An in vitro microbial model associated with sucrose to produce dentin caries lesions

AbstractThe complexity of the oral environment and ethical issues have prompted the development of an in vitro bacterial model to evaluate the effect of frequency of sucrose exposure on dentin caries formation, biofilm composition, and pH changes. In the experiment, dentin specimens (n=45) were randomly divided into four groups: control (C), negative control (0S), 3S (three sucrose baths), and 6S (six sucrose baths). The specimens then were inoculated with Streptococcus mutans and treated according to the protocol described below. Dentin demineralization and lesion depth were assessed by transverse microradiography. Extracellular polysaccharides that formed in the biofilm were analyzed and counts of microorganisms in the carious dentin were measured. After a 7-day period of growth, the biofilm pH was assessed before and after sucrose baths (n=5). The addition of sucrose led to dentin caries development regardless of the number of sucrose baths performed. The number of colony forming units (cfu) from the carious dentin did not differ among the treatment groups, though the extracellular polysaccharides from both 3S and 6S differed from 0S. The pH decreased immediately after the sucrose bath but increased again after 5 min. We demonstrate here that the in vitro microbial model for the study of dentin caries formation is reproducible and able to produce dentin caries, irrespective of the frequency of sucrose exposure.

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Protective effect of titanium tetrafluoride and silver diamine fluoride on radiation-induced dentin caries in vitro

Scientific Reports ◽

10.1038/s41598-021-85748-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Beatriz Martines de Souza ◽

Mayara Souza Silva ◽

Aline Silva Braga ◽

Patrícia Sanches Kerges Bueno ◽

Paulo Sergio da Silva Santos ◽

...

Keyword(s):

Lactic Acid ◽

Protective Effect ◽

Acid Production ◽

Lactic Acid Production ◽

Negative Control ◽

Titanium Tetrafluoride ◽

Silver Diamine Fluoride ◽

Dentin Caries ◽

Radiation Induced

AbstractThis in vitro study evaluated the protective effect of titanium tetrafluoride (TiF4) varnish and silver diamine fluoride (SDF) solution on the radiation-induced dentin caries. Bovine root dentin samples were irradiated (70 Gy) and treated as follows: (6 h): 4% TiF4 varnish; 5.42% NaF varnish; 30% SDF solution; placebo varnish; or untreated (negative control). Microcosm biofilm was produced from human dental biofilm (from patients with head-neck cancer) mixed with McBain saliva for the first 8 h. After 16 h and from day 2 to day 5, McBain saliva (0.2% sucrose) was replaced daily (37 °C, 5% CO2) (biological triplicate). Demineralization was quantified by transverse microradiography (TMR), while biofilm was analyzed by using viability, colony-forming units (CFU) counting and lactic acid production assays. The data were statistically analyzed by ANOVA (p < 0.05). TiF4 and SDF were able to reduce mineral loss compared to placebo and the negative control. TiF4 and SDF significantly reduced the biofilm viability compared to negative control. TiF4 significantly reduced the CFU count of total microorganism, while only SDF affected total streptococci and mutans streptococci counts. The varnishes induced a reduction in lactic acid production compared to the negative control. TiF4 and SDF may be good alternatives to control the development of radiation-induced dentin caries.

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Demineralization Inhibitory Effects of Highly Concentrated Fluoride Dentifrice and Fluoride Gels/Solutions on Sound Dentin and Artificial Dentin Caries Lesions in vitro

Caries Research ◽

10.1159/000509931 ◽

2020 ◽

pp. 1-14

Author(s):

Daniel Erdwey ◽

Hendrik Meyer-Lueckel ◽

Marcella Esteves-Oliveira ◽

Christian Apel ◽

Richard Johannes Wierichs

Keyword(s):

In Vitro Study ◽

Inhibitory Effect ◽

Negative Effects ◽

Dentin Caries ◽

Before And After ◽

Amine Fluoride ◽

Ph Cycling ◽

Fluoride Dentifrice ◽

Caries Lesions

Objectives: The aim of this in vitro study was to compare the demineralization inhibitory effect of gels/solutions used in combination with either standard or highly fluoridated dentifrices on sound dentin as well as on artificial dentin caries-like lesions. Methods: Bovine dentin specimens (n = 240) with two different surfaces each (sound [ST] and artificial caries lesion [DT]) were prepared and randomly allocated to twelve groups. Weekly interventions during pH-cycling (28 days, 6 × 120 min demineralization/day) were: the application of gels/solutions containing amine fluoride/sodium fluoride (12,500 ppm F [ppm]; pH = 4.4; AmF); NaF (12,500 ppm; pH = 6.6; NaF1); NaF (12,500 ppm; pH = 6.3; NaF2); silver diamine fluoride (14,200 ppm; pH = 8.7; SDF); acidulated phosphate fluoride (12,500 ppm; pH = 3.8; APF), and no intervention (standard control; S). Furthermore, half of the specimens in each group were brushed (10 s; twice per day) with dentifrice slurries containing either 1,450 ppm (e.g., AmF1450) or 5,000 ppm (e.g., AmF5000). Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after pH-cycling using transversal microradiography. Results: After pH-cycling Ss showed significantly increased ΔZDT and LDDT values, indicating further demineralization. In contrast, except for one, all groups including fluoride gels/solutions showed significantly decreased ΔZDT values. Additional use of most fluoride gels/solutions significantly enhanced mineral gain, mainly in the surface area; however, acidic gels/solutions seemed to have negative effects on lesion depths. Significance: Under the present pH-cycling conditions the highly fluoridated dentifrice significantly reduced caries progression and additional application of nearly all of the fluoride gels/solutions resulted in remineralization. However, there was no difference in the remineralizing capacity of fluoride gels/solutions when used in combination with either standard or highly fluoridated dentifrices.

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Re- and Demineralization Characteristics of Enamel Depending on Baseline Mineral Loss and Lesion Depth in situ

Caries Research ◽

10.1159/000444537 ◽

2016 ◽

Vol 50 (2) ◽

pp. 141-150 ◽

Cited By ~ 10

Author(s):

Richard J. Wierichs ◽

Julian Lausch ◽

Hendrik Meyer-Lueckel ◽

Marcella Esteves-Oliveira

Keyword(s):

Negative Control ◽

Pronounced Change ◽

Protocol Violation ◽

Lesion Depth ◽

Treatment Groups ◽

Before And After ◽

Double Blinded ◽

Bovine Enamel ◽

Mineral Loss

Objectives: The aim of this double-blinded, randomized, cross-over in situ study was to evaluate the re- and demineralization characteristics of sound enamel as well as lowly and highly demineralized caries-like enamel lesions after the application of different fluoride compounds. Methods: In each of three experimental legs of 4 weeks, 21 participants wore intraoral mandibular appliances containing 4 bovine enamel specimens (2 lowly and 2 highly demineralized). Each specimen included one sound enamel and either one lowly demineralized (7 days, pH 4.95) or one highly demineralized (21 days, pH 4.95) lesion, and was positioned 1 mm below the acrylic under a plastic mesh. The three randomly allocated treatments (application only) included the following dentifrices: (1) 1,100 ppm F as NaF, (2) 1,100 ppm F as SnF2 and (3) 0 ppm F (fluoride-free) as negative control. Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after the in situ period using transversal microradiography. Results: Of the 21 participants, 6 did not complete the study and 2 were excluded due to protocol violation. Irrespectively of the treatment, higher baseline mineral loss and lesion depth led to a less pronounced change in mineral loss and lesion depth. Except for ΔΔZ of the dentifrice with 0 ppm F, sound surfaces showed significantly higher ΔΔZ and ΔLD values compared with lowly and highly demineralized lesions (p < 0.05, t test). Conclusion: Re- and demineralization characteristics of enamel depended directly on baseline mineral loss and lesion depth. Treatment groups should therefore be well balanced with respect to baseline mineral loss and lesion depth.

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Probiotic Effects on Multispecies Biofilm Composition, Architecture, and Caries Activity In Vitro

Microorganisms ◽

10.3390/microorganisms8091272 ◽

2020 ◽

Vol 8 (9) ◽

pp. 1272

Author(s):

Zhihui Chen ◽

Sebastian Schlafer ◽

Gerd Göstemeyer ◽

Falk Schwendicke

Keyword(s):

Lactobacillus Reuteri ◽

Quantitative Polymerase Chain Reaction ◽

Lactobacillus Rhamnosus ◽

Negative Control ◽

Caries Activity ◽

Actinomyces Naeslundii ◽

Colony Forming Units ◽

Bovine Enamel ◽

Culture Supernatants

While probiotics have been tested for their anti-caries effect in vitro and also clinically, there is a lack of understanding of their effects on complex dental biofilms. We assessed two probiotics, Lactobacillus reuteri and Streptococcus oligofermentans, on a continuous-cultured model containing Streptococcus mutans, Lactobacillus rhamnosus and Actinomyces naeslundii. Cariogenic biofilms were grown on bovine enamel specimens and daily challenged with L. reuteri or S. oligofermentans whole culture (LC/SC) or cell-free supernatant (LS/SS) or medium only (negative control, NC) (n = 21/group) for 10 days. Biofilm was assessed via counting colony-forming units, quantitative polymerase chain reaction, and fluorescence in situ hybridization. Caries activity was determined by pH measurements and by assessing mineral loss (ΔZ) using transverse microradiography. Both LC and SC significantly reduced total and strain-specific cariogenic bacterial numbers (p < 0.05). ΔZ was reduced in LC (mean ± SD: 1846.67 ± 317.89) and SC (3315.87 ± 617.30) compared to NC (4681.48 ± 495.18, p < 0.05). No significant reductions in bacterial numbers and ΔZ was induced by supernatants. Biofilm architecture was not considerably affected by probiotic applications. Viable probiotics L. reuteri and S. oligofermentans, but not their culture supernatants, could reduce the caries activity of multi-species biofilms in vitro.

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Effects of a mixture of organisms,Lactobacillus acidophilusorStreptococcus faecalison cholesterol metabolism in rats fed on a fat- and cholesterol-enriched diet

British Journal Of Nutrition ◽

10.1079/bjn19960092 ◽

1996 ◽

Vol 76 (6) ◽

pp. 857-867 ◽

Cited By ~ 62

Author(s):

Michihiro Fukushima ◽

Masuo Nakano

Keyword(s):

Rice Bran ◽

Cholesterol Metabolism ◽

Micelle Formation ◽

The Other ◽

Cholesterol Concentration ◽

Control Group ◽

Treatment Groups ◽

Colony Forming Units ◽

Organism Group

The effect of a mixture of organisms (a probiotic mixture) comprisingBacillus, Lactobacillus, Streptococcus, Clostridium, SaccharomycesandCandida(107–8colony-forming units/g rice bran of each component) on lipid metabolism was compared with that ofL. acidophilusand that ofS. faecalis. There were four treatment groups: rice bran (control), the mixture of organisms,L. acihphifusorS. faecds(30g/kg) were given to rats in a fat- and cholesterol-enriched diet for 4 weeks. The serum total cholesterol concentration of the group fed on the mixture of organisms was reduced by 15–33% compared with the other groups at the end of the 4week feeding period (P< 0·05). This group also had a lower hepatic cholesterol concentration (36–44%) than the two single-bacteria groups (P< 0·05). 3-Hydmxy-3-methylglutaryl-Co A reductase (NADPH; EC 1.1.1.34) activities of the mixed-organism andL. acidophifusgroups were significantly lower (61–63%) than those of the other groups (P< 0·05); the activity of the S. faecalis group was also signikantly lower (42%) than that of the control group (P< 0·05). The faecal cholesterol and bile acid concentrations of the mixed-organism group increased compared with those of theL. acidophilusandS. faecalisgroups (P< 0·05). The capacity of the mixed- organism cells to bind bile saltin vitrowas significantly higher (approximately 50%) than that of the singlebacteria cells (P< 0·05). On the other hand, cholesterol micelle formation for the mixed-organism cells was significantly (approximately 9%) lower than that of the singlebacteria cells (P< 0·05). These results indicate that the mixture of organisms decreased the synthesis of cholesterol in the liver and increased the loss of steroids from the intestine, in rats. Thus, the mixture of organisms had a hypocholeaterolaemic role

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Análise da eficácia de dentifrícios clareadores e seus efeitos na superfície dental: um estudo in vitro

Revista da Faculdade de Odontologia de Porto Alegre ◽

10.22456/2177-0018.108159 ◽

2021 ◽

Vol 62 (1) ◽

pp. 22-32

Author(s):

Eduardo Monteiro Toschi ◽

Eliseu Aldrighi Münchow ◽

Luísa Weber Mercado ◽

Rafael Melara ◽

Sandra Liana Henz

Keyword(s):

Surface Roughness ◽

Color Change ◽

Negative Control ◽

Tooth Whitening ◽

Over The Counter ◽

Dental Office ◽

Color System ◽

Before And After ◽

Bovine Enamel

Tooth whitening can be performed at the dental office, at-home or upon the use of OTC (Over-the-Counter) products. Among the latter, there are whitening toothpastes that promise to bleach and to prevent tooth staining. Objectives: (1) to investigate the bleaching and abrasive potential of different whitening dentifrices to enamel; and (2) to evaluate the effect of Oral-B 3D White Perfection® (Oral-B) toothpaste in preventing staining. Materials and Methods: Bovine enamel samples were stained and brushed for 14 days with water (negative control) or with different products: Colgate Total 12® (control), Oral-B, Sensodyne Branqueador Extra Fresh® (Sensodyne), and Colgate Luminous White Advanced® (Colgate). Oral-B was also tested before and after staining. The samples were tested by their color (spectrophotometer) and surface roughness (profilometer). Color change (ΔDE00) was calculated using the CIEDE2000 color system. The data were analyzed using Kruskal-Wallis, SNK, and Mann-Whitney tests (ɑ=5%). Results: The negative control showed the lowest ΔE00 (p

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Impact of Grain Sorghum Polyphenols on Microbiota of Normal Weight and Overweight/Obese Subjects during In Vitro Fecal Fermentation

Nutrients ◽

10.3390/nu11020217 ◽

2019 ◽

Vol 11 (2) ◽

pp. 217 ◽

Cited By ~ 7

Author(s):

Danielle Ashley ◽

Daya Marasini ◽

Cindi Brownmiller ◽

Jung Lee ◽

Franck Carbonero ◽

...

Keyword(s):

Gut Microbiota ◽

Batch Fermentation ◽

Short Chain Fatty Acids ◽

Negative Control ◽

Normal Weight ◽

Weight Class ◽

Gut Health ◽

Sorghum Bran ◽

Before And After

The human gut microbiota is considered as a crucial mediator between diet and gut homeostasis and body weight. The unique polyphenolic profile of sorghum bran may promote gastrointestinal health by modulating the microbiota. This study evaluated gut microbiota and modulation of short-chain fatty acids (SCFA) by sorghum bran polyphenols in in vitro batch fermentation derived from normal weight (NW, n = 11) and overweight/obese (OO, n = 11) subjects’ fecal samples. Six separate treatments were applied on each batch fermentation: negative control (NC), fructooligosaccharides (FOS), black sorghum bran extract (BSE), sumac sorghum bran extract (SSE), FOS + BSE, or FOS + SSE; and samples were collected before and after 24 h. No significant differences in total and individual SCFA production were observed between NW and OO subjects. Differential responses to treatment according to weight class were observed in both phyla and genera. Sorghum bran polyphenols worked with FOS to enhance Bifidobacterium and Lactobacillus, and independently stimulated Roseburia and Prevotella (p < 0.05). Our results indicate that sorghum bran polyphenols have differential effects on gut health and may positively impact gut ecology, with responses varying depending on weight class.

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Comparative in vitro study of root roughness after instrumentation with ultrasonic and diamond tip sonic scaler

Journal of Applied Oral Science ◽

10.1590/s1678-77572006000200011 ◽

2006 ◽

Vol 14 (2) ◽

pp. 124-129 ◽

Cited By ~ 10

Author(s):

Fernanda Vieira Ribeiro ◽

Renato Correa Viana Casarin ◽

Francisco Humberto Nociti Júnior ◽

Enilson Antônio Sallum ◽

Antonio Wilson Sallum ◽

...

Keyword(s):

Surface Roughness ◽

In Vitro Study ◽

Root Surface ◽

Control Group ◽

Human Teeth ◽

Treatment Groups ◽

Before And After ◽

Root Surfaces ◽

Scanning Electron

OBJECTIVE: The purpose of this study was to evaluate the root surface roughness after instrumentation with hand curette and diamond-coated sonic and universal ultrasonic tips. MATERIALS AND METHODS: Forty root surfaces of human teeth were randomly assigned to four treatment groups: control group (without instrumentation), curette instrumentation, ultrasonic instrumentation with universal tip and sonic instrumentation with diamond-coated tip. Each sample was instrumented with fifteen strokes. Before and after instrumentation, surface roughness was measured. In addition, the root surface topography was examined after treatment under the scanning electron microscope. RESULTS: Significant statistical differences (p <0.05) were observed when comparing the control group (0.48±0.07mm) to the treated groups (hand - 1.246±0.279mm, ultrasonic - 1.468±0.177mm and sonic instrumentation - 1.576±0.20mm). The highest roughness was produced by diamond-coated sonic tip and by ultrasonic universal tip (p >0.05). CONCLUSION: The diamond-coated tip with sonic scaler instrumentation and ultrasonic instrumentation produce similar root surface roughness, higher than curette instrumentation.

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β2-Adrenoceptor desensitization in human alveolar macrophages induced by inhaled terbutaline in vivo is not counteracted by budesonide

Clinical Science ◽

10.1042/cs1000451 ◽

2001 ◽

Vol 100 (4) ◽

pp. 451-457 ◽

Cited By ~ 1

Author(s):

Anita ZETTERLUND ◽

Paul HJEMDAHL ◽

Kjell LARSSON

Keyword(s):

Alveolar Macrophages ◽

Control Group ◽

Transcriptional Level ◽

Down Regulation ◽

Bronchodilator Response ◽

Treatment Groups ◽

Before And After ◽

Β2 Agonist

In vitro studies suggest that glucocorticoids may counteract β-agonist-induced desensitization of β-adrenoceptors by actions at the transcriptional level, but the clinical relevance of such findings is not clear. Oral terbutaline treatment decreases β-adrenoceptor sensitivity in alveolar macrophages in vivo. This effect is not counteracted by inhaled or orally taken steroids. We therefore examined whether inhaled terbutaline elicited a similar effect on β2-adrenoceptor sensitivity in alveolar macrophages, and if co-treatment with an inhaled steroid, budesonide, would prevent such down-regulation. Bronchoalveolar lavage (BAL) and lung function tests, including bronchodilator responses to inhaled terbutaline, were performed before and after 2 weeks of regular inhalation of terbutaline, 0.5 mg three times daily, and budesonide, 400 µg twice daily, or placebo, in 24 healthy volunteers. Four untreated subjects served as controls. A marked, approx. 90%, decrease in isoprenaline-induced cAMP accumulation in alveolar macrophages was found in both treatment groups after 2 weeks, with no difference between placebo and budesonide (P = 0.45). In the untreated control group, cAMP responses to both isoprenaline and prostaglandin E1 tended to be lower on the second occasion. A limited, non-specific desensitization of adenylate cyclase activity thus contributed to the marked desensitization elicited by terbutaline inhalations. The bronchodilator response to inhaled terbutaline did not change after treatment in any of the three groups (F = 0.9, P = 0.50). In conclusion, inhalation of a β-agonist induced marked down-regulation of β2-adrenoceptor sensitivity in alveolar macrophages in vivo without influencing the bronchodilator response to a β2-agonist in healthy subjects. Co-treatment with an inhaled steroid failed to counteract the desensitization of alveolar macrophage β2-adrenoceptors.

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Effect of Hydrogen Peroxide on the Antibacterial Substantivity of Chlorhexidine

International Journal of Dentistry ◽

10.1155/2010/946384 ◽

2010 ◽

Vol 2010 ◽

pp. 1-4 ◽

Cited By ~ 3

Author(s):

Shahriar Shahriari ◽

Zahed Mohammadi ◽

Mohammadi Mehdi Mokhtari ◽

Rasoul Yousefi

Keyword(s):

Hydrogen Peroxide ◽

Antibacterial Activity ◽

Enterococcus Faecalis ◽

Time Lapse ◽

Positive Control ◽

Negative Control ◽

The Other ◽

Time Period ◽

Colony Forming Units

The purpose of thisin vitrostudy was to assess the effect of hydrogen peroxide on the antibacterial substantivity of chlorhexidine (CHX). Seventy-five dentine tubes prepared from human maxillary central and lateral incisor teeth were used. After contamination withEnterococcus faecalisfor 14 days, the specimens were divided into five groups as follows: CHX, H2O2, CHX + H2O2, infected dentine tubes (positive control), and sterile dentine tubes (negative control). Dentine chips were collected with round burs into tryptic soy broth, and after culturing, the number of colony-forming units (CFU) was counted. The number of CFU was minimum in the first cultures in all experimental groups, and the results obtained were significantly different from each other at any time period (). At the first culture, the number of CFU in the CHX + H2O2group was lower than other two groups. At the other experimental periods, the CHX group showed the most effective antibacterial action (). Hydrogen peroxide group showed the worst result at all periods. In each group, the number of CFU increased significantly by time lapse (). In conclusion, H2O2had no additive effect on the residual antibacterial activity of CHX.

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