The Effect of Copper on Demineralization of Dental Enamel

2006 ◽  
Vol 85 (11) ◽  
pp. 1011-1015 ◽  
Author(s):  
A.Z. Abdullah ◽  
S.M. Strafford ◽  
S.J. Brookes ◽  
M.S. Duggal

Previous studies have concluded that copper might inhibit enamel demineralization in vitro. Our aim was to assess the effect of copper (Cu2+), with and without amine fluoride, on human dental enamel under cariogenic challenge in situ. In a double-blind randomized four-leg crossover trial, 14 individuals wore a removable appliance containing 2 enamel slabs, 1 containing an artificial caries lesion. During each leg, the appliance was exposed twice daily to one of the test solutions: 1.25 mM CuSO4, amine fluoride (250 ppm F), copper and amine fluoride combined, or a placebo (water). A cariogenic challenge was provided in all cases by 5 daily exposures to 10% sucrose. Slabs were assessed before and after 21 days’ exposure by Knoop microhardness and transverse microradiography. Significantly less demineralization was observed with Cu2+ and fluoride in combination than with fluoride treatment alone (p < 0.05), whereas copper alone had no significant protective effect.

2014 ◽  
Vol 8 (1) ◽  
pp. 188-193 ◽  
Author(s):  
Ana L.P China ◽  
Nayara M Souza ◽  
Yasmin do S. B. de L Gomes ◽  
Larissa D Alexandrino ◽  
Cecy M Silva

The effect of bleaching treatments containing added calcium and combined with neutral or acidic fluoride gels on tooth enamel was investigated in vitro through Knoop microhardness (KHN) and surface roughness (SR) measurements. A total of 60 bovine incisors were tested, including 30 for SR measurements and 30 for KHN measurements. The specimens were divided into 12 groups and subjected to a bleaching agent with hydrogen peroxide 35% (Whiteness HP 35% Maxx, FGM) or hydrogen peroxide 35% with calcium (Whiteness HP 35% Blue Calcium, FGM) and a fluoride treatment flugel acidulated phosphate fluoride (APF) or flugel neutral fluoride (NF). Control specimens were submitted to bleaching treatments without fluoride. Microhardness tests were performed using a Knoop indentor. Roughness measurements were obtained using a roughness analyzer. Measurements were obtained before and after treatment. The specimens were stored in distilled water at 37 °C between treatments. The results were analyzed using descriptive and inferential statistics. Treatments using APF combined with 35% HP caused a decrease in microhardness, while NF combined with HP 35% Ca increased the enamel hardness. Fluoride gels did not alter the SR of the bleached enamel.


2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Janaína Salmos Brito ◽  
Alexandrino Santos Neto ◽  
Luciano Silva ◽  
Rebeca Menezes ◽  
Natália Araújo ◽  
...  

Objective. This paper aimed to analyze thein vitroindustrialized fruit juices effect plus soy to establish the erosive potential of these solutions.Materials and Methods. Seventy bovine incisors were selected after being evaluated under stereomicroscope. Their crowns were prepared and randomly divided into 7 groups, using microhardness with allocation criteria. The crowns were submitted to the fruit juice plus soy during 15 days, twice a day. The pH values, acid titration, and Knoop microhardness were recorded and the specimens were evaluated using X-ray microfluorescence (µXRF).Results. The pH average for all juices and after 3 days was significantly below the critical value for dental erosion. In average, the pH value decreases 14% comparing initial time and pH after 3 days. Comparing before and after, there was a 49% microhardness decrease measured in groups (p<0.05). Groups G1, G2, G5, and G6 are above this average. The analysis byμXRF showed a decrease of approximately 7% Ca and 4% P on bovine crowns surface. Florida (FL) statistical analysis showed a statistically significant 1 difference between groups. Thus, a tooth chance to suffer demineralization due to industrialized fruit juices plus soy is real.


Author(s):  
M. John Hicks

Acid-etching of enamel surfaces has been performed routinely to bond adhesive resin materials to sound dental enamel as a caries-preventive measure. The effect of fluoride pretreatment on acid-etching of enamel has been reported to produce inconsistent and unsatisfactory etching patterns. The failure to obtain an adequate etch has been postulated to be due to fluoride precipitation products deposited on the enamel surface. The purpose of this study was to evaluate the effects of fluoride pretreatment on acid-etching of carieslike lesions of human dental enamel.Caries-like lesions of enamel were created in vitro on human molar and premolar teeth. The teeth were divided into two fluoride treatment groups. The specimens were exposed for 4 minutes to either a 2% Sodium Fluoride (NaF) solution or a 10% Stannous Fluoride (SnF2) solution. The specimens were then washed in deionized-distilled water. Each tooth was sectioned into four test regions. This was carried out to compare the effects of various time exposures (0 to 2 minutes) and differing concentrations (10 to 60% w/w) of phosphoric acid (H3PO4) on etching of caries-like lesions. Standard preparation techniques for SEM were performed on the specimens.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 566
Author(s):  
Pham Hong Quan ◽  
Iulian Antoniac ◽  
Florin Miculescu ◽  
Aurora Antoniac ◽  
Veronica Manescu (Păltânea) ◽  
...  

Fluoride conversion coatings on Mg present many advantages, among which one can find the reduction of the corrosion rate under “in vivo” or “in vitro” conditions and the promotion of the calcium phosphate deposition. Moreover, the fluoride ions released from MgF2 do not present cytotoxic effects and inhibit the biofilm formation, and thus these treated alloys are very suitable for cardiovascular stents and biodegradable orthopedic implants. In this paper, the biodegradation behavior of four new magnesium biodegradable alloys that have been developed in the laboratory conditions, before and after surface modifications by fluoride conversion (and sandblasting) coatings, are analyzed. We performed structural and surface analysis (XRD, SEM, contact angle) before and after applying different surface treatments. Furthermore, we studied the electrochemical behavior and biodegradation of all experimental samples after immersion test performed in NaCl solution. For a better evaluation, we also used LM and SEM for evaluation of the corroded samples after immersion test. The results showed an improved corrosion resistance for HF treated alloy in the NaCl solution. The chemical composition, uniformity, thickness and stability of the layers generated on the surface of the alloys significantly influence their corrosion behavior. Our study reveals that HF treatment is a beneficial way to improve the biofunctional properties required for the studied magnesium alloys to be used as biomaterials for manufacturing the orthopedic implants.


2020 ◽  
Vol 21 (20) ◽  
pp. 7459
Author(s):  
María Elena González-Benito ◽  
Miguel Ángel Ibáñez ◽  
Michela Pirredda ◽  
Sara Mira ◽  
Carmen Martín

Epigenetic variation, and particularly DNA methylation, is involved in plasticity and responses to changes in the environment. Conservation biology studies have focused on the measurement of this variation to establish demographic parameters, diversity levels and population structure to design the appropriate conservation strategies. However, in ex situ conservation approaches, the main objective is to guarantee the characteristics of the conserved material (phenotype and epi-genetic). We review the use of the Methylation Sensitive Amplified Polymorphism (MSAP) technique to detect changes in the DNA methylation patterns of plant material conserved by the main ex situ plant conservation methods: seed banks, in vitro slow growth and cryopreservation. Comparison of DNA methylation patterns before and after conservation is a useful tool to check the fidelity of the regenerated plants, and, at the same time, may be related with other genetic variations that might appear during the conservation process (i.e., somaclonal variation). Analyses of MSAP profiles can be useful in the management of ex situ plant conservation but differs in the approach used in the in situ conservation. Likewise, an easy-to-use methodology is necessary for a rapid interpretation of data, in order to be readily implemented by conservation managers.


2020 ◽  
pp. 1-14
Author(s):  
Daniel Erdwey ◽  
Hendrik Meyer-Lueckel ◽  
Marcella Esteves-Oliveira ◽  
Christian Apel ◽  
Richard Johannes Wierichs

<b><i>Objectives:</i></b> 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. <b><i>Methods:</i></b> Bovine dentin specimens (<i>n</i> = 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., AmF<sub>1450</sub>) or 5,000 ppm (e.g., AmF<sub>5000</sub>). Differences in integrated mineral loss (ΔΔZ) and lesion depth (ΔLD) were calculated between values before and after pH-cycling using transversal microradiography. <b><i>Results:</i></b> After pH-cycling Ss showed significantly increased ΔZ<sub>DT</sub> and LD<sub>DT</sub> values, indicating further demineralization. In contrast, except for one, all groups including fluoride gels/solutions showed significantly decreased ΔZ<sub>DT</sub> 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. <b><i>Significance:</i></b> 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.


BDJ Open ◽  
2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Bennett T. Amaechi ◽  
Parveez Ahamed AbdulAzees ◽  
Dina Ossama Alshareif ◽  
Marina Adel Shehata ◽  
Patrícia Paula de Carvalho Sampaio Lima ◽  
...  

Abstract Objective This in situ study compared the effectiveness of two toothpastes containing hydroxyapatite or 500 ppm fluoride in promoting remineralization and inhibiting caries development. Materials and methods Two enamel blocks (human primary teeth), one sound and one with artificially-produced caries lesion, were exposed to toothpaste containing either 10% hydroxyapatite or 500 ppm F− (amine fluoride) via intra-oral appliance worn by 30 adults in two-arm double blind randomized crossover study lasting 14 days per arm (ClinicalTrials.gov: NCT03681340). Baseline and post-test mineral loss and lesion depth (LD) were quantified using microradiography. One-sided t-test of one group mean was used for intragroup comparison (baseline vs. post-test), while two-sided t-test of two independent means was used to compare the two toothpaste groups. Results Pairwise comparison (baseline vs. test) indicated significant (p < 0.0001) remineralization and LD reduction by either toothpaste; however, when compared against each other, there was no statistically significant difference in remineralization or LD reduction between the two toothpastes. No demineralization could be observed in sound enamel blocks exposed to either toothpaste. While F− induced lesion surface lamination, HAP produced a more homogenous lesion remineralization. Conclusions 10% hydroxyapatite achieved comparable efficacy with 500 ppm F− in remineralizing initial caries and preventing demineralization. Thus the HAP toothpaste is confirmed to be equal to the fluoride toothpaste in this study.


2016 ◽  
Vol 17 (3) ◽  
pp. 192-197
Author(s):  
Yasmin do Socorro Batista de Lima Gomes ◽  
Larissa Dias Alexandrino ◽  
Cecy Martins Silva ◽  
Thiago da Rosa Nogueira ◽  
Cristiane de Melo Alencar ◽  
...  

ABSTRACT Aim The aim of this study was to use surface rugosity analysis (Ra) and scanning electron microscopy (SEM) comparing effects of nano-hydroxyapatite (NANO), casein phosphopeptideamorphous calcium phosphate (CPP-ACP), and NovaMin (NOVA) on enamel's human morphology bleached with 37.5% hydrogen peroxide. Materials and methods Forty specimens (3 × 3 × 3 mm) were obtained from fully included third molars and four specimens were attached in the first molars of the volunteers. The POLApositive control has only been bleached. Three experimental groups were bleached and treated with respective bioactive: NANO, CPP-ACP, and NovaMin. The Ra analyses were performed before and after the treatment using a rugosimeter. The obtained photomicrographs were analyzed using SEM (n = 3) by three examiners, and the study was double blind. Results The Ra results were analyzed by one-way analysis of variance and Tukey's post hoc test (p < 0.05). All experimental groups showed significant differences of the others; however, the experimental groups were not significantly different from each other. Conclusion The enamel morphology of the bioactive-treated groups had more regular surfaces, than the others. How to cite this article da Rosa Nogueira T, Alexandrino LD, de Lima Gomes YSB, de Melo Alencar C, Alves EB, Silva CM. An in situ evaluation of Bioactives on the morphology of bleached Enamel. J Contemp Dent Pract 2016;17(3):192-197.


2017 ◽  
Vol 11 (1) ◽  
pp. 34-40
Author(s):  
Thais de Mendonça Petta ◽  
Yasmin do Socorro Batista de Lima Gomes ◽  
Renata Antunes Esteves ◽  
Kelson do Carmo Freitas Faial ◽  
Roberta Souza D`Almeida Couto ◽  
...  

Background: Dental whitening has been increasingly sought out to improve dental aesthetics, but may cause chemical and morphological changes in dental enamel surfaces. Objective: Assess in situ the effects of high-concentration hydrogen peroxide with and without fluoride on human dental enamel using the ion chromatography test (IC) and the Knoop hardness test (KHN). Material and Methods: Nineteen enamel specimens were prepared using third human molars. These specimens were fixed on molars of volunteers and were divided into groups: OP38-Opalescence Boost PF38%, PO37-Pola Office 37.5% and CO-Control group. For chemical analysis (n= 3), the dentin layer was removed, keeping only the enamel, which was subjected to acidic digestion by microwave radiation. It was necessary to perform sample dilutions for the elements fluorine (F), calcium (Ca) and phosphorus (P) for quantification using the IC test. The KHN (n= 5) was performed before and after the treatments. Five indentations were made, separated by 100 µm, for each specimen using a load of 25 gf for 5 seconds in the microdurometer. The data were analyzed using ANOVA with a 5% significance level. Results: The OP38 group had the largest concentrations of F, Ca and P ions. The PO37 group showed the lowest concentrations of F and Ca ions. The average KHN was not significantly different between the OP38 and PO37 groups. Conclusion: Enamel whitened with hydrogen peroxide containing fluoride had greater concentrations of F, Ca and P ions. The presence of fluoride in the whitening agent did not influence the enamel microhardness.


2020 ◽  
Vol 11 ◽  
Author(s):  
Rucha Arun Bapat ◽  
Jingtan Su ◽  
Janet Moradian-Oldak

Macromolecular assembly of extracellular enamel matrix proteins (EMPs) is intimately associated with the nucleation, growth, and maturation of highly organized hydroxyapatite crystals giving rise to healthy dental enamel. Although the colocalization of two of the most abundant EMPs amelogenin (Amel) and ameloblastin (Ambn) in molar enamel has been established, the evidence toward their interaction is scarce. We used co-immunoprecipitation (co-IP) to show evidence of direct molecular interactions between recombinant and native Amel and Ambn. Ambn fragments containing Y/F-x-x-Y/L/F-x-Y/F self-assembly motif were isolated from the co-IP column and characterized by mass spectroscopy. We used recombinant Ambn (rAmbn) mutants with deletion of exons 5 and 6 as well as Ambn derived synthetic peptides to demonstrate that Ambn binds to Amel via its previously identified Y/F-x-x-Y/L/F-x-Y/F self-assembly motif at the N-terminus of its exon 5 encoded region. Using an N-terminal specific anti-Ambn antibody, we showed that Ambn N-terminal fragments colocalized with Amel from secretory to maturation stages of enamel formation in a single section of developing mouse incisor, and closely followed mineral patterns in enamel rod interrod architecture. We conclude that Ambn self-assembly motif is involved in its interaction with Amel in solution and that colocalization between the two proteins persists from secretory to maturation stages of amelogenesis. Our in vitro and in situ data support the notion that Amel and Ambn may form heteromolecular assemblies that may perform important physiological roles during enamel formation.


Sign in / Sign up

Export Citation Format

Share Document