 1600 Huron Parkway Building 520, Room 2399, Ann Arbor, MI 48109, United States
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Fernández CE, Brandao ACS, Bícego-Pereira EC, Del Bel Cury AA, Cury JA, Tenuta LMA. Effect of pH and titratable acidity on enamel and dentine erosion. Clin Oral Investig 2022; 26:5867-5873. [PMID: 35588021 DOI: 10.1007/s00784-022-04544-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 05/11/2022] [Indexed: 11/27/2022]
Abstract
OBJECTIVES The relative effect of pH and titratable acidity on tooth erosion remains unclear. We determined the effect of both properties on in vivo salivary pH recovery and on enamel and dentine early erosion in situ. METHODS Solutions simulating acidic beverages with different pHs (2.5 or 3.5) and titratable acidities (0, 25, or 100 mM citric acid) were tested. In an in vivo study (n = 20 participants), the salivary pH was determined before, during, and up to 2 min after exposure to the tested solutions. In situ, 12 participants exposed enamel and root dentine slabs to the tested solutions simulating a beverage consumption; early erosion was assessed by percentage of surface hardness loss (%SHL). Groups were compared by ANOVA (p < 0.05). RESULTS Saliva pH was lower after exposure to solutions at pH 2.5, irrespective of titratable acidity; pH recovery took longer for solutions with higher titratable acidities, irrespective of their pHs. In situ, the highest %SHL was observed for the solution with lower pH and higher titratable acidities. The addition of citric acid increased the %SHL by 2.5-3 times in enamel, and at least 5 times in dentine. CONCLUSIONS Both pH and titratable acidity may play a role on the erosive potential of acidic beverages. CLINICAL RELEVANCE Acidic beverages with lower pHs promote erosion by an initial acid etching of the surface; those with a higher titratable acidity slow down the salivary pH recovery. Both properties contribute to the overall erosive potential.
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Affiliation(s)
- Constanza E Fernández
- Cariology Unit, Department Oral Rehabilitation, Faculty Health Sciences, University of Talca, Talca, Chile
| | | | | | | | - Jaime A Cury
- Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Livia M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, 1011 N. University Ave. Room 5223, MI, 48109-1078, Ann Arbor, USA.
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Abstract
INTRODUCTION The historical separation between medicine and dentistry has resulted in the creation of separate health records, which have the potential to negatively impact patient care and safety. Of particular importance, errors or omissions in medication lists in separate electronic health records (EHRs) may lead to medical errors and serious adverse outcomes. OBJECTIVE This study aimed to compare medication lists reported in the EHRs of active patients treated by both the University of Michigan School of Dentistry and Michigan Medicine to determine if differences exist. METHODS In this cohort study, EHRs of a population of 159,733 patients that the University of Michigan medical and dental clinics share in common were investigated for agreement in the reporting of 16 medications. After exclusion of minors and patients not seen in the last 5 y, records of 27,277 patients were examined. RESULTS The maximum percentage of agreement in medications reported in both records was 52% for levothyroxine, and the minimum was 7% for sildenafil. The medical record had a significantly higher number of unique medications than the dental record, suggesting higher underreporting in the dental setting. CONCLUSION The lack of agreement in the report of medications with serious dental and medical implications argues in favor of unification of records and use of available technology to increase accurate medication reporting. KNOWLEDGE TRANSFER STATEMENT The results demonstrate a lack of agreement between medications reported in medical and dental records, which can have serious implications to patients' health. A unified health record, employing available technology to increase accurate medication reporting, would mitigate this problem.
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Affiliation(s)
- L M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - C Canady
- Office of Dental Informatics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - R M Eber
- Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - L Johnson
- Office of Dental Informatics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.,Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
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Abstract
Root caries progression is aggravated by hyposalivation, which can accelerate the conversion of a dental biofilm from having a symbiotic microbial relationship with the host (predominance of nonaciduric species) to a dysbiotic one (dominated by aciduric species). Using a mathematical model previously employed to investigate factors associated with biofilm dysbiosis, we systematically explored the deleterious effect of hyposalivation on the composition of the biofilm and the risk of root dentin demineralization. By varying the clearance half-times of sugar (i.e., readily fermented dietary carbohydrates), we simulated hyposalivation and investigated its effect on 1) the time that the biofilm pH spends below the minimum for dentin or enamel demineralization and 2) the conversion of the biofilm from a symbiotic to dysbiotic composition. The effect of increasing sugar clearance half-times on the time that the biofilm pH is below the threshold for demineralization was more pronounced for dentin than for enamel (e.g., increasing the clearance half-time from 2 to 6 min doubled the time that the biofilm pH was below the threshold for dentin demineralization). The effect on biofilm composition assessed at 50 d showed that the conversion from a symbiotic to a dysbiotic biofilm happened around a frequency of 6 sugar intakes per day when the clearance half-time was 2 min but only 3 sugar intakes per day when the clearance half-time was 6 min. Taken together, the results confirm the profound effect that prolonged sugar clearance has on the dynamics of dental biofilm composition and the subsequent risk of root caries. This in silico model should be applied to study how interventions that alter salivary clearance rates or modify biofilm pH can affect clinical conditions such as root caries.
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Affiliation(s)
- D Head
- School of Computing, University of Leeds, Leeds, UK
| | - P D Marsh
- Division of Oral Biology, School of Dentistry, Wellcome Trust Brenner Building, University of Leeds, St. James University Hospital, Leeds, UK
| | - D A Devine
- Division of Oral Biology, School of Dentistry, Wellcome Trust Brenner Building, University of Leeds, St. James University Hospital, Leeds, UK
| | - L M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
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Souza JGS, Del Bel Cury AA, Cury JA, Tenuta LMA. On the release of fluoride from biofilm reservoirs during a cariogenic challenge: an in situ study. Biofouling 2020; 36:870-876. [PMID: 32993384 DOI: 10.1080/08927014.2020.1826455] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/07/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
Biofilm fluoride reservoirs may be a source of fluoride to the fluid phase during a sugar challenge reducing tooth mineral loss. However, the evidence for that is conflicting and has not been studied in biofilms containing different fluoride levels. In order to test fluoride release from biofilms with distinct fluoride concentrations, biofilms were grown in situ exposed to a combination of placebo, calcium and fluoride rinses forming biofilms with no (fluoride-free rinses), low (fluoride-only rinses) or high (calcium followed by fluoride rinses) fluoride concentrations, and collected before and 5 min after a sucrose challenge. Rinsing with fluoride increased fluoride concentration in the biofilm (p < 0.05), mainly when a calcium pre-rinse was used before the fluoride (p < 0.05). However, after a sugar challenge, no significant increase in the biofilm fluid fluoride concentration was observed, even in the fluoride-rich biofilms (p > 0.05). Fluoride-rich biofilms do not release fluoride to the fluid phase during a sugar challenge.
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Affiliation(s)
- João G S Souza
- Piracicaba Dental School, UNICAMP, Piracicaba, SP, Brazil
| | | | - Jaime A Cury
- Piracicaba Dental School, UNICAMP, Piracicaba, SP, Brazil
| | - Livia M A Tenuta
- Piracicaba Dental School, UNICAMP, Piracicaba, SP, Brazil
- Department of Cariology, Restorative Sciences & Endodontics, School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
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12
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Abstract
Caries lesions result from the interaction between dental biofilm and sugars. Since the biofilm is an important component in the etiology of the disease, biofilm models have been developed to study the cariogenicity of dietary sugars, as well as the anticaries effect of substances. Two of such models, termed as "static" or "continuous flow," are described in details here together with their advantages, limitations, and applications.
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Affiliation(s)
- Bennett T Amaechi
- Department of Comprehensive Dentistry, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA.
| | - Livia M A Tenuta
- Department of Cariology, Restorative Sciences and Endodontics, School of Dentistry, University of Michigan, Ann Arbor, MI, USA
| | - Antonio P Ricomini Filho
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
| | - Jaime A Cury
- Department of Physiological Sciences, Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
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13
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Figuero E, Nóbrega DF, García-Gargallo M, Tenuta LMA, Herrera D, Carvalho JC. Mechanical and chemical plaque control in the simultaneous management of gingivitis and caries: a systematic review. J Clin Periodontol 2018; 44 Suppl 18:S116-S134. [PMID: 28266113 DOI: 10.1111/jcpe.12674] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2016] [Indexed: 11/29/2022]
Abstract
AIM To report the evidence on the effect of mechanical and/or chemical plaque control in the simultaneous management of gingivitis and caries. MATERIAL AND METHODS A protocol was designed to identify randomized (RCTs) and controlled (CCTs) clinical trials, cohort studies and prospective case series (PCS), with at least 6 months of follow-up, reporting on plaque, gingivitis and caries. Relevant information was extracted from full papers, including quality and risk of bias. Meta-analyses were performed whenever possible. RESULTS After the screening of 1,373 titles, 15 RCTs, 10 CCTs and 2 PCS were included. Low to moderate evidence support that combined professional and self-performed mechanical plaque control significantly reduces standardized plaque index [n = 4; weighted mean difference (WMD) = 1.294; 95% CI (0.445; 2.144); p = 0.003] and gingivitis scores [n = 4; WMD = 1.728; 95% CI (0.631; 2.825); p = 0.002]. The addition of fluoride to mechanical plaque control is relevant for caries management [n = 5; WMD = 1.159; 95% CI (0.145; 2.172); p = 0.025] while chlorhexidine rinses are relevant for gingivitis. CONCLUSION Mechanical plaque control procedures are effective in reducing plaque and gingivitis. The addition of fluoride to mechanical plaque control is significant for caries management. Chlorhexidine rinse has a positive effect on gingivitis and inconclusive role in caries.
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Affiliation(s)
- Elena Figuero
- ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain
| | - Diego F Nóbrega
- Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - María García-Gargallo
- ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain
| | - Livia M A Tenuta
- Piracicaba Dental School, University of Campinas (UNICAMP), Piracicaba, Brazil
| | - David Herrera
- ETEP (Etiology and Therapy of Periodontal Diseases) Research Group, University Complutense, Madrid, Spain
| | - Joana C Carvalho
- Faculty of Medicine and Dentistry, Catholic University of Louvain, Brussels, Belgium
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14
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Lima CV, Tenuta LMA, Cury JA. Fluoride Increase in Saliva and Dental Biofilm due to a Meal Prepared with Fluoridated Water or Salt: A Crossover Clinical Study. Caries Res 2018; 53:41-48. [PMID: 29879711 DOI: 10.1159/000489132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 04/10/2018] [Indexed: 11/19/2022] Open
Abstract
Knowledge about fluoride delivery to oral fluids from foods cooked with fluoridated water and salt is scarce, and no study has evaluated fluoride concentrations in saliva or biofilm during meal consumption. In this randomized double-blind crossover study, 12 volunteers ingested meals (rice, beans, meat, and legumes) prepared with nonfluoridated water and salt (control group), fluoridated water (0.70 mg F/L; water group), and fluoridated salt (183.7 mg F/kg; salt group). Whole saliva was collected before meal ingestion, during mastication, and up to 2 h after meal ingestion. Dental biofilm was collected before and immediately after meal ingestion. Fluoride concentrations in saliva and dental biofilm were determined by an ion-specific electrode. The mean (±standard deviation; n = 4) fluoride concentrations in meals prepared for the control, water, and salt groups were 0.039 ± 0.01, 0.43 ± 0.04, and 1.71 ± 0.32 μg F/g, respectively. The three groups had significantly different fluoride concentrations in saliva collected during mastication (p < 0.0001) and after meal ingestion (p < 0.04; salt > water > control). The fluoride concentration in saliva returned to baseline 30 min after meal ingestion in the water group but remained high for up to 2 h in the salt group (p = 0.002). The fluoride concentration in biofilm fluid differed only between the salt and control groups (p = 0.008). The mastication of foods cooked with fluoridated water and salt increases fluoride concentrations in oral fluids and may contribute to the local effect of these community-based fluoride interventions on caries control.
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Affiliation(s)
- Carolina V Lima
- Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
| | - Livia M A Tenuta
- Piracicaba Dental School, University of Campinas, Piracicaba, Brazil.,School of Dentistry, University of Michigan, Ann Arbor, Michigan, USA
| | - Jaime A Cury
- Piracicaba Dental School, University of Campinas, Piracicaba,
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15
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Abstract
A low-fluoride (F) dentifrice has been recommended to reduce the risk of dental fluorosis, but its anti-caries efficacy is questionable compared with that of conventional dentrifices (1000–1100 μg F/g). The tested hypothesis was that conventional dentifrices might be safe if used soon after meals, since food interferes with F absorption. In a crossover, double-blind study, 11 volunteers ingested a dentifrice slurry containing 0 (placebo), 550 (low F), or 1100 μg F/g in 3 gastric content situations: on fasting, or 15 min after breakfast or lunch. F was analyzed in saliva and 24-hour urine samples. The conventional dentifrice ingested after lunch resulted in only 10% higher F absorption than the low-F ingested on fasting. Analysis of the data suggests that the risk of fluorosis could be reduced by the use of either a low-F dentifrice or a conventional dentifrice, if toothbrushing occurred soon after meals.
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Affiliation(s)
- J A Cury
- Faculty of Dentistry of Piracicaba, UNICAMP, Av. Limeira 901, 13414-903, Piracicaba, SP, Brazil.
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16
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Abstract
Calcium (Ca), inorganic phosphorus (Pi), and fluoride (F) concentrations are low in the whole plaque biofilm formed under exposure to sucrose. It was hypothesized that this would be reflected in the biofilm fluid, where these low values should greatly influence the de/remineralization process. Dental biofilms were formed in situ over enamel blocks mounted in palatal appliances and exposed 8 times/day to distilled water, glucose+fructose, or sucrose solutions for 14 days. While Ca, Pi, and F concentrations in the whole biofilms were significantly lower in the glucose+fructose and sucrose groups, no effect on biofilm fluid was observed, even after a cariogenic challenge. An increase in whole biofilm mineral ions was observed 24 hrs after the carbohydrate treatments were suspended, but this effect was also not observed in the fluid. These results suggest that there is a homeostatic mechanism that maintains biofilm fluid mineral ion concentration, regardless of its total concentration in the whole biofilm.
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Affiliation(s)
- L M A Tenuta
- Faculty of Dentistry of Piracicaba, UNICAMP, Av. Limeira 901, 13414-903, Piracicaba, SP, Brazil
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17
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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18
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Souza MLR, Cury JA, Tenuta LMA, Zhang YP, Mateo LR, Cummins D, Ellwood RP. Comparación de la Eficacia de un Dentífrico que Contiene Arginina al 1.5% y 1450ppm de Fluoruro con la de un Dentífrico que Contiene 1450ppm de Fluoruro Solamente, en el Manejo de la Caries Radicular Primaria. J Dent 2013:S0300-5712(13)00279-0. [PMID: 24161716 DOI: 10.1016/j.jdent.2013.10.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- M L R Souza
- Departamento de Odontología Social, Facultad de Odontología de Piracicaba, Universidad de Campinas (UNICAMP), Piracicaba, SP, Brasil
| | - J A Cury
- Departamento de Bioquímica, Facultad de Odontología de Piracicaba, Universidad de Campinas (UNICAMP), Piracicaba, SP, Brasil
| | - L M A Tenuta
- Departamento de Bioquímica, Facultad de Odontología de Piracicaba, Universidad de Campinas (UNICAMP), Piracicaba, SP, Brasil
| | - Y P Zhang
- Centro de Tecnología de Colgate Palmolive, River Road, Piscataway, NJ, EE.UU
| | - L R Mateo
- LRM Consultoría en Estadística, Hoboken, NJ, EE.UU
| | - D Cummins
- Centro de Tecnología de Colgate Palmolive, River Road, Piscataway, NJ, EE.UU
| | - R P Ellwood
- Unidad de Salud Dental, Skelton House, Manchester Science Park, Lloyd St North, Manchester M15 6SH, Reino Unido.
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19
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Modesto A, Klein O, Tenuta LMA, Gerlach RF, Vieira AR. Summary of the IADR Cariology Research, Craniofacial Biology, and Mineralized Tissue Groups Symposium, Iguaçu Falls, Brazil, June 2012: Gene-environment Interactions and Epigenetics in Oral Diseases: Enamel Formation and its Clinical Impact on Tooth Defects, Caries, and Erosion. Dent 3000 2013; 1. [PMID: 25392764 DOI: 10.5195/d3000.2013.16] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Characteristics of enamel may influence or modulate individual susceptibility to caries and erosion. These characteristics are defined during development, which is under strict genetic control, but can easily be modified in many ways by environmental factors. In the symposium, translational aspects of embryology, biochemistry, and genetics of amelogenesis were presented. The symposium provided unique insight into how basic sciences integrate with clinically relevant problems. The need for improved understanding of risks at the individual level, taking into consideration both environmental exposures and genetic background, was presented. The symposium was divided into four stepwise and interconnected topics as follows: 1) The Many Faces of Enamel Development; 2) Enamel Pathogenesis: Biochemistry Lessons; 3) Environmental Factors on Enamel Formation; and, 4) Genetic Variation in Enamel Formation Genes.
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Affiliation(s)
- Adriana Modesto
- University of Pittsburgh, School of Dental Medicine, Pittsburgh, PA, USA
| | - Ophir Klein
- University of California, School of Dentistry, San Francisco, CA, USA
| | - Livia M A Tenuta
- University of Campinas, Piracicaba Dental School, Piracicaba, SP, Brazil
| | | | - Alexandre R Vieira
- University of Pittsburgh, School of Dental Medicine, Pittsburgh, PA, USA
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20
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Correia MF, Tenuta LMA, Del Bel Cury AA, Cury JA. Mineral ions in the fluid of biofilms formed on enamel and dentine shortly after sugar challenge. Caries Res 2012; 46:408-12. [PMID: 22710251 DOI: 10.1159/000339376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2011] [Accepted: 04/17/2012] [Indexed: 11/19/2022] Open
Abstract
To test the effect of distinct solubilities of dentine and enamel on mineral ion concentration in the biofilm fluid during a sugar-induced pH drop, dental biofilms were formed in situ for 4 days on acrylic (control), dentine or enamel. On the 5th day, they were treated with water (control) or 20% glucose and collected 5 min later. Significantly lower pH values and higher calcium concentrations were found in the biofilm fluid after glucose exposure, without significant differences among the three substrates. During pH drop, biofilm reservoirs release calcium to the fluid, masking the differential solubility between enamel and dentine.
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Affiliation(s)
- M F Correia
- Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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21
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Abstract
Professionally applied topical fluoride varnish, gel, and solution have been shown to be effective in preventing and in arresting dental caries. Their use in different countries in Asia varies greatly and may not correlate with the dental caries situation of the populations in the countries. In the higher-income countries, use of fluoride varnish and gel is common among dental professionals. In contrast, the use of professionally administered topical fluorides is not common in the lower-income countries. Fluoride varnish, being easy to apply and safe, has been the preferred agent for the prevention of early childhood caries, which is prevalent in many developing countries in Asia. The relatively high cost of professionally administered fluoride agents and the shortage of a dental workforce, especially in lower income countries, have hampered the widespread adoption of these effective caries prevention methods in the private and public dental services. Government health policies should be pursued to lower the cost of treatment, either through incentives for local production and/or elimination of taxes and tariffs on imported fluoride products.
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Affiliation(s)
- E C M Lo
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
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22
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Lippert F, Zero DT, Tenuta LMA. Pessan et al. (2010) failed to recognize several important aspects. J Dent Res 2010; 90:5; author reply 6. [PMID: 21178117 DOI: 10.1177/0022034510385244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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23
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Vale GC, Tabchoury CPM, Del Bel Cury AA, Tenuta LMA, ten Cate JM, Cury JA. APF and dentifrice effect on root dentin demineralization and biofilm. J Dent Res 2010; 90:77-81. [PMID: 20929723 DOI: 10.1177/0022034510383428] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Because dentin is more caries-susceptible than enamel, its demineralization may be more influenced by additional fluoride (F). We hypothesized that a combination of professional F, applied as acidulated phosphate F (APF), and use of 1100-ppm-F dentifrice would provide additional protection for dentin compared with 1100-ppm-F alone. Twelve adult volunteers wore palatal appliances containing root dentin slabs, which were subjected, during 4 experimental phases of 7 days each, to biofilm accumulation and sucrose exposure 8x/day. The volunteers were randomly assigned to the following treatments: placebo dentifrice (PD), 1100-ppm-F dentifrice (FD), APF + PD, and APF+FD. APF gel (1.23% F) was applied to the slabs once at the beginning of the experimental phase, and the dentifrices were used 3x/day. APF and FD increased F concentration in biofilm fluid and reduced root dentin demineralization, presenting an additive effect. Analysis of the data suggests that the combination of APF gel application and daily regular use of 1100-ppm-F dentifrice may provide additional protection against root caries compared with the dentifrice alone.
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Affiliation(s)
- G C Vale
- Piracicaba Dental School, University of Campinas, Piracicaba, SP, Brazil
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24
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Cury JA, Do Amaral RC, Tenuta LMA, Del Bel Cury AA, Tabchoury CPM. Low-fluoride toothpaste and deciduous enamel demineralization under biofilm accumulation and sucrose exposure. Eur J Oral Sci 2010; 118:370-5. [DOI: 10.1111/j.1600-0722.2010.00745.x] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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25
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Vogel GL, Tenuta LMA, Schumacher GE, Chow LC. No calcium-fluoride-like deposits detected in plaque shortly after a sodium fluoride mouthrinse. Caries Res 2010; 44:108-15. [PMID: 20185917 DOI: 10.1159/000287239] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2009] [Accepted: 01/04/2010] [Indexed: 11/19/2022] Open
Abstract
Plaque 'calcium-fluoride-like' (CaF(2)-like) and fluoride deposits held by biological/bacterial calcium fluoride (Ca-F) bonds appear to be the source of cariostatic concentrations of fluoride in plaque fluid. The aim of this study was to quantify the amounts of plaque fluoride held in these reservoirs after a sodium fluoride rinse. 30 and 60 min after a 228 microg/g fluoride rinse, plaque samples were collected from 11 volunteers. Each sample was homogenized, split into 2 aliquots (aliquots 1 and 2), centrifuged, and the recovered plaque fluid combined and analyzed using microelectrodes. The plaque mass from aliquot 1 was retained. The plaque mass from aliquot 2 was extracted several times with a solution having the same fluoride, calcium and pH as the plaque fluid in order to extract the plaque CaF(2)-like deposits. The total fluoride in both aliquots was then determined. In a second experiment, the extraction completeness was examined by applying the above procedure to in vitro precipitates containing known amounts of CaF(2)-like deposits. Nearly identical fluoride concentrations were found in both plaque aliquots. The extraction of the CaF(2)-like precipitates formed in vitro removed more than 80% of these deposits. The results suggest that either CaF(2)-like deposits were not formed in plaque or, if these deposits had been formed, they were rapidly lost. The inability to form persistent amounts of CaF(2)-like deposits in plaque may account for the relatively rapid loss of plaque fluid fluoride after the use of conventional fluoride dentifrices or rinses.
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Affiliation(s)
- G L Vogel
- American Dental Association Foundation, Paffenbarger Research Center, Gaithersburg, MD 20899-8546, USA. jvogel @ nist.gov
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26
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Tenuta LMA, Zamataro CB, Del Bel Cury AA, Tabchoury CPM, Cury JA. Mechanism of fluoride dentifrice effect on enamel demineralization. Caries Res 2009; 43:278-85. [PMID: 19439949 DOI: 10.1159/000217860] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2008] [Accepted: 03/10/2009] [Indexed: 11/19/2022] Open
Abstract
Although the anticaries effect of fluoride (F) dentifrices is clearly established, the relative importance of F taken up by dental plaque not removed by brushing and of F products (CaF(2)-like) formed on totally cleaned enamel for the subsequent inhibition of demineralization is not known. Both effects were evaluated using conventional (1,100 microg F/g) and low-F concentration (500 microg F/g) dentifrices in a randomized, crossover, double-blind in situ study. Enamel blocks not treated or pretreated with the dentifrices to form CaF(2)-like deposits were mounted in palatal appliances in contact with a Streptococcus mutans test plaque. Volunteers brushed with non-F (negative control), low-F or conventional dentifrices and inserted the appliance in the mouth. F concentration in the fluid and solid phases of the test plaque was determined after 30 min, and a rinse with 20% sucrose solution was performed. After additional 45 min, plaque was collected and the loss of surface hardness at different test-plaque depths was measured. CaF(2)-like deposition on enamel and F taken up by plaque due to the use of F dentifrices were able to significantly increase F concentration in the fluid phase of the test plaque, but only the latter significantly reduced the loss of hardness because of the 20-30 times higher F concentration. Also, significant differences between the low-F and conventional dentifrices were observed for F on enamel, in plaque and on the subsequent loss of hardness. The results suggest that uptake of F by dental plaque not removed by brushing may be the main cause of the anticaries effect of F dentifrices.
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Affiliation(s)
- L M A Tenuta
- Piracicaba Dental School, UNICAMP, Piracicaba, Brazil.
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27
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Aires CP, Del Bel Cury AA, Tenuta LMA, Klein MI, Koo H, Duarte S, Cury JA. Effect of starch and sucrose on dental biofilm formation and on root dentine demineralization. Caries Res 2008; 42:380-6. [PMID: 18781066 DOI: 10.1159/000154783] [Citation(s) in RCA: 100] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2008] [Accepted: 07/07/2008] [Indexed: 11/19/2022] Open
Abstract
The cariogenicity of starch alone or in combination with sucrose is controversial and the effect on dentine demineralization and on the dental biofilm formed has not been explored under controlled conditions. A crossover, single-blind study was conducted in four steps of 14 days each, during which 11 volunteers wore palatal appliance containing 10 slabs of root dentine to which the following treatments were applied extraorally: 2% starch gel-like solution (starch group); 10% sucrose solution (sucrose group); a solution containing 2% starch and 10% sucrose (starch + sucrose group), or 2% starch solution followed by 10% sucrose solution (starch --> sucrose group). On the 14th day of each phase the biofilms were collected for biochemical and microbiological analyses, and dentine demineralization was assessed by hardness. A higher demineralization was found in dentine exposed to sucrose and starch sucrose combinations than to starch alone (p < 0.01), but the sucrose-containing groups did not differ significantly from each other (p > 0.05). The concentrations of soluble and insoluble extracellular polysaccharides (EPS), and the proportion of insoluble EPS, were lower in the biofilm formed in presence of starch (p < 0.01) than in those formed in the presence of sucrose or sucrose/starch combinations; however, no significant difference was observed among the groups containing sucrose (p > 0.05). RNA was successfully isolated and purified from in situ biofilms and only biofilms formed in response to sucrose and starch/sucrose combinations showed detectable levels of gtfB and gtfC mRNA. The findings suggest that the combination of starch with sucrose may not be more cariogenic to dentine than sucrose alone.
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Affiliation(s)
- C P Aires
- Piracicaba Dental School, University of Campinas, Piracicaba, Brazil
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28
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Ccahuana-Vásquez RA, Tabchoury CPM, Tenuta LMA, Del Bel Cury AA, Vale GC, Cury JA. Effect of Frequency of Sucrose Exposure on Dental Biofilm Composition and Enamel Demineralization in the Presence of Fluoride. Caries Res 2006; 41:9-15. [PMID: 17167254 DOI: 10.1159/000096100] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 07/19/2006] [Indexed: 11/19/2022] Open
Abstract
It has been suggested that enamel would resist higher frequencies of sucrose exposure if fluoride from water or dentifrice is being used. However, the effect of increasing frequencies of sugar on dental biofilm composition is not well known. Ten volunteers living in a fluoridated area wore palatal appliances bearing human enamel slabs during 14 days. The slabs were exposed to 20% sucrose solution 0 (control), 2, 4, 6, 8 or 10 times/day and the volunteers used fluoride dentifrice 3 times/day. Enamel demineralization was significantly greater than control for sucrose frequencies higher than 6 times/day. However, biofilm mass, total microbiota, total streptococci, lactobacilli counts and insoluble extracellular polysaccharide concentration increased, while Ca, P(i) and F concentration in whole biofilm decreased significantly, with frequencies of sucrose exposure lower than 6 times/day. The findings confirm that fluoride can reduce enamel demineralization if sucrose consumption is not higher than 6 times/day, but changes in the biochemical and microbiological composition of the biofilm are observed with lower frequencies of sucrose use.
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29
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Tenuta LMA, Ricomini Filho AP, Del Bel Cury AA, Cury JA. Effect of Sucrose on the Selection of Mutans Streptococci and Lactobacilli in Dental Biofilm Formedin situ. Caries Res 2006; 40:546-9. [PMID: 17063028 DOI: 10.1159/000095656] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2006] [Accepted: 04/03/2006] [Indexed: 11/19/2022] Open
Abstract
Microorganisms are selected in dental biofilm by the acidic environment created by sugar fermentation, but the effect of extracellular polysaccharide (EPS) on the counts of cariogenic bacteria is not clear. Dental biofilm was formed in situ for 13 days under exposure 8 times a day to distilled-deionized water, glucose + fructose or sucrose solutions. Mutans streptococci (MS) counts were not different among the groups, but lactobacilli (LB) were significantly higher in glucose + fructose and sucrose groups, without significant difference between them, irrespective of the higher insoluble EPS concentration in the sucrose biofilm matrix. The data suggest that exposure to sugar is more relevant for the predominance of LB in dental biofilm than for MS and that insoluble EPS does not change the counts of these microorganisms in the biofilm.
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Affiliation(s)
- L M A Tenuta
- Faculty of Dentistry of Piracicaba, UNICAMP, Piracicaba, SP, Brazil
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30
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Abstract
Since in vitro and animal studies suggest that the combination of starch with sucrose may be more cariogenic than sucrose alone, the study assessed in situ the effects of this association applied in vitro on the acidogenicity, biochemical and microbiological composition of dental biofilm, as well as on enamel demineralization. During two phases of 14 d each, fifteen volunteers wore palatal appliances containing blocks of human deciduous enamel, which were extra-orally submitted to four groups of treatments: water (negative control, T1); 2 % starch (T2); 10 % sucrose (T3); and 2 % starch+10 % sucrose (T4). The solutions were dripped onto the blocks eight times per day. The biofilm formed on the blocks was analysed with regard to amylase activity, acidogenicity, and biochemical and microbiological composition. Demineralization was determined on enamel by cross-sectional microhardness. The greatest mineral loss was observed for the association starch+sucrose (P<0.05). Also, this association resulted in the highest lactobacillus count in the biofilm formed (P<0.05). In conclusion, the findings suggest that a small amount of added starch increases the cariogenic potential of sucrose.
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Affiliation(s)
- Cecilia C C Ribeiro
- Faculty of Dentistry of Piracicaba, University of Campinas, Av. Limeira 901, CEP 13414-903, Piracicaba, São Paulo, Brazil
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