scholarly journals Mechanical characterization of the enamel microstructure treated with non alcoholic drinks

2021 ◽  
Vol 2 (2) ◽  
pp. 1733-1740
Author(s):  
Lazo Gabriel E. ◽  
Abal Adrián A ◽  
Belloni Federico ◽  
Merlo Diego A ◽  
Barceló Miguel A ◽  
...  
Keyword(s):  
Alcoholic Beverage ◽  
Dental Enamel ◽  
Enamel Microstructure ◽  
Contact Depth ◽  
Dental Crowns ◽  
Internal Zone ◽  
Before And After ◽  
Alcoholic Drinks ◽  
Radial Enamel

In previous studies, it has been shown that the microstructure of prismatic dental enamel presents differences between the external and internal zone. Radial enamel is found in the outer third of enamel and has higher microhardness values than enamel with Hunter- Schreger Bands (HSB) that occupies the inner 2/3. Our aim was to evaluate the mechanical behavior of radial enamel and HSB due the action of a non-alcoholic beverage in vitro. Longitudinal sections of dental crowns were embedded in polymer, worn and polished with sandpapers of decreasing granulation. The samples were immersed in a flavoured natural water for 12 minutes. Nanohardness tests (Triboindenter Hysitron) were performed on the radial and HSB enamel before and after the exposure to the drink. Hardness determinations "H", reduced modulus "Er" and contact depth "hc" were obtained. The percentage of reduction of hardness was determined. The values found in healthy radial enamel were H: 5.48±0.23 GPa; Er: 86.97±8.11 GPa; hc: 149.73±4.25 nm and in HSB H: 4.24±0.43 GPa; Er: 75.24±7.09 GPa; hc: 176.36±11.29 nm. After exposure to beverage, it was found in the radial enamel H: 2.22±0.31 GPa; Er: 58.73±10.79 GPa; hc: 270.29±21.22 nm, and in HSB H: 1.54±0.42 GPa; Er: 48.11±6.54 GPa; hc: 350.10±63.33 nm. After the drink action, the values of hardness of the radial enamel and HSB decreased and the trend observed in healthy enamel remained, where the highest values corresponded to the radial enamel. The percentage reduction of H in the radial enamel was 59.48% and in the HSB enamel it was 63.67%. The contact depth increased by about 50%.The decrease in hardness is related to the mineral loss produced by the acids contained in the drink. We conclude that the action of the non-alcoholic beverage produces a decrease in the mechanical properties in both the radial enamel and the HSB. The lower values in the reduced module Er indicate the formation of a superficial softened layer, the enamel with HSB being more vulnerable.

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
Keyword(s):  
Dental Enamel ◽  
Double Blind ◽  
Fluoride Treatment ◽  
Before And After ◽  
Amine Fluoride ◽  
Knoop Microhardness ◽  
Effect Of Copper ◽  
Removable Appliance

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.

scholarly journals In-Vitro Silanization of Dental Enamel to Prevent Demineralization

2021 ◽  
pp. 353-363
Author(s):  
José R. Gutiérrez-Camacho ◽  
Luis Alejandro Aguilera-Galavíz ◽  
G. Sánchez-Balderas ◽  
Gabriela Palestino ◽  
Norma Verónica Zavala-Alonso ◽  
...  
Keyword(s):  
Citric Acid ◽  
Acidic Medium ◽  
Tooth Enamel ◽  
Dental Enamel ◽  
Hydrophobic Modification ◽  
Dental Tissues ◽  
Before And After ◽  
Topical Fluoride ◽  
Scanning Electron

Introduction. Caries is a multifactorial disease that can negatively affect dental tissues through the demineralization process, which produces acids deriving from the metabolism of carbohydrates. Some strategies to prevent this process have been proposed, such as topical fluoride application, resin-based restorations, pit and fissures sealers, infiltrated resins, vaccines, mouthwashes, and several brushing techniques. Objective. To evaluate in vitro enamel hydrophobic modification as a method of prevention against demineralization. Materials and Methods. A descriptive and comparative study was carried out. Thirty premolars extracted for orthodontic reasons were obtained, encapsulated in epoxy resin, sectioned, and sanded to obtain specimens 3mm in thickness. The samples were pretreated with NaOCl and EDTA, incubated with 1 and 4% octadeyltrichlorosilane (OTS) or with 3 and 6% octadecyltriethoxysilane (TEOS) for 5min and for 8h. Subsequently, the samples were immersed in citric acid for 2 months. The samples were analyzed by their contact angle, infrared spectroscopy, scanning electron microscopy, atomic and confocal force, before and after treatment in citric acid. Results. The samples coated with 1 and 4% OTS for 5min and 8h kept the silanizing agent on their surface after 2 months in citric acid. The treatment with TEOS was only effective at 6% with a reaction time of 5min. Conclusions. The modification with 1 and 4% OTS protects the surface of the tooth enamel from demineralization in acidic medium. The results indicate that treatment with 4% OTS is effective from 5min, which makes it appropriate in clinical practice.

scholarly journals Dental Enamel Microstructure Exposed to Non-Alcoholic Beverages In Vitro

2020 ◽  
Vol 26 (S1) ◽  
pp. 45-46
Author(s):  
A. Tanevitch ◽  
A. Abal ◽  
G. Lazo ◽  
C. Gigena ◽  
M.J. Ingeniero ◽  
...  
Keyword(s):  
Dental Enamel ◽  
Alcoholic Beverages ◽  
Enamel Microstructure

scholarly journals Effect of flavored water on the morphological and chemical composition of human dental enamel microestructure in vitro

2021 ◽  
Vol 2 (2) ◽  
pp. 1724-1732
Author(s):  
Gómez B. Francisco ◽  
Guzmán María P. ◽  
Papasodaro Jimena ◽  
Procopio R. Melina M. ◽  
Saldías Alejandro J. ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Tooth Enamel ◽  
Chemical Elements ◽  
Dental Enamel ◽  
Morphological Description ◽  
Significant Difference ◽  
Before And After ◽  
Flavored Water ◽  
Calcium Phosphorus

There is a remarkable interest in the dental area about the effect produced by the acidic agents contained in commercial non-alcoholic drinks on dental enamel due to their ability to produce caries or erosive lesions. The objective was to characterize the morphological and the chemical alterations of the adamantine structure exposed to the action of a flavored water. Human dental crowns sectioned in the buccolingual direction were embedded in polymer. Flat and highly polished surfaces were obtained by wear with descending granulation sandpaper. Observations and chemical analyses were performed on radial enamel before and after exposure to the beverage, at the ESEM FEI QUANTA 200-EDS (SeMFi-LIMF. FI- UNLP). For the morphological description, the etching patterns of the enamel were considered. The chemical elements sodium, magnesium, chlorine, and the calcium/phosphorus ratio were studied. The samples were immersed in 100 ml of a flavored water for 12 minutes. At the ESEM, the prisms presented different patterns of acid etching, which may affect the core or the profile. The chemical composition showed variations according to the area, before and after the treatment. Although the studied elements were present in the healthy enamel, both in the radial and in the Hunter Schreger bands, the percentage values were different. In the bands, sodium and magnesium increased while chlorine decreased. After the action of the flavored water, sodium and magnesium increased even more and the chlorine dropped markedly. A significant difference was found in Ca/P ratio before and after treatment. The beverage used contains acid agents in its composition that produce loss of minerals from the adamantine tissue. We conclude that the exposure of tooth enamel to flavored water produces demineralization compatible with erosion lesions.    

scholarly journals Analysis of Dental Enamel Surface Submitted to Fruit Juice Plus Soymilk by Micro X-Ray Fluorescence:In VitroStudy

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Janaína Salmos Brito ◽  
Alexandrino Santos Neto ◽  
Luciano Silva ◽  
Rebeca Menezes ◽  
Natália Araújo ◽  
...  
Keyword(s):  
Fruit Juice ◽  
Ph Value ◽  
Dental Enamel ◽  
Dental Erosion ◽  
Fruit Juices ◽  
Initial Time ◽  
X Ray ◽  
Before And After ◽  
Knoop Microhardness

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.

SEM Evaluation of Fluoride Pretreatment Effects on Acid-Etching of Caries-Like Enamel Lesions In Vitro

1981 ◽  
Vol 39 ◽  
pp. 474-475
Author(s):  
M. John Hicks
Keyword(s):  
Dental Enamel ◽  
Preventive Measure ◽  
Acid Etching ◽  
Distilled Water ◽  
Adhesive Resin ◽  
Fluoride Treatment ◽  
Treatment Groups ◽  
Pretreatment Effects ◽  
Preparation Techniques

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.

Electron microscopic study of the membrane glycoproteins in the rat kidney after cisplatin treatment

1989 ◽  
Vol 47 ◽  
pp. 912-913
Author(s):  
S.K. Aggarwal
Keyword(s):  
Alkaline Phosphatase ◽  
Rat Kidney ◽  
Light And Electron Microscopy ◽  
Kidney Tissue ◽  
Membrane Glycoproteins ◽  
Electron Microscopic ◽  
Before And After ◽  
Interstrand Cross Links ◽  
Cross Links

The proposed primary mechanism of action of the anticancer drug cisplatin (Cis-DDP) is through its interaction with DNA, mostly through DNA intrastrand cross-links or DNA interstrand cross-links. DNA repair mechanisms can circumvent this arrest thus permitting replication and transcription to proceed. Various membrane transport enzymes have also been demonstrated to be effected by cisplatin. Glycoprotein alkaline phosphatase was looked at in the proximal tubule cells before and after cisplatin both in vivo and in vitro for its inactivation or its removal from the membrane using light and electron microscopy.Outbred male Swiss Webster (Crl: (WI) BR) rats weighing 150-250g were given ip injections of cisplatin (7mg/kg). Animals were killed on day 3 and day 5. Thick slices (20-50.um) of kidney tissue from treated and untreated animals were fixed in 1% buffered glutaraldehyde and 1% formaldehyde (0.05 M cacodylate buffer, pH 7.3) for 30 min at 4°C. Alkaline phosphatase activity and carbohydrates were demonstrated according to methods described earlier.

Structural integrity after cold storage of human epidermal model in hypothermosol: A correlative ultrastructural and fluorescent assay

1994 ◽  
Vol 52 ◽  
pp. 270-271
Author(s):  
Henry H. Eichelberger ◽  
John G. Baust ◽  
Robert G. Van Buskirk
Keyword(s):  
Cold Storage ◽  
Structural Integrity ◽  
Culture Media ◽  
Cell Structure ◽  
Natural State ◽  
Sodium Cacodylate ◽  
Ruthenium Tetroxide ◽  
Cacodylate Buffer ◽  
Before And After

For research in cell differentiation and in vitro toxicology it is essential to provide a natural state of cell structure as a benchmark for interpreting results. Hypothermosol (Cryomedical Sciences, Rockville, MD) has proven useful in insuring the viability of synthetic human epidermis during cold-storage and in maintaining the epidermis’ ability to continue to differentiate following warming.Human epidermal equivalent, EpiDerm (MatTek Corporation, Ashland, MA) consisting of fully differentiated stratified human epidermal cells were grown on a microporous membrane. EpiDerm samples were fixed before and after cold-storage (4°C) for 5 days in Hypothermosol or skin culture media (MatTek Corporation) and allowed to recover for 7 days at 37°C. EpiDerm samples were fixed 1 hour in 2.5% glutaraldehyde in sodium cacodylate buffer (pH 7.2). A secondary fixation with 0.2% ruthenium tetroxide (Polysciences, Inc., Warrington, PA) in sodium cacodylate was carried out for 3 hours at 4°C. Other samples were similarly fixed, but with 1% Osmium tetroxide in place of ruthenium tetroxide. Samples were dehydrated through a graded acetone series, infiltrated with Spurrs resin (Polysciences Inc.) and polymerized at 70°C.

Inhibitory effects of bioaccessible anthocyanins and procyanidins from apple, red grape, cinnamon on α-amylase, α-glucosidase and lipase

2020 ◽  
pp. 1-9
Author(s):  
Pınar Ercan ◽  
Sedef Nehir El
Keyword(s):  
Inhibitory Activity ◽  
Digestive Enzymes ◽  
Positive Control ◽  
Anthocyanin Content ◽  
Inhibitory Effects ◽  
Total Anthocyanin ◽  
Total Anthocyanin Content ◽  
Before And After ◽  
Red Grape

Abstract. The goals of this study were to determine and evaluate the bioaccessibility of total anthocyanin and procyanidin in apple (Amasya, Malus communis), red grape (Papazkarası, Vitis vinifera) and cinnamon (Cassia, Cinnamomum) using an in vitro static digestion system based on human gastrointestinal physiologically relevant conditions. Also, in vitro inhibitory effects of these foods on lipid (lipase) and carbohydrate digestive enzymes (α-amylase and α-glucosidase) were performed with before and after digested samples using acarbose and methylumbelliferyl oleate (4MUO) as the positive control. While the highest total anthocyanin content was found in red grape (164 ± 2.51 mg/100 g), the highest procyanidin content was found in cinnamon (6432 ± 177.31 mg/100 g) (p < 0.05). The anthocyanin bioaccessibilities were found as 10.2 ± 1%, 8.23 ± 0.64%, and 8.73 ± 0.70% in apple, red grape, and cinnamon, respectively. The procyanidin bioaccessibilities of apple, red grape, and cinnamon were found as 17.57 ± 0.71%, 14.08 ± 0.74% and 18.75 ± 1.49%, respectively. The analyzed apple, red grape and cinnamon showed the inhibitory activity against α-glucosidase (IC50 544 ± 21.94, 445 ± 15.67, 1592 ± 17.58 μg/mL, respectively), α-amylase (IC50 38.4 ± 7.26, 56.1 ± 3.60, 3.54 ± 0.86 μg/mL, respectively), and lipase (IC50 52.7 ± 2.05, 581 ± 54.14, 49.6 ± 2.72 μg/mL), respectively. According to our results apple, red grape and cinnamon have potential to inhibit of lipase, α-amylase and α-glucosidase digestive enzymes.

Radiolabeled r-Hirudin as a Measure of Thrombin Activity at, or within, the Rabbit Aorta Wall In Vitro and In Vivo

1994 ◽  
Vol 71 (04) ◽  
pp. 499-506 ◽  
Author(s):  
Mark W C Hatton ◽  
Bonnie Ross-Ouellet
Keyword(s):  
Rabbit Aorta ◽  
Balloon Injury ◽  
Recombinant Hirudin ◽  
Aorta Wall ◽  
Thrombin Activity ◽  
Before And After ◽  
The Matrix

SummaryThe behavior of 125I-labeled recombinant hirudin towards the uninjured and de-endothelialized rabbit aorta wall has been studied in vitro and in vivo to determine its usefulness as an indicator of thrombin activity associated with the aorta wall. Thrombin adsorbed to either sulfopropyl-Sephadex or heparin-Sepharose bound >95% of 125I-r-hirudin and the complex remained bound to the matrix. Binding of 125I-r-hirudin to the exposed aorta subendothelium (intima-media) in vitro was increased substantially if the tissue was pre-treated with thrombin; the quantity of l25I-r-hirudin bound to the de-endothelialized intima-media (i.e. balloon-injured in vitro) correlated positively with the quantity of bound 131I-thrombin (p <0.01). Aortas balloon-injured in vivo were measured for thrombin release from, and binding of 125I-r-hirudin to, the de-endothelialized intimal surface in vitro; 125I-r-hirudin binding correlated with the amount of active thrombin released (p <0.001). Uptake of 125I-r-hirudin by the aorta wall in vivo was proportional to the uptake of 131I-fibrinogen (as an indicator of thrombin activity) before and after balloon injury. After 30 min in the circulation, specific 125I-r-hirudin binding to the uninjured and de-endo- thelialized (at 1.5 h after injury) aorta wall was equivalent to 3.4 (± 2.5) and 25.6 (±18.1) fmol of thrombin/cm2 of intima-media, respectively. Possibly, only hirudin-accessible, glycosaminoglycan-bound thrombin is measured in this way.

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