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de-Sousa ET, Lima-Holanda AT, Nobre-Dos-Santos M. Carbonic anhydrase VI activity in saliva and biofilm can predict early childhood caries: A preliminary study. Int J Paediatr Dent 2021; 31:361-371. [PMID: 32815217 DOI: 10.1111/ipd.12717] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 06/05/2020] [Accepted: 07/29/2020] [Indexed: 01/20/2023]
Abstract
AIM This study aimed to investigate whether carbonic anhydrase VI activity (CA VIACT ), pH, and buffering capacity (BC) in saliva and biofilm could predict the number of lesion occurrence and early childhood caries (ECC). DESIGN A cross-sectional study was performed in a sample of 44 children aged 4 to 5 years who were examined regarding their caries status (dmfs + active white spot lesions-WSL) and allocated into two groups: ECC and caries-free (CF). Saliva and biofilm were collected to determine pH, BC, and CA VIACT . Data were analyzed using the Student t test, and multiple linear regression and logistic regression analyses followed by the ROC curve. RESULTS Children with ECC exhibited lower pH and BC in saliva and a higher CA VIACT in both saliva and biofilm. Only saliva pH could predict the dmfs + active WSL. In biofilm, if CA VIACT is increased by one pixel/µg, 0.85 ± 0.28 increase is expected in the number of active WSL. Salivary pH and CA VIACT in saliva and biofilm had the power to predict ECC occurrence. CONCLUSION Changes in saliva pH and CA VIACT in biofilm predicted the number of lesion occurrence. Furthermore, CA VIACT in both saliva and biofilm can predict propensity for ECC.
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Affiliation(s)
- Emerson Tavares de-Sousa
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba-SP, Brazil
| | - Aline Tavares Lima-Holanda
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba-SP, Brazil
| | - Marinês Nobre-Dos-Santos
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Piracicaba-SP, Brazil
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The role of mechanical control of biofilm in the salivary pH after sucrose exposure in children with early childhood caries. Sci Rep 2021; 11:7496. [PMID: 33820926 PMCID: PMC8021547 DOI: 10.1038/s41598-021-86861-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Accepted: 03/15/2021] [Indexed: 01/20/2023] Open
Abstract
This quasi-experimental study sought to investigate if the mechanical control of biofilm (3-times-a-day) modifies the saliva’s ability to buffer the oral environment after 20% sucrose rinse (SR20%) in children with early childhood caries (ECC). Here, SR20% reduced the saliva’s pH in both groups and the mechanical control of biofilm had a greater effect on this parameter after SR20% in CF children. The mechanical control of biofilm evidenced a higher buffering capacity in CF children before SR20%, which was not observed after SR20%. Otherwise, the absence of mechanical control of biofilm showed that buffering capacity was comparable in the two groups before SR20%, whereas after SR20% the saliva’s buffering capacity of CF children was higher than ECC children. When biofilm was mechanically controlled, carbonic anhydrase VI activity did not change after SR20% whereas the absence of mechanical control of biofilm reduced this enzyme activity after SR20%. In conclusion, the mechanical control of biofilm did not change saliva’s ability to buffer the oral environment after SR20% in children with ECC. On the other hand, CF children appeared to regulate more effectively the saliva’s pH than ECC children while the absence of mechanical control of biofilm mediated their pH-modifying ability after SR20%.
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Florez Salamanca EJ, Dantas RM, Rodriguez MJ, Klein MI. Establishment of microcosm biofilm models that reproduce a cariogenic diet intake. BIOFOULING 2020; 36:1196-1209. [PMID: 33349045 DOI: 10.1080/08927014.2020.1862093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 12/02/2020] [Accepted: 12/03/2020] [Indexed: 06/12/2023]
Abstract
Biofilms were developed from human saliva on bovine enamel discs in four experimental conditions to investigate dental caries development: feast and famine (M1), abundance and scarcity (M2), three meals daily (M3), and three meals plus two snacks daily (M4). The main difference between these models was the diet for microbial growth. The evaluations included verifying the pH of the spent culture media and analyzing the enamel discs for demineralization (microhardness and roughness) and biofilms (biomass, viable populations of mutans streptococci, and total microbiota). Two major behaviors were observed: M1 and M2 promoted an acidic environment, while M3 and M4 maintained pH values closer to neutral. The demineralization process was slower in the neutral groups but more pronounced in M3, while a greater increase in microbiota and biomass was observed over time for both neutral groups. Thus, the M3 model was better at mimicking the oral environment that leads to demineralization.
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Affiliation(s)
- Elkin Jahir Florez Salamanca
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), School of Dentistry, Araraquara, São Paulo, Brazil
| | - Rayssa Mariana Dantas
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), School of Dentistry, Araraquara, São Paulo, Brazil
| | | | - Marlise Inêz Klein
- Department of Dental Materials and Prosthodontics, São Paulo State University (Unesp), School of Dentistry, Araraquara, São Paulo, Brazil
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Shi W, Tian J, Xu H, Wang G, Zhou Q, Qin M. Carbon source utilization patterns in dental plaque and microbial responses to sucrose, lactose, and phenylalanine consumption in severe early childhood caries. J Oral Microbiol 2020; 12:1782696. [PMID: 32944149 PMCID: PMC7482870 DOI: 10.1080/20002297.2020.1782696] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Background Severe early childhood caries (S-ECC) is mainly caused by the interaction of microbiota and environmental factors. However, the metabolic profiles of S-ECC microbial communities and the community-level microbial responses to carbohydrates and amino acids are poorly understood. Methods We collected supragingival plaques from 15 caries-free (CF) and 14 S-ECC children. Cultivation on Biolog AN microplates together with next-generation sequencing was used to analyze sole carbon source utilization patterns and microbial responses to sucrose, lactose and phenylalanine. Results S-ECC plaques had greater overall metabolic activity than those of CF ones. Comparing with CF, S-ECC plaques utilized more sucrose and lactose but less phenylalanine and then had greater response to carbohydrates. A remarkable increase of non-mutans Streptococci was observed in sucrose and lactose consumption. Lactose led to less differently distributed taxa than sucrose in both CF and S-ECC groups. Sucrose made the originally different S-ECC and CF communities eventually became similar to each other, but they remained dissimilar in lactose. Conclusion S-ECC plaques had more active interaction with cariogenic carbohydrates like sucrose and lactose than healthy plaques. We supported lactose has less cariogenicity compared with sucrose from microbial community structural aspect. Phenylalanine may have a potentially inhibitory effect on caries development.
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Affiliation(s)
- Weihua Shi
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Jing Tian
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - He Xu
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Guiyan Wang
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Qiong Zhou
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
| | - Man Qin
- Department of Pediatric Dentistry, Peking University School and Hospital of Stomatology, Beijing, China
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de Sousa ET, Lima-Holanda AT, Nobre-Dos-Santos M. Changes in the salivary electrolytic dynamic after sucrose exposure in children with Early Childhood Caries. Sci Rep 2020; 10:4146. [PMID: 32139791 PMCID: PMC7057989 DOI: 10.1038/s41598-020-61128-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2019] [Accepted: 02/18/2020] [Indexed: 01/01/2023] Open
Abstract
This study sought to explore if the effect of 20% sucrose rinse (SR) on the salivary electrolytic concentration of calcium (Ca2+), phosphate (Pi) and fluoride (F-) in children with Early Childhood Caries (ECC) is different from healthy children. Here, fifty-eight preschoolers aged 3 to 5 years were divided into 2 groups: caries-free (CF) and with ECC. Changes in saliva flow rate, pH and buffering capacity (BC), as well as in concentrations of Ca2+, Pi, and F-, and the degree of saturation in relation to hydroxyapatite (DSS HAp) and fluorapatite (DSS FAp) were evaluated. The pre-rinse [Ca2+] was higher in the ECC group in the CF group. A significant increase in [Ca2+] was demonstrated after SR in the CF group (p = 0.05). The [Pi] was reduced by 18% after SR in the ECC group (p = 0.007). The [F-] reduced in both groups after SR (p < 0.000). There was a moderate positive correlation between [Ca2+] and the DSS HAp and DSS FAp. Multivariate analysis showed that children with a higher [Ca2+] in pre-rinse saliva are more likely to have ECC. In conclusion, the effect of a 20% sucrose rinse on the electrolytic concentration of Ca2+, Pi and F- was different when children with ECC were compared with CF children.
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Affiliation(s)
- Emerson Tavares de Sousa
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Av. Limeira 901, Piracicaba, SP, CEP 13414-903, Brazil
| | - Aline Tavares Lima-Holanda
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Av. Limeira 901, Piracicaba, SP, CEP 13414-903, Brazil
| | - Marinês Nobre-Dos-Santos
- Department of Health Sciences and Pediatric Dentistry, Piracicaba Dental School, University of Campinas-UNICAMP, Av. Limeira 901, Piracicaba, SP, CEP 13414-903, Brazil.
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Thorn AK, Lin WS, Levon JA, Morton D, Eckert GJ, Lippert F. The effect of theobromine on the in vitro de- and remineralization of enamel carious lesions. J Dent 2020; 103S:100013. [PMID: 34059300 DOI: 10.1016/j.jjodo.2020.100013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 02/11/2020] [Accepted: 02/14/2020] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES This in vitro study investigated the effect of theobromine on the de- and remineralization of enamel carious lesions under plaque fluid-like conditions. METHODS Early carious lesions were created in 272 bovine enamel specimens and assigned to sixteen groups (n=17) based on Knoop surface microhardness (SMH). Lesions were demineralized again under plaque fluid-like conditions in the presence of fluoride (0.2 or 1ppm) and theobromine (0; 10; 100 or 200ppm) at different pH values (5.5 or 7.0) in a factorial design. SMH was determined again and percent SMH recovery (%SMHr) calculated. Three-way ANOVA was used for the fixed effects of fluoride, theobromine and pH levels to compare the differences between each level. RESULTS The three-way interaction was not significant (p=0.712). The two-way interaction between fluoride and pH was significant (p=0.030), whereas those between fluoride and theobromine as well as that for pH and theobromine were not (p=0.478 and p=0.998, respectively). Theobromine did not affect %SMHr at any of the tested concentrations. There were trends for the higher fluoride concentration and the higher pH resulting in more rehardening with the lesions exposed to 0.2ppm fluoride at pH 5.5 displaying significantly less rehardening than those exposed to 0.2ppm fluoride at pH of 7.0 and lesions exposed to 1ppm fluoride at pH of 5.5. CONCLUSION Theobromine, when continuously present in a plaque fluid-like medium at various concentrations and at different pH values, does not affect de- or remineralization of enamel carious lesions under the presently studied conditions. CLINICAL SIGNIFICANCE Based on the presently available evidence, theobromine cannot be recommended as an anticaries agent.
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Affiliation(s)
- Anna K Thorn
- Indiana University School of Dentistry, Department of Prosthodontics, 1121 W Michigan St., Indianapolis, IN, 46202, USA
| | - Wei-Shao Lin
- Indiana University School of Dentistry, Department of Prosthodontics, 1121 W Michigan St., Indianapolis, IN, 46202, USA
| | - John A Levon
- Indiana University School of Dentistry, Department of Prosthodontics, 1121 W Michigan St., Indianapolis, IN, 46202, USA
| | - Dean Morton
- Indiana University School of Dentistry, Department of Prosthodontics, 1121 W Michigan St., Indianapolis, IN, 46202, USA
| | - George J Eckert
- Indiana University School of Medicine, Department of Biostatistics, 410 W. Tenth St., Suite 3000, Indianapolis, IN, 46202, USA
| | - Frank Lippert
- Indiana University School of Dentistry, Department of Cariology, Operative Dentistry and Dental Public Health, 1121 W Michigan St., Indianapolis, IN, 46202, USA.
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Abstract
AbstractBackground: Dental caries disease is a dynamic process with a multi-factorial etiology. It is manifested by demineralization of enamel followed by damage spreading into the tooth inner structure. Successful early diagnosis could identify caries-risk and improve dental screening, providing a baseline for evaluating personalized dental treatment and prevention strategies. Methodology: Salivary proteome of the whole unstimulated saliva (WUS) samples was assessed in caries-free and caries-susceptible individuals of older adolescent age with permanent dentition using a nano-HPLC and MALDI-TOF/TOF mass spectrometry. Results: 554 proteins in the caries-free and 695 proteins in the caries-susceptible group were identified. Assessment using bioinformatics tools and Gene Ontology (GO) term enrichment analysis revealed qualitative differences between these two proteomes. Members of the caries-susceptible group exhibited a branch of cytokine binding gene products responsible for the regulation of immune and inflammatory responses to infections. Inspection of molecular functions and biological processes of caries-susceptible saliva samples revealed significant categories predominantly related to the activity of proteolytic peptidases, and the regulation of metabolic and catabolic processes of carbohydrates. Conclusions: Proteomic analysis of the whole saliva revealed information about potential risk factors associated with the development of caries-susceptibility and provides a better understanding of tooth protection mechanisms.
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Hassanali L, Wong FS, Lynch RJM, Anderson P. A Novel Kinetic Method to Measure Apparent Solubility Product of Bulk Human Enamel. Front Physiol 2017; 8:714. [PMID: 28983253 PMCID: PMC5613155 DOI: 10.3389/fphys.2017.00714] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 09/04/2017] [Indexed: 11/13/2022] Open
Abstract
Introduction: Tooth enamel mineral loss is influenced by its solubility product value, which is fundamental to the understanding of de- and remineralization resulting from a carious or erosive challenge. Published pKsp values for human enamel and hydroxyapatite range from 110 to 126 suggesting a heterogeneous nature of enamel solubility. However, this range of values may also result from the variety of methods used, e.g., some authors reporting values for suspensions of enamel powder and others for bulk enamel. The aim of this study was to develop a method to measure the solubility of bulk human enamel under controlled in vitro conditions simulating demineralization behavior of enamel within the oral environment using scanning microradiography (SMR). SMR was used to monitor real-time changes in enamel demineralization rates at increasing calcium concentrations in a caries simulating demineralization solution until the concentration at which thermodynamic equilibrium between enamel and solution was achieved. Method: 2 mm thick caries free erupted human enamel slabs with the natural buccal surfaces exposed were placed in SMR cells exposed to circulating caries-simulating 2.0 L 0.1 M pH = 4.0 acetic acid, at 25°C. SMR was used to continuously measure in real-time the decrease in mineral mass during the demineralization at 5 different points from on each slab. Demineralization rates were calculated from a linear regression curve of projected mineral mass against demineralization time. Changes in the demineralization rates were monitored following a series of successive increases in calcium (and phosphate at hydroxyapatite stoichiometric ratios of Ca:P 1.67) were added to the demineralizing solution, until demineralization ceased. The pH was maintained constant throughout. Results: Demineralization halted when the calcium concentration was ~30 mM. At higher calcium concentrations, mineral deposition (remineralization) occurred. By comparison with results from speciation software calculations for the calcium phosphate ternary system, this result suggests that the bulk solubility product of enamel (pKspBEnamel) under the conditions used is 121. Discussion: The apparent pKspBEnamel under these conditions was higher than many previous reported values, and much closer to those previously reported for HAp. However, this is a bulk value, and does not reflect that enamel is a heterogeneous material, nor the influence of ionic inclusions.
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Affiliation(s)
- Linda Hassanali
- Dental Physical Sciences Unit, Institute of Dentistry, Queen Mary University of LondonLondon, United Kingdom
| | - Ferranti S Wong
- Dental Physical Sciences Unit, Institute of Dentistry, Queen Mary University of LondonLondon, United Kingdom
| | - Richard J M Lynch
- Innovation Research and Development, Oral Healthcare, GlaxoSmithKlineWeybridge, United Kingdom
| | - Paul Anderson
- Dental Physical Sciences Unit, Institute of Dentistry, Queen Mary University of LondonLondon, United Kingdom
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Agnello M, Cen L, Tran NC, Shi W, McLean JS, He X. Arginine Improves pH Homeostasis via Metabolism and Microbiome Modulation. J Dent Res 2017; 96:924-930. [PMID: 28486080 DOI: 10.1177/0022034517707512] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Dental caries can be described as a dysbiosis of the oral microbial community, in which acidogenic, aciduric, and acid-adapted bacterial species promote a pathogenic environment, leading to demineralization. Alkali generation by oral microbes, specifically via arginine catabolic pathways, is an essential factor in maintaining plaque pH homeostasis. There is evidence that the use of arginine in dentifrices helps protect against caries. The aim of the current study was to investigate the mechanistic and ecological effect of arginine treatment on the oral microbiome and its regulation of pH dynamics, using an in vitro multispecies oral biofilm model that was previously shown to be highly reflective of the in vivo oral microbiome. Pooled saliva from 6 healthy subjects was used to generate overnight biofilms, reflecting early stages of biofilm maturation. First, we investigated the uptake of arginine by the cells of the biofilm as well as the metabolites generated. We next explored the effect of arginine on pH dynamics by pretreating biofilms with 75 mM arginine, followed by the addition of sucrose (15 mM) after 0, 6, 20, or 48 h. pH was measured at each time point and biofilms were collected for 16S sequencing and targeted arginine quantification, and supernatants were prepared for metabolomic analysis. Treatment with only sucrose led to a sustained pH drop from 7 to 4.5, while biofilms treated with sucrose after 6, 20, or 48 h of preincubation with arginine exhibited a recovery to higher pH. Arginine was detected within the cells of the biofilms, indicating active uptake, and arginine catabolites citrulline, ornithine, and putrescine were detected in supernatants, indicating active metabolism. Sequencing analysis revealed a shift in the microbial community structure in arginine-treated biofilms as well as increased species diversity. Overall, we show that arginine improved pH homeostasis through a remodeling of the oral microbial community.
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Affiliation(s)
- M Agnello
- 1 School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA
| | - L Cen
- 1 School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA
| | - N C Tran
- 1 School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA
| | - W Shi
- 1 School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA
| | - J S McLean
- 2 School of Dentistry, Department of Periodontics, University of Washington, Seattle, WA, USA
| | - X He
- 1 School of Dentistry, University of California at Los Angeles, Los Angeles, CA, USA
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Tenuta LMA, Del Bel Cury AA, Bortolin MC, Vogel GL, Cury JA. Ca, Pi, and F in the Fluid of Biofilm Formed under Sucrose. J Dent Res 2016; 85:834-8. [PMID: 16931867 DOI: 10.1177/154405910608500911] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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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11
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Nagata ME, Delbem ACB, Hall KB, Buzalaf MAR, Pessan JP. Fluoride and calcium concentrations in the biofilm fluid after use of fluoridated dentifrices supplemented with polyphosphate salts. Clin Oral Investig 2016; 21:831-837. [DOI: 10.1007/s00784-016-1838-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 04/24/2016] [Indexed: 11/28/2022]
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Jakubovics NS, Burgess JG. Extracellular DNA in oral microbial biofilms. Microbes Infect 2015; 17:531-7. [PMID: 25862975 DOI: 10.1016/j.micinf.2015.03.015] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Revised: 03/25/2015] [Accepted: 03/26/2015] [Indexed: 12/12/2022]
Abstract
The extracellular matrix of microbial biofilms is critical for surface adhesion and nutrient homeostasis. Evidence is accumulating that extracellular DNA plays a number of important roles in biofilm integrity and formation on hard and soft tissues in the oral cavity. Here, we summarise recent developments in the field and consider the potential of targeting DNA for oral biofilm control.
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Affiliation(s)
| | - J Grant Burgess
- School of Marine Science and Technology, Newcastle University, UK
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13
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Georgios A, Vassiliki T, Sotirios K. Acidogenicity and acidurance of dental plaque and saliva sediment from adults in relation to caries activity and chlorhexidine exposure. J Oral Microbiol 2015; 7:26197. [PMID: 25819399 PMCID: PMC4377323 DOI: 10.3402/jom.v7.26197] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 03/04/2015] [Accepted: 03/05/2015] [Indexed: 11/30/2022] Open
Abstract
Background The ecological plaque hypothesis for the etiopathogenesis of caries implies a microbial shift towards a more aciduric dental plaque microbiota, due to a frequent carbohydrate intake. Acid tolerance has been suggested as an important property of the caries-associated bacteria and several in vitro studies with mixed cultures indicated that a low pH rather than the carbohydrate availability is responsible for microbiota shifts associated with the development of dental caries. Objective To examine 1) the acidogenic potential (amount lactate produced per mg plaque and minute, at pH 7.0 or pH 5.5) and the aciduric potential (acidogenic potential at pH 5.5/acidogenic potential at pH 7.0) of dental plaque and salivary sediment taken from caries-active or caries-free adults, and 2) the effect of a short-term chlorhexidine treatment on these potentials. Design Dental plaque and saliva sediment samples were taken from caries-free and caries-active subjects and suspended in Ringer's solution containing 1% sucrose and buffered with 0.5 M 3-[N-morpholino]propanesulfonic acid (MOPS), pH 7.0, or 3-[N-morpholino]ethanesulfonic acid (MES), pH 5.5. After incubation at 37°C for 10–20 min, the concentration of lactic acid in the suspension was determined by an enzymatic assay. The acid production of dental plaque was also determined after a period of mouth rinsing with 0.2% chlorhexidine. Results Both dental plaque and salivary sediment from caries-free subjects exhibited significantly lower acidogenic potentials at both pHs compared to caries-active volunteers. The opposite was observed with the aciduric potential. Chlorhexidine treatment significantly reduced all three potentials but had no effect on the relative proportion of bacteria grown on acidic agar. Conclusions Caries-active adults have an oral microbiota characterised by an increased catabolic velocity for sugar. The increase is more pronounced at neutral than acidic pH. Exposure to chlorhexidine, through mouthwash, temporarily decreases the acidogenicity of the microbiota.
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Affiliation(s)
- Andreadis Georgios
- Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Topitsoglou Vassiliki
- Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Kalfas Sotirios
- Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece; ;
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14
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Liu C, Niu Y, Zhou X, Zhang K, Cheng L, Li M, Li Y, Wang R, Yang Y, Xu X. Hyperosmotic response of streptococcus mutans: from microscopic physiology to transcriptomic profile. BMC Microbiol 2013; 13:275. [PMID: 24289739 PMCID: PMC4219374 DOI: 10.1186/1471-2180-13-275] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 11/26/2013] [Indexed: 02/05/2023] Open
Abstract
BACKGROUND Oral streptococci metabolize carbohydrate to produce organic acids, which not only decrease the environmental pH, but also increase osmolality of dental plaque fluid due to tooth demineralization and consequent calcium and phosphate accumulation. Despite these unfavorable environmental changes, the bacteria continue to thrive. The aim of this study was to obtain a global view on strategies taken by Streptococcus mutans to deal with physiologically relevant elevated osmolality, and perseveres within a cariogenic dental plaque. RESULTS We investigated phenotypic change of S. mutans biofilm upon hyperosmotic challenge. We found that the hyperosmotic condition was able to initiate S. mutans biofilm dispersal by reducing both microbial content and extracellular polysaccharides matrix. We then used whole-genome microarray with quantitative RT-PCR validation to systemically investigate the underlying molecular machineries of this bacterium in response to the hyperosmotic stimuli. Among those identified 40 deferentially regulated genes, down-regulation of gtfB and comC were believed to be responsible for the observed biofilm dispersal. Further analysis of microarray data showed significant up-regulation of genes and pathways involved in carbohydrate metabolism. Specific genes involved in heat shock response and acid tolerance were also upregulated, indicating potential cross-talk between hyperosmotic and other environmental stress. CONCLUSIONS Hyperosmotic condition induces significant stress response on S. mutans at both phenotypic and transcriptomic levels. In the meantime, it may take full advantage of these environmental stimuli to better fit the fluctuating environments within oral cavity, and thus emerges as numeric-predominant bacterium under cariogenic conditions.
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Affiliation(s)
- Chengcheng Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Yulong Niu
- Key Lab of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Xuedong Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Keke Zhang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Lei Cheng
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Mingyun Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Yuqing Li
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Renke Wang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
| | - Yi Yang
- Key Lab of Bio-resources and Eco-environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, PR China
| | - Xin Xu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, PR China
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15
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Lynch RJ. The primary and mixed dentition, post-eruptive enamel maturation and dental caries: a review. Int Dent J 2013; 63 Suppl 2:25-30. [DOI: 10.1111/idj.12074] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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16
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Bradshaw DJ, Lynch RJ. Diet and the microbial aetiology of dental caries: new paradigms. Int Dent J 2013; 63 Suppl 2:39-47. [DOI: 10.1111/idj.12072] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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17
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Kunin AA, Belenova IA, Ippolitov YA, Moiseeva NS, Kunin DA. Predictive research methods of enamel and dentine for initial caries detection. EPMA J 2013; 4:19. [PMID: 23800183 PMCID: PMC3702480 DOI: 10.1186/1878-5085-4-19] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Accepted: 05/27/2013] [Indexed: 11/10/2022]
Abstract
Currently, various research methods of enamel and dentine for precautionary diagnostics of initial caries forms are developed; however, the vast majority of these do not provide objective criteria of caries diagnostics or are very difficult to perform. Therefore, the search of diagnostics and enamel research methods, which will allow predicting caries emergence and to carry out personalised prevention of this pathology, is necessary. In this review, modern diagnostic methods that allow understanding the main aspects of caries process, assess the risk of its development, and also suggest the possibility of emergency prevention of caries progression in the nearest future are presented.
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Affiliation(s)
- Anatoly A Kunin
- Therapeutic Dentistry Department, Faculty of Dentistry, Voronezh N,N, Burdenko State Medical Academy, Avenue of Revolution Str, 14, Voronezh, Russia.
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18
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Lippert F. The effects of lesion baseline characteristics and different Sr:Ca ratios in plaque fluid-like solutions on caries lesion de- and remineralization. Arch Oral Biol 2012; 57:1299-306. [DOI: 10.1016/j.archoralbio.2012.08.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Revised: 07/31/2012] [Accepted: 08/18/2012] [Indexed: 11/26/2022]
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19
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de Arruda AM, Santos PHD, Sundfeld RH, Berger SB, Briso ALF. Effect of Hydrogen Peroxide at 35% on the Morphology of Enamel and Interference in the De-remineralization Process: An In Situ Study. Oper Dent 2012; 37:518-25. [DOI: 10.2341/11-112-l] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
This study evaluated the microhardness and histomorphology of bovine enamel when 35% hydrogen peroxide is used. A total of 44 specimens were adapted to removable devices used by 11 individuals subjected to dental caries challenge. A decrease in microhardness was observed for all groups after the cariogenic challenge. Microscopic analysis revealed that fragments subjected to cariogenic challenge associated with bleaching had more intense superficial histologic changes, but the depth of the lesions remained unchanged. It was concluded that 35% hydrogen peroxide enhanced the reduction in hardness and histomorphologic changes in the enamel surface exposed to cariogenic challenge.
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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] [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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Qiqiang L, Huanxin M, Xuejun G. Longitudinal study of volatile fatty acids in the gingival crevicular fluid of patients with periodontitis before and after nonsurgical therapy. J Periodontal Res 2012; 47:740-9. [DOI: 10.1111/j.1600-0765.2012.01489.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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22
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Lynch R, Churchley D, Butler A, Kearns S, Thomas G, Badrock T, Cooper L, Higham S. Effects of Zinc and Fluoride on the Remineralisation of Artificial Carious Lesions under Simulated Plaque Fluid Conditions. Caries Res 2011; 45:313-22. [DOI: 10.1159/000324804] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2010] [Accepted: 01/27/2011] [Indexed: 11/19/2022] Open
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23
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Lippert F, Butler A, Lynch R. Enamel Demineralization and Remineralization under Plaque Fluid-Like Conditions: A Quantitative Light-Induced Fluorescence Study. Caries Res 2011; 45:155-61. [DOI: 10.1159/000325743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 02/16/2011] [Indexed: 11/19/2022] Open
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24
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Lynch RJM, Mony U, ten Cate JM. Effect of Lesion Characteristics and Mineralising Solution Type on Enamel Remineralisation in vitro. Caries Res 2007; 41:257-62. [PMID: 17556834 DOI: 10.1159/000101914] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2006] [Accepted: 01/17/2007] [Indexed: 11/19/2022] Open
Abstract
The aim was to study the effect of lesion preparation technique and solution composition on remineralization of artificial lesions in vitro. Lesions were prepared with similar total mineral loss, but different mineral distribution, i.e., low (14.0) or high R (34.8) values. Lesions from both groups were remineralized (10 days, 37 degrees C) in two different solutions, with similar supersaturation with respect to hydroxyapatite (St), but calcium:phosphate ratios representing either hydroxyapatite stoichiometry or plaque fluid (PF). Remineralization was quantified microradiographically, mineral distribution was compared with natural white-spot lesions. Mineral loss and depth decreased significantly, and surface-zone mineral content (Zmax) increased significantly, in all lesions. Overall there was a significant relationship of decreasing remineralization with increasing Zmax, but not within either lesion type. PF was significantly more efficient than St in high-R lesions, with lesions remineralizing almost completely in PF. Remineralization was not significantly different in PF or St for low-R lesions but in high-R lesions, PF was more efficient than St, possibly through differences in relative saturations with respect to different calcium phosphates. Differences in area:solution ratios and baseline Zmax values may also have explained the different response to PF. Low-R lesions were similar to natural white-spot lesions in terms of mineral distribution, whereas high-R were not. Concluding, both lesion and remineralizing solution type had a marked influence on remineralization. It is proposed that use of low-R lesions would be more appropriate where more physiologically relevant mineral distribution is required, whereas high-R lesions would be appropriate for studying inherent remineralizing efficiency.
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25
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Yamazaki H, Litman A, Margolis HC. Effect of fluoride on artificial caries lesion progression and repair in human enamel: regulation of mineral deposition and dissolution under in vivo-like conditions. Arch Oral Biol 2006; 52:110-20. [PMID: 17049334 PMCID: PMC2040327 DOI: 10.1016/j.archoralbio.2006.08.012] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2006] [Revised: 06/27/2006] [Accepted: 08/23/2006] [Indexed: 11/18/2022]
Abstract
OBJECTIVE This study was carried out to determine in vitro the effect of fluoride on (1) the demineralization of sound human enamel and (2) the progression of artificial caries-like lesions, under relevant oral conditions. METHODS Thin sections of sound human enamel were exposed to solutions undersaturated with respect to tooth enamel to a degree similar to that found in dental plaque fluid following sucrose exposure in vivo, containing fluoride concentrations (0-0.38ppm) found in plaque fluid. Mineral changes were monitored for 98 days, using quantitative microradiography. The effect of fluoride (1.0-25.0ppm) on the progression of artificial caries-like lesions was similarly studied. RESULTS Fluoride concentrations of 0.19ppm and greater were found to prevent the demineralization of sound enamel in vitro. However, significantly higher concentrations of fluoride (25.0ppm) were required to prevent further demineralization of artificial caries-like lesions. Demineralizing solutions with intermediate fluoride concentrations (2.1-10.1ppm) induced simultaneously remineralization in the outer portion of the lesion and demineralization in the inner portion. Simultaneous remineralization and demineralization were also observed in hydroxyapatite pellets. CONCLUSIONS Our results show that the observed effect of fluoride on enamel demineralization is not solely a function of bulk solution properties, but also depends on the caries-status of the enamel surface. A mechanistic model presented indicates that, in comparison to sound enamel surfaces, higher concentrations of fluoride are required to prevent the progression of artificial caries-like lesions under in vivo-like conditions since the diffusion of mineral ions that promote remineralization is rate-limiting.
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Affiliation(s)
- Hajime Yamazaki
- Health Care Products Research Laboratories, Kao Corporation, 1–3, Bunka 2 chome, Sumidaku, Tokyo 131‐8501, Japan
| | - Amy Litman
- Department of Biomineralization, The Forsyth Institute, 140 The Fenway, Boston Massachusetts 02115, USA, , phone: +1‐617‐892‐8346, fax: +1‐617‐892‐8432
| | - Henry C. Margolis
- Department of Biomineralization, The Forsyth Institute, 140 The Fenway, Boston Massachusetts 02115, USA, , phone: +1‐617‐892‐8346, fax: +1‐617‐892‐8432
- Correspondence to: Henry C. Margolis
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26
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Leme AP, Koo H, Bellato C, Bedi G, Cury J. The role of sucrose in cariogenic dental biofilm formation--new insight. J Dent Res 2006; 85:878-87. [PMID: 16998125 PMCID: PMC2257872 DOI: 10.1177/154405910608501002] [Citation(s) in RCA: 351] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Dental caries is a biofilm-dependent oral disease, and fermentable dietary carbohydrates are the key environmental factors involved in its initiation and development. However, among the carbohydrates, sucrose is considered the most cariogenic, because, in addition to being fermented by oral bacteria, it is a substrate for the synthesis of extracellular (EPS) and intracellular (IPS) polysaccharides. Therefore, while the low pH environment triggers the shift of the resident plaque microflora to a more cariogenic one, EPS promote changes in the composition of the biofilms' matrix. Furthermore, it has recently been shown that the biofilm formed in the presence of sucrose presents low concentrations of Ca, P(i), and F, which are critical ions involved in de- and remineralization of enamel and dentin in the oral environment. Thus, the aim of this review is to explore the broad role of sucrose in the cariogenicity of biofilms, and to present a new insight into its influence on the pathogenesis of dental caries.
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Affiliation(s)
- A.F. Paes Leme
- Faculty of Dentistry of Piracicaba, UNICAMP, Av. Limeira, 901, CEP 13414-903, Piracicaba, SP, Brazil
| | - H. Koo
- University of Rochester Medical Center, Rochester, NY, USA
| | - C.M. Bellato
- Center for Nuclear Energy in Agriculture, University of São Paulo-CENA/USP
| | - G. Bedi
- University of Rochester Medical Center, Rochester, NY, USA
| | - J.A. Cury
- Faculty of Dentistry of Piracicaba, UNICAMP, Av. Limeira, 901, CEP 13414-903, Piracicaba, SP, Brazil
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27
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Arnold WH, Forer S, Heesen J, Yudovich K, Steinberg D, Gaengler P. The in vitro effect of fluoridated milk in a bacterial biofilm--enamel model. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub 2006; 150:63-9. [PMID: 16936902 DOI: 10.5507/bp.2006.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES The purpose of this study was to investigate the effect of milk and fluoridated milk on bacterially induced caries-like lesions. SAMPLE AND METHODS Extracted impacted human molars were cut in half and covered with a varnish leaving a 4*4 mm window. The samples were coated with biofilm of S. sobrinus and were further divided into three experimental groups of S. sobrinus, S. sobrinus and milk and S. sobrinus and fluoridated milk. As negative controls served teeth incubated in saline. Of twenty tooth halves serial ground sections were cut through the lesions and investigated with polarization light microscopy (PLM) and scanning electron microscopy (SEM) and EDX element analysis. The PLM photographs were used for 3D reconstruction, volumetric assessment and determination of the extension of the lesion zones. Of eight tooth halves the biofilm on the enamel surface was studied with SEM and EDX element analysis. RESULTS Volumetric assessment showed a statistically significant difference in the volume of the body of the lesion and the translucent zone between the milk group and fluoridated milk group. Quantitative element analysis demonstrated significant differences between sound enamel and the superficial layer in the fluoridated milk group. The biofilm on the enamel surface showed an increased Ca content in the milk group and fluoridated milk group. CONCLUSIONS Milk as a common nutrient seems to play a complex role in in-vitro biofilm--enamel interactions stimulating bacterial demineralization on one hand, and, as effective fluoride carrier, inhibits caries-like demineralization.
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Affiliation(s)
- Wolfgang H Arnold
- Department of Anatomy, Faculty of Dental Medicine, University of Witten, Herdecke, Germany.
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28
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Abstract
The hyperosmotic stress response of Streptococcus mutans was investigated. Real-time reverse transcriptase-PCR and slot-blot analysis revealed that opuAA, opcA, Smu.2115, sodA and nox were induced after exposure to 0.4 M NaCl. Our data suggest that there is a cross-talk between osmotic and oxidative stress responses in S. mutans. Inactivation of Smu.2115, encoding a putative oxidoreductase, resulted in an acid-resistant and hydrogen peroxide-sensitive phenotype.
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Affiliation(s)
- Jacqueline Abranches
- Department of Oral Biology, University of Florida College of Dentistry, Gainesville, FL 32610, USA
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29
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Delgado-Angulo EK, Prado-Armas J, Bernabé E. First molar eruption related to plaque acidogenicity in children of different socio-economic status. Acta Odontol Scand 2006; 64:134-40. [PMID: 16809189 DOI: 10.1080/00016350500419990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
OBJECTIVE The aim of this study was to evaluate the association between the eruption stage of the lower first permanent molar and dental plaque acidogenicity. Socio-economic status (SES), gender, and oral hygiene condition were also variables considered. MATERIAL AND METHODS 230 children between 6 and 8 years of age were recruited from one public and one private primary school with different SES in Lima, Peru. Clinical examinations were performed to assess lower first permanent molar eruption stage, plaque acidogenicity, and oral hygiene condition. Bivariate associations were analyzed through chi-square tests and the variable interactions were analyzed through a hierarchical log-linear analysis with backward elimination. RESULTS 21.8% of the population had highly acidogenic plaque, 34.3% acidogenic plaque, and 43.9% non-acidogenic plaque. Of the lower first permanent molars, 46.1% were fully erupted, whereas 53.9% were partially erupted. According to the final log-linear model, children with fully erupted molars and non-acidogenic plaque are less frequent in low than in high SES. Also, the frequency of children with partially erupted molars and acidogenic to highly acidogenic plaque is higher in males than in females. Finally, fully erupted molars and non-acidogenic plaque are more frequent in children with good hygiene than in children with moderate to poor hygiene. CONCLUSIONS Association between eruption stage of the lower first permanent molar and plaque acidogenicity was not significant in a bivariate context. However, in a multivariate context, socio-economic status, oral hygiene condition, and gender had an impact on the association between the two main variables.
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Affiliation(s)
- Elsa K Delgado-Angulo
- Department of Dentistry of the Child and Adolescent, Universidad Peruana Cayetano Heredia, Lima, Peru
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30
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Lynch RJM, Mony U, Ten Cate JM. The Effect of Fluoride at Plaque Fluid Concentrations on Enamel De- and Remineralisation at Low pH. Caries Res 2006; 40:522-9. [PMID: 17063024 DOI: 10.1159/000095652] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2005] [Accepted: 09/26/2005] [Indexed: 11/19/2022] Open
Abstract
The aim was to study the effect of fluoride, at concentrations typical of plaque fluid, on de- and remineralisation of subsurface lesions at low pH. Artificial lesions in human enamel were microradiographed to quantify mineral loss and placed in acid-gel systems at pH 4.8, 5.0 and 5.2. Calcium and phosphate were added to give initial Ca and Pi concentrations of either 4.1 and 8.0 mM, or 4.7 and 9.7 mM, at each pH value. Further, at each pH and combination of Ca and Pi, fluoride was added to the gels to give initial concentrations of 1, 2 or 5 ppm, with a non-fluoride control group. The lesions were removed after 10 days and change in mineral content quantified. Those in the non-fluoride control groups had demineralised further. Those exposed to fluoride had remineralised, the amount increasing with increasing fluoride concentration, up to a maximum value of approximately 75%. Calcium activity in the gels was reduced significantly, to levels similar to those reported for plaque fluid at low pH. Fluoride activity was also reduced, though to a lesser extent. These findings contrast with those from studies which have simulated conditions on smooth surface sites and which used experimental solutions composed to reflect salivary fluoride concentrations, where net demineralisation was observed at low pH. This reflects the need for further study of de- and remineralisation under plaque-fluid conditions. In conclusion, subsurface lesions were remineralised at low pH by fluoride at concentrations found in plaque fluid during a cariogenic challenge.
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Affiliation(s)
- R J M Lynch
- Unilever Oral Care, Bebington, Wirral, UK. richard.lynch.unilever.com
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31
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Abstract
AIM To summarise clinical support for the anti-caries efficacy of fluoride toothpastes containing sodium monofluorophosphate (SMFP) and to discuss the possible means by which the abrasive particles in calcium carbonate-based SMFP toothpastes might complement and/or enhance fluoride efficacy. BACKGROUND The anti-caries efficacy of fluoride has been proven beyond any reasonable doubt, and the efficacy of SMFP, when incorporated into a variety of compatible toothpaste formulations, has been established in numerous clinical trials. Calcium carbonate-based toothpastes may also influence caries by effecting an increase in plaque calcium levels; an inverse relationship between plaque calcium and caries is well-established. It has also been reported that plaque fluoride levels are dependent on plaque calcium levels. Hence elevated plaque calcium resulting from the use of calcium carbonate-based toothpastes has the potential to elevate plaque fluoride, itself linked to reduced caries experience. It has been shown that calcium carbonate particles are retained by plaque and this may also influence caries by neutralising harmful plaque acids and concurrently liberating calcium. CONCLUSION Fluoride delivered from calcium carbonate-based SMFP toothpastes is an effective means of reducing caries. Further, calcium carbonate may confer additional benefits through elevation of oral calcium levels and neutralisation of plaque-acids.
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Abstract
AIM To review studies in the dental literature regarding the anti-caries mode of action of glycerophosphate with special reference to calcium glycerophosphate. The cariostatic properties of calcium glycerophosphate have been demonstrated during numerous in vivo and in vitro studies. Several mechanisms have been suggested and these include plaque-pH buffering, elevation of plaque calcium and phosphate levels and direct interaction with dental mineral. There is credible evidence that calcium glycerophosphate has the potential to reduce the progression of caries via all of these mechanisms if it is applied frequently and at a sufficiently high concentration. Reduction of plaque mass has also been proposed as a cariostatic mechanism but this seems less likely. Animal studies have shown that the calcium glycerophosphate/sodium monofluorophosphate system can have a greater anti-caries effect than sodium monofluorophosphate alone and this was subsequently confirmed in a caries clinical trial. We conclude that elevation of calcium levels in plaque is the most likely explanation and that any means of enhancing this effect has significant promise as a means to further increase in anti-caries potential of the calcium glycerophosphate/sodium monofluorophosphate system compared to sodium monofluorophosphate alone.
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Abstract
Dental research over the last century has advanced our understanding of the etiology and pathogenesis of caries lesions. Increasing knowledge of the dynamic demineralization/remineralization processes has led to the current consensus that bacteria-mediated tooth destruction can be arrested or even to some degree reversed by adopting fluoride and other preventive measures without using restorative materials. Our experimental approach provided new insight into the stoichiometries and solubility properties of human enamel and dentin mineral. The determination of the solubility product constant on the basis of the stoichiometric model (Ca)5.x(Mg)q(Na)u(HPO4)v(CO3)w(PO4)3.y(OH,F)1.z, verifies the difference in their solubility properties, supporting the phase transformation between tooth mineral and calcium phosphates in a wide range of fluid compositions as found in the oral environment. Further refinement of the stoichiometry and solubility parameters is essential to assess quantitatively the driving force for de- and remineralization of enamel and dentin in the oral fluid environment. Prediction of the effects of a combination of inhibitors and accelerator(s) on remineralization kinetics is also required. In order to develop devices efficient for optimizing remineralization in the lesion body, it is a critical question how, and to what extent, fluoride can compensate for the activity of any inhibitors in the mineralizing media.
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Affiliation(s)
- T Aoba
- Department of Pathology, The Nippon Dental University, Tokyo, Japan.
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34
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Zaura E, Buijs MJ, ten Cate JM. The effects of the solubility of artificial fissures on plaque pH. J Dent Res 2002; 81:567-71. [PMID: 12147749 DOI: 10.1177/154405910208100813] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Dissolution of the fissure walls may buffer acids formed in plaque and thus prevent the penetration of acids into the fissure. To test this, five volunteers wore dentin, enamel, and polyacrylate specimens with narrow grooves for 7 days to accumulate plaque. Temporal (pre- and post-glucose) and spatial (0-0.7 mm) pH profiles were recorded in the grooves in a flow-through reactor with pH microsensors. Mineral loss was assessed by transverse microradiography. We observed that resting pH did not differ among substrata. The median pH 1 hr post-glucose at the bottoms of dentin, enamel, and polyacrylate grooves was 6.7, 6.2, and 5.7, respectively (p < 0.01). On subject level, lesions formed in dentin correlated with pH changes in polyacrylate, where no buffering of acids due to mineral dissolution occurred. We conclude that fluoride-deficient tissue at the bottom of a fissure is at increased risk for caries, if acids are not buffered near the entrance to the fissure.
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Affiliation(s)
- E Zaura
- Department of Cariology, Endodontology, Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Louwesweg 1, NL-1066 EA Amsterdam, The Netherlands.
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