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Antimicrobial Agents and Chemotherapy May 2019Biofilm control is a critical approach to the better management of dental caries. Antimicrobial small molecules have shown their potential in the disruption of oral...
Biofilm control is a critical approach to the better management of dental caries. Antimicrobial small molecules have shown their potential in the disruption of oral biofilm and control of dental caries. The objectives of this study were to examine the antimicrobial activity and cytotoxicity of a newly designed small-molecule compound, ZY354. ZY354 was synthesized, and its cytotoxicity was evaluated in human oral keratinocytes (HOK), human gingival epithelial cells (HGE), and macrophages (RAW) by CCK-8 assays. Minimal inhibitory concentrations (MICs), minimum bactericidal concentrations (MBCs), minimum biofilm inhibition concentrations (MBICs), and minimum biofilm reduction concentrations (MBRCs) of ZY354 against common oral streptococci (i.e., , , and ) were determined by microdilution method. The exopolysaccharide (EPS)/bacterium ratio and the dead/live bacterium ratio in the ZY354-treated multispecies biofilms were determined by confocal laser scanning microscopy, and the microbial composition was visualized and quantified by fluorescent hybridization and quantitative PCR (qPCR). The demineralizing activity of ZY354-treated biofilms was evaluated by transverse microradiography. The results showed that ZY354 exhibited low cytotoxicity in HOK, HGE, and RAW cells and exhibited potent antimicrobial activity against common oral streptococci. The EPS and the abundance of were significantly reduced after ZY354 treatment, along with an increased dead/live microbial ratio in multispecies biofilms compared to the level with the nontreated control. The ZY354-treated multispecies biofilms exhibited reduced demineralizing activity at the biofilm/enamel interface. In conclusion, the small-molecule compound ZY354 exhibits low cytotoxicity and remarkable antimicrobial activity against oral streptococci, and it may have a great potential in anticaries clinical applications.
Topics: Anti-Infective Agents; Biofilms; Dental Caries; Molecular Structure; Streptococcus; Streptococcus gordonii; Streptococcus mutans; Streptococcus sanguis
PubMed: 30858201
DOI: 10.1128/AAC.02414-18 -
PloS One 2014Dental caries is the most prevalent disease encountered by people of all ages around the world. Chemical changes occurring in the oral environment during the caries...
Dental caries is the most prevalent disease encountered by people of all ages around the world. Chemical changes occurring in the oral environment during the caries process alter the crystallography and microstructure of dental enamel resulting in loss of mechanical function. Little is known about the crystallographic effects of demineralization and remineralization. The motivation for this study was to develop understanding of the caries process at the crystallographic level in order to contribute towards a long term solution. In this study synchrotron X-ray diffraction combined with scanning electron microscopy and scanning microradiography have been used to correlate enamel crystallography, microstructure and mineral concentration respectively in enamel affected by natural caries and following artificial demineralization and remineralization regimes. In particular, the extent of destruction and re-formation of this complex structure has been measured. 2D diffraction patterns collected at the European Synchrotron Radiation Facility were used to quantify changes in the preferred orientation (crystallographic texture) and position of the (002) Bragg reflection within selected regions of interest in each tooth slice, and then correlated with the microstructure and local mineral mass. The results revealed that caries and artificial demineralization cause a large reduction in crystallographic texture which is coupled with the loss of mineral mass. Remineralization restores the texture to the original level seen in healthy enamel and restores mineral density. The results also showed that remineralization promotes ordered formation of new crystallites and growth of pre-existing crystallites which match the preferred orientation of healthy enamel. Combining microstructural and crystallographic characterization aids the understanding of caries and erosion processes and assists in the progress towards developing therapeutic treatments to allow affected enamel to regain structural integrity.
Topics: Crystallography; Dental Caries; Dental Enamel; Humans; Microradiography; Microscopy, Electron, Scanning; Minerals; Molar; Reference Values; Synchrotrons; Tooth Demineralization; Tooth Remineralization; X-Ray Diffraction
PubMed: 25360532
DOI: 10.1371/journal.pone.0108879 -
Microorganisms Aug 2020While 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...
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, and , on a continuous-cultured model containing , and . Cariogenic biofilms were grown on bovine enamel specimens and daily challenged with or whole culture (LC/SC) or cell-free supernatant (LS/SS) or medium only (negative control, NC) ( = 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 ( < 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, < 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 and , but not their culture supernatants, could reduce the caries activity of multi-species biofilms .
PubMed: 32825575
DOI: 10.3390/microorganisms8091272 -
Journal of International Society of... 2022To evaluate self-assembling peptides (SAP) for caries prevention and arrest in primary tooth enamel .
OBJECTIVES
To evaluate self-assembling peptides (SAP) for caries prevention and arrest in primary tooth enamel .
MATERIALS AND METHODS
Overall, 180 extracted primary teeth were used. In the prevention experiment ( = 20 samples per group), self-assembling peptide for prevention (SAPP), fluoride varnish/mouthwash (FV/FMW), casein-phosphopeptide amorphous-calcium phosphate (CPP-ACP), and nanohydroxyapatite (nHA) were applied. Samples were subjected to a demineralizing pH cycling for 14 days. In the arrest experiment ( = 15/group), 60 samples were pre-demineralized; induced lesions were treated using self-assembling peptide for repair (SAPR), FV, CPP-ACP plus fluoride, and resin infiltration (RI) and submitted to pH cycling. Mineral loss and its differences as well as lesion depth were determined using transversal microradiography. Numerical data were tested for normality using Shapiro-Wilk's test and were compared using Kruskal-Wallis test followed by pairwise comparisons utilizing multiple Mann-Whitney U tests with Bonferroni correction. The significance level was set at < 0.05 within all tests.
RESULTS
FV (median: -46.3 [interquartile range: 175.52] vol% × µm) and FMW (-33.35 [124.65] vol% × µm) prevented caries significantly more effectively than all other groups ( < 0.001), which did not show significant preventive effects. RI (median: 4949.70 [1637.20] vol% × µm) and FV (median = 6076.05 [5190.08] vol% × µm) arrested lesions, whereas SAPR and CPP-ACPF did not show such arrest.
CONCLUSIONS
FV and FMW showed the largest caries-preventive effect, whereas RI and FV arrested lesion progression in primary tooth enamel .
PubMed: 35281691
DOI: 10.4103/jispcd.JISPCD_257_21 -
PloS One 2018[This corrects the article DOI: 10.1371/journal.pone.0183432.].
[This corrects the article DOI: 10.1371/journal.pone.0183432.].
PubMed: 29377942
DOI: 10.1371/journal.pone.0192270 -
Australian Dental Journal Sep 2012Quantitative light-induced fluorescence (QLF) and digital photography (DP) have been proposed as clinical methods for measuring changes in enamel mineral content. The... (Comparative Study)
Comparative Study
BACKGROUND
Quantitative light-induced fluorescence (QLF) and digital photography (DP) have been proposed as clinical methods for measuring changes in enamel mineral content. The aim of this study was to compare the ability of QLF and DP with the in vitro gold standard transverse microradiography (TMR) to measure the remineralization of enamel subsurface lesions.
METHODS
Subsurface lesions were formed in enamel (n = 40) and exposed to remineralization solutions for 10 days. Changes were analysed by DP, QLF and TMR to determine percentage changes in luminescence (%L), fluorescence (%F) and mineral content (%R), respectively and correlation between these parameters determined.
RESULTS
The correlations between TMR and QLF (r = 0.63), TMR and DP (r = 0.59), and DP and QLF (r = 0.64) were all moderate but statistically significant (p < 0.001). The variability in %L and, to a lesser extent, %F values significantly impacted on the potential role of DP and QLF as methods by which mineral content changes produced by remineralization treatments could be accurately measured.
CONCLUSIONS
Both QLF and DP provided data that correlated moderately with TMR data. QLF images were easier to analyse, free of glare and had less variability compared with those produced using DP.
Topics: Dental Caries; Dental Enamel; Fluorescence; Humans; Linear Models; Microradiography; Photography, Dental; Radiography, Dental; Tooth Remineralization
PubMed: 22924348
DOI: 10.1111/j.1834-7819.2012.01706.x -
Microorganisms Apr 2021Caries preventive varnishes containing only fluoride might differ from those containing a combination of fluoride and antimicrobial components in terms of mineralization...
Caries preventive varnishes containing only fluoride might differ from those containing a combination of fluoride and antimicrobial components in terms of mineralization properties and their impact on the cariogenic biofilm. We compared a fluoride and a fluoride + chlorhexidine (CHX)/cetylpyridinium chloride (CPC) varnish on root caries formation in vitro. One hundred bovine root dentin samples were allocated to five groups ( = 20/group): (1) 7700 ppm fluoride varnish (Fluorprotector S (F)), (2) experimental placebo varnish for F (F-P), (3) 1400 ppm fluoride + 0.3% CHX/0.5% CPC varnish (Cervitec F (CF)), (4) experimental placebo varnish for CF (CF-P), (5) untreated control. Cariogenic challenge was provided using a multi-station, continuous-culture 3-species ( (SM), (LR), (AN)) biofilm model for 10 days. Mineral loss (ΔZ) was evaluated using transversal microradiography and bacterial counts in the biofilm assessed as colony-forming units. Fluorescence in situ hybridization (FISH) and confocal microscopy were performed to assess the three-dimensional biofilm architecture. Mean ± SD (vol% × μm) ΔZ was significantly lower for F (9133 ± 758) and CF (9835 ± 1677) compared to control (11362 ± 919) ( < 0.05), without significant differences between F and CF. SM counts were significantly lower and LR counts significantly higher in F- and CF-biofilms compared to control. AN counts were significantly higher in the F-biofilms than in all other groups. According to FISH, SM and LR invaded dentinal tubules only in the control-group. In the CF-group, the basal biofilm layer did not contain SM and AN. Both F and CF varnishes had similar caries-preventive effects and a considerable impact on biofilm structure and composition.
PubMed: 33916105
DOI: 10.3390/microorganisms9040737 -
Caries Research 2014Determination of the potential of cerium chloride to reduce artificial carious mineral loss and lesion depth progression. (Comparative Study)
Comparative Study
AIM
Determination of the potential of cerium chloride to reduce artificial carious mineral loss and lesion depth progression.
METHODS
A total of 160 enamel samples were prepared from 40 bovine lower central incisors. Crowns were sectioned into four pieces, embedded in acrylic resin, ground flat and allocated to eight groups (S1-S4 and D1-D4; n = 20). Specimens of groups D1-D4 were stored (for 7 days) in a demineralizing buffer solution to induce caries-like lesions. Afterwards, samples were treated for 30 s with one of the following solutions: placebo (S1 and D1), amine fluoride (S2 and D2), cerium chloride (S3 and D3) and a combination of fluoride and cerium chloride (S4 and D4). After another 7 (D1-D4) or 14 (S1-S4) days in demineralizing buffer solution, integrated mineral loss and lesion depth were determined by transversal microradiography and compared by Scheffé's post hoc tests.
RESULTS
In groups S1-S4, the highest values for integrated mineral loss and lesion depth were observed for group S1 (placebo), the lowest values for group S4. The results in groups S2-S4 were not significantly different. In groups D1-D4, the highest values for integrated mineral loss and lesion depth were observed for group D1 (placebo), the lowest values in groups D3 and D4. In group D2, integrated mineral loss and lesion depth were significantly lower as compared to D1, but significantly higher compared to groups D3 and D4.
CONCLUSION
Cerium chloride and its combination with fluoride are able to significantly reduce carious mineral loss and the progression of lesion depth.
Topics: Animals; Cariostatic Agents; Cattle; Cerium; Dental Enamel; Diamines; Disease Progression; Drug Combinations; Fluorides; Microradiography; Minerals; Placebos; Time Factors; Tooth Demineralization
PubMed: 24247975
DOI: 10.1159/000351691 -
Dentistry Journal Oct 2017The aging population experiences more gingival recession and root exposure which increases the opportunity for dentin erosion. This study tested the use of transverse...
The aging population experiences more gingival recession and root exposure which increases the opportunity for dentin erosion. This study tested the use of transverse microradiography (TMR) methods to assess dentin erosion and the interaction between fluoride and citric acid on the amount of erosion in the dentin samples. In a 4 × 3 interaction experimental design, four fluoride concentrations (0.00, 25.0, 50.0, and 100.0 mg/L) and three citric acid concentrations (0.0, 0.25, and 1.00%) were combined to form 12 experimental solutions. Forty-eight dentin samples were placed in the experimental solutions for 1 and 4 h and the amount of surface lost was determined by TMR methods. The resolution of the TMR method was 0.9 μm per pixel with a 0.1% and a 5% confidence interval of ±4.2 μm. Dentin erosion increased with the concentration of citric acid and time, the erosion decreased when concentration of fluoride was increased. Effects due to fluoride and citric acid concentrations individually, and their interaction on the amount of erosion observed was statistically significant (p < 0.0001). This study found that TMR methods are appropriate and that 25.0 mg/L was the optimal fluoride concentration to protect dentin from a 1.00% citric acid challenge.
PubMed: 29563433
DOI: 10.3390/dj5040027 -
The Chinese Journal of Dental Research 2020To explore the self-assembly and gelation properties of synthetic peptides, and their efficacy on hydroxyapatite (HAP) nucleation and in situ remineralisation of initial...
OBJECTIVE
To explore the self-assembly and gelation properties of synthetic peptides, and their efficacy on hydroxyapatite (HAP) nucleation and in situ remineralisation of initial caries lesions.
METHODS
Mass spectrometry and reversed-phase high performance liquid chromatography (RPHPLC) were used to confirm the successful synthesis of peptides. Their self-assembly properties and conformation stability were evaluated using circular dichroism (CD) spectroscopy and Fourier-transform infrared spectroscopy (FTIR). Cell Counting Kit-8 (CCK-8; Dojindo, Kumamoto, Japan) was used to evaluate their cytotoxicity. The efficacy of the peptides on HAP nucleation and in situ remineralisation of initial caries lesions was explored using FTIR, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction and transverse microradiography analysis.
RESULTS
Two kinds of self-assembly β-sheet peptides named ID4 and ID8, respectively, were successfully synthesised with purities greater than 95%. Both were stable under neutral physiological conditions and had low cytotoxicity. ID4 and ID8 showed calcium responsive self-assembly properties and could self-assemble into nanofibres. Compared with ID4, ID8 resulted in the rapid formation of hydrogel with a lower concentration of calcium, and self-assembled ID8 hydrogel induced the formation of flower-like HAP and significantly promoted the remineralisation of initial enamel caries.
CONCLUSION
ID8 could serve as the template to induce HAP nucleation and promote biomimetic remineralisation of initial caries lesions. These results underpin future research on peptide design, and ID8 may be a promising bioactive component for anti-caries applications.
Topics: Cariostatic Agents; Dental Caries; Humans; Nanofibers; Peptides; Protein Conformation, beta-Strand; Tooth Remineralization
PubMed: 32548604
DOI: 10.3290/j.cjdr.a44749