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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 -
Journal of Applied Oral Science :... 2020The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types.
INTRODUCTION
The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types.
OBJECTIVE
To explore the influence of salivary pellicle formation before biofilm formation on enamel demineralization.
METHODOLOGY
Saliva collection was approved by Indiana University IRB. Three donors provided wax-stimulated saliva as the microcosm bacterial inoculum source. Acquired pellicle was formed on bovine enamel samples. Two groups (0.5% and 1% sucrose-supplemented growth media) with three subgroups (surface conditioning using filtered/pasteurized saliva; filtered saliva; and deionized water (DIW)) were included (n=9/subgroup). Biofilm was then allowed to grow for 48 h using Brain Heart Infusion media supplemented with 5 g/l yeast extract, 1 mM CaCl2.2H2O, 5% vitamin K and hemin (v/v), and sucrose. Enamel samples were analyzed for Vickers surface microhardness change (VHNchange), and transverse microradiography measuring lesion depth (L) and mineral loss (∆Z). Data were analyzed using two-way ANOVA.
RESULTS
The two-way interaction of sucrose concentration × surface conditioning was not significant for VHNchange (p=0.872), ∆Z (p=0.662) or L (p=0.436). Surface conditioning affected VHNchange (p=0.0079), while sucrose concentration impacted ∆Z (p<0.0001) and L (p<0.0001). Surface conditioning with filtered/pasteurized saliva resulted in the lowest VHNchange values for both sucrose concentrations. The differences between filtered/pasteurized subgroups and the two other surface conditionings were significant (filtered saliva p=0.006; DIW p=0.0075). Growing the biofilm in 1% sucrose resulted in lesions with higher ∆Z and L values when compared with 0.5% sucrose. The differences in ∆Z and L between sucrose concentration subgroups was significant, regardless of surface conditioning (both p<0.0001).
CONCLUSION
Within the study limitations, surface conditioning using human saliva does not influence biofilm-mediated enamel caries lesion formation as measured by transverse microradiography, while differences were observed using surface microhardness, indicating a complex interaction between pellicle proteins and biofilm-mediated demineralization of the enamel surface.
Topics: Animals; Biofilms; Cattle; Dental Enamel; Dental Pellicle; Hardness; Microradiography; Pasteurization; Reference Values; Saliva; Sucrose; Surface Properties; Tooth Demineralization
PubMed: 32236356
DOI: 10.1590/1678-7757-2019-0501 -
Journal of Applied Oral Science :... 2010Despite a plethora of in situ studies and clinical trials evaluating the efficacy of fluoridated dentifrices on caries control, in vitro pH cycling models are still... (Comparative Study)
Comparative Study Review
Despite a plethora of in situ studies and clinical trials evaluating the efficacy of fluoridated dentifrices on caries control, in vitro pH cycling models are still broadly used because they mimic the dynamics of mineral loss and gain involved in caries formation. This paper critically reviews the current literature on existing pH-cycling models for the in vitro evaluation of the efficacy of fluoridated dentifrices for caries control, focusing on their strengths and limitations. A search was undertaken in the MEDLINE electronic journal database using the keywords "pH-cycling", "demineralization", "remineralization", "in vitro", "fluoride", "dentifrice". The primary outcome was the decrease of demineralization or the increase of remineralization as measured by different methods (e.g.: transverse microradiography) or tooth fluoride uptake. Inclusion of studies, data extraction and quality assessment were undertaken independently and in duplicate by two members of the review team. Disagreements were solved by discussion and consensus or by a third party. One hundred and sixteen studies were included, of which 42 addressed specifically the comparison of dentifrices using different pH-cycling models. The other studies included meta-analysis or reviews, data about the effect of different fluoride sources on de-remineralization, different methods for analysis de-remineralization and chemical variables and characteristics of dental hard tissues that might have influence on de-remineralization processes. Generally, the studies presented ability to detect known results established by clinical trials, to demonstrate dose-related responses in the fluoride content of the dentifrices, and to provide repeatability and reproducibility between tests. In order to accomplish these features satisfactorily, it is mandatory to take into account the type of substrate and baseline artificial lesion, as well as the adequate response variables and statistical approaches to be used. This critical review of literature showed that the currently available pH-cycling models are appropriate to detect dose-response and pH-response of fluoride dentifrices, and to evaluate the impact of new active principles on the effect of fluoridated dentifrices, as well as their association with other anti-caries treatments.
Topics: Animals; Cariostatic Agents; Dental Caries; Dentifrices; Dose-Response Relationship, Drug; Fluorides; Humans; Hydrogen-Ion Concentration; Reproducibility of Results; Tooth Demineralization; Tooth Remineralization
PubMed: 20835565
DOI: 10.1590/s1678-77572010000400002 -
Molecules (Basel, Switzerland) Jan 2021Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate...
Developing artificial caries lesions with varying characteristics is needed to adequately study caries process in vitro. The objective of this study was to investigate artificial caries lesion characteristics after secondary demineralization protocol containing theobromine and fluoride. Sixty bovine enamel slabs (4 × 3 mm) were demineralized using a Carbopol-containing protocol for 6 days. A baseline area (2 × 3 mm) was protected with acid-resistant nail varnish, after which specimens were exposed for 24 h to a secondary demineralization protocol containing acetic acid plus one of four fluoride/theobromine combinations ( = 15): theobromine (50 or 200 ppm) and fluoride (0 or 1 ppm). Specimens were sectioned and analyzed using transverse microradiography for changes in mineral content, lesion depth, and surface layer mineralization. Data was analyzed using paired t-test and analysis of variance followed by Bonferroni test at 0.05 significance level. After secondary demineralization, fluoride-containing groups had significantly deeper lesions ( = 0.002 and 0.014) compared to the group with 0 ppm fluoride and 50 ppm theobromine. Mineral content and lesion depth were significantly different compared to baseline for all groups. Theobromine did not show an added effect on mineral uptake. Theobromine-containing groups exhibited particularly deep lesions with a more uniform mineral profile in the presence of fluoride.
Topics: Animals; Bronchodilator Agents; Cattle; Dental Caries; Dental Enamel; Fluorides; Theobromine; Tooth; Tooth Demineralization
PubMed: 33435546
DOI: 10.3390/molecules26020300 -
Clinical Oral Investigations Jun 2021The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained...
OBJECTIVES
The aim of this study was to evaluate the influence of different bleaching gels on the masking and caries-arresting effects of infiltrated and non-infiltrated stained artificial enamel caries lesions.
MATERIALS AND METHODS
Bovine enamel specimens (n = 240) with each two sound areas (SI and SC) and each two lesions (DI and DC) were infiltrated (DI and SI), stained (1:1 red wine-coffee mixture,70 days), and randomly distributed in six groups to be bleached with the following materials: 6%HP (HP-6), 16%CP (CP-16), 35%HP (HP-35), 40%HP (HP-40), and no bleaching (NBl,NBl-NBr). Subsequently, specimens were pH-cycled (28 days, 6 × 60 min demineralization/day) and all groups except NBl-NBr were brushed with toothpaste slurry (1.100 ppm, 2×/day, 10 s). Differences in colorimetric values (ΔL, ΔE) and integrated mineral loss (ΔΔZ) between baseline, infiltration, staining, bleaching, and pH cycling were calculated using photographic and transversal microradiographic images.
RESULTS
At baseline, significant visible color differences between DI and SC were observed (ΔE = 12.2; p < 0.001; ANCOVA). After infiltration, these differences decreased significantly (ΔE = 3.8; p < 0.001). Staining decreased and bleaching increased ΔL values significantly (p ≤ 0.001). No significant difference in ΔΔE was observed between before staining and after bleaching (ΔE = 4.3; p = 0.308) and between the bleaching agents (p = 1.000; ANCOVA). pH-cycling did not affect colorimetric values (ΔE = 4.0; p = 1.000). For DI, no significant change in ΔZ during in vitro period was observed (p ≥ 0.063; paired t test).
CONCLUSIONS
Under the conditions chosen, the tested materials could satisfactorily bleach infiltrated and non-infiltrated stained enamel. Furthermore, bleaching did not affect the caries-arresting effect of the infiltration.
CLINICAL RELEVANCE
The present study indicates that bleaching is a viable way to satisfactorily recover the appearance of discolored sound enamel and infiltrated lesions.
Topics: Animals; Cattle; Dental Caries; Dental Caries Susceptibility; Dental Enamel; Gels; Hydrogen Peroxide; Microradiography; Tooth Bleaching; Tooth Bleaching Agents
PubMed: 33319337
DOI: 10.1007/s00784-020-03732-4 -
Australian Dental Journal Jun 2016This study compared the effects of three flavonoids, including proanthocyanidin, naringin and quercetin on remineralization of artificial root caries.
BACKGROUND
This study compared the effects of three flavonoids, including proanthocyanidin, naringin and quercetin on remineralization of artificial root caries.
METHODS
Demineralized root fragments (n = 75) were randomly divided into five groups for treatment with the remineralizing agents for 10 minutes: (1) 6.5% proanthocyanidin; (2) 6.5% naringin; (3) 6.5% quercetin; (4) 1000 ppm fluoride; and (5) deionized water (control). The demineralized samples were pH-cycled through treatment solutions, acidic buffer and neutral buffer for eight days at six cycles per day. The remineralization effects were evaluated using Knoop microhardness, transverse microradiography (lesion depth and mineral loss) and confocal laser scanning microscopy. Microhardness at different lesion depths was analysed with two-way ANOVA and Tukey's test, while lesion depths and mineral loss were analysed with one-way ANOVA and Tukey's test.
RESULTS
Artificial caries lesions treated with fluoride and flavonoids showed significantly greater hardness than the control group (p < 0.05). Both lesion depths and mineral loss of the flavonoid treated groups were significantly lower than the control group (p < 0.05), but significantly higher than the fluoride treated group. No significant difference in lesion depth and mineral loss was found among the three flavonoids (p > 0.05).
CONCLUSIONS
All three flavonoids showed positive effects on artificial root caries remineralization, which are significantly lower than that of 1000 ppm fluoride.
Topics: Analysis of Variance; Antioxidants; Cariostatic Agents; Dental Enamel; Flavanones; Humans; Microradiography; Molar, Third; Proanthocyanidins; Quercetin; Root Caries; Tooth Remineralization; Tooth Root
PubMed: 26296390
DOI: 10.1111/adj.12367 -
BDJ Open Jun 2024The effectiveness of an Isomalt-containing mouthrinse to prevent caries development was investigated.
OBJECTIVES
The effectiveness of an Isomalt-containing mouthrinse to prevent caries development was investigated.
METHODS
Human enamel blocks were randomly assigned to five groups (n = 30/group): De-ionized distilled water (DDW), and mouthrinse containing either (IFC) 1% Isomalt, 225 ppm fluoride, and 0.05% cetylpyridinium chloride (CPC), (IF) 1% Isomalt and 225ppm fluoride, (FC) 225 ppm fluoride and 0.05% CPC or (F) 225 ppm fluoride. During 7-day demineralization in a Microbial Caries Model, mouthrinses were applied once daily for 1 min. Demineralization was assessed using Surface Microhardness testing for percentage change in SMH (%ΔSMH) and Transverse Microradiography for mineral loss (ΔZ). Data analysis (α = 0.05) used paired t-test (Intra-group comparison using SMH) and ANOVA/Tukey's for inter-group comparisons (%ΔSMH and ΔZ).
RESULTS
With SMH, relative to sound enamel baseline, demineralization was significant (P < 0.001) in all groups, except in IFC. Intergroup comparison with %ΔSMH showed significantly (p < 0.001) greater demineralization in DDW compared to other groups, and in IF, FC, and F compared to IFC (P < 0.001). With ΔZ, relative to DDW, all groups significantly (p < 0.0001) inhibited demineralization at varying percentages.
CONCLUSIONS
Mouthrinse containing Isomalt, fluoride, and CPC inhibited demineralization amidst cariogenic biofilm; thus, highlighting its potential as a more effective caries control tool than mouthrinse with only fluoride.
PubMed: 38890317
DOI: 10.1038/s41405-024-00241-4 -
Journal of Applied Oral Science :... 2022Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid.. Evaluate preventive methods against root collagen...
OBJECTIVES
Quantification of collagen degradation is an important parameter to evaluate dentin caries for preventive aid.. Evaluate preventive methods against root collagen degradation by the hydroxyproline assay (HYP) and microradiography technique (MRT).
METHODOLOGY
Five bovine root dentin blocks were obtained and subjected to an artificial demineralization process by acetate buffer (pH 5) to induce carious lesion formation. Samples were subjected to the following therapeutic treatments: 1) 0.12% chlorhexidine for 1 min, 2) 2% fluoride for 1 min, 3) Nd:YAG Laser (400 μm diameter optical fiber, 10 Hz frequency, 60 mJ/pulse energy, 48 J/cm2 energy density, in noncontact mode for 10 s), 4) deionized water (control) for 1 min, 5) MRT control group (without treatment and removal of collagen). Samples were exposed to degradation by a collagenase enzyme for five days. The enzyme solution was collected, by colorimetry in a spectrophotometer, from the collagen matrix for the hydroxyproline release analysis. The same samples were subjected to an additional two days of demineralization to induce the progression of mineral loss. Samples were analyzed by MRT for the visualization of their degraded areas (estimation of lesion depth and mineral loss). ANOVA was applied to compare hydroxyproline release rates. MRT data were subjected to the Kruskal-Wallis test, followed by the Dunn's test. Comparisons between the initial five-day and the subsequent two-day demineralization processes were performed by repeated t-test or Wilcoxon (p<0.05) measurements.
RESULTS
The amount of HYP released from the dentin samples failed to show significant differences among the groups (p=0.09). Fluoride and chlorhexidine were able to interact with the samples, reducing the progression of dentin caries after removal of the demineralized organic matrix. CHX was the only treatment able to show significant lower lesion depth than the negative control.
CONCLUSION
Chlorhexidine and fluoride were effective in reducing root caries progression.
Topics: Animals; Cattle; Chlorhexidine; Dentin; Fluorides; Root Caries; Tooth Demineralization
PubMed: 35293423
DOI: 10.1590/1678-7757-2021-0496 -
Blood Feb 1977A 69-yr-old man with persistent anemia had multiple myeloma with an IgE-type kappa M component and Bence Jones proteinuria. Bone x-rays revealed occasional lytic lesions...
A 69-yr-old man with persistent anemia had multiple myeloma with an IgE-type kappa M component and Bence Jones proteinuria. Bone x-rays revealed occasional lytic lesions associated with a diffuse sclerotic reaction throughout the skeleton. Special bone histologic studies utilizing tetracycline labeling, undercalcified sections, and microradiography confirmed active osteoblastic activity. This case was compared with the four previously reported cases of IgE myeloma, one of which also had osteosclerosis.
Topics: Aged; Fluorescent Antibody Technique; Humans; Immunoglobulin E; Male; Multiple Myeloma; Osteoblasts
PubMed: 318876
DOI: No ID Found -
Dental Materials Journal Mar 2021This study investigated the anti-demineralization effects of surface pre-reacted glass-ionomer (S-PRG) filler-containing varnishes. Thirty-five bovine root specimens...
This study investigated the anti-demineralization effects of surface pre-reacted glass-ionomer (S-PRG) filler-containing varnishes. Thirty-five bovine root specimens were divided into five treatment groups, with seven specimens each coated with 1) MI varnish (MIV), 2) F varnish (FV), 3) PRG varnish I (PV), 4) PRG varnish II (with sodium fluoride added, PVF), and 5) acid-resistant nail varnish (Control). A 3×1 mm area of the dentin surface adjacent to each varnish was demineralized for one week at 37°C. Integrated mineral loss (IML) of these lesions was determined by transverse microradiography, as was the amount of fluoride released by each material. IML was significantly lower in the PV and PVF groups than in the Control group, and was significantly lower in the PVF than in the MIV and FV groups. These findings indicated that S-PRG filler-containing varnishes, especially varnish containing sodium fluoride, had superior anti-demineralization effects on root dentin.
Topics: Animals; Cattle; Fluorides; Microradiography; Sodium Fluoride; Tooth Demineralization
PubMed: 33177310
DOI: 10.4012/dmj.2019-396