scholarly journals Effect of Tannic Acid on the Protective Properties of the in situ Formed Pellicle

2016 ◽  
Vol 51 (1) ◽  
pp. 34-45 ◽  
Author(s):  
Susann Hertel ◽  
Sandra Pötschke ◽  
Sabine Basche ◽  
Judith Delius ◽  
Wiebke Hoth-Hannig ◽  
...  
Keyword(s):  
Tannic Acid ◽  
Ex Vivo ◽  
Oral Exposure ◽  
Dependent Manner ◽  
Pellicle Formation ◽  
Protective Properties ◽  
Transmission Electron ◽  
Bovine Enamel ◽  
The Impact

Objectives: In the present in situ/ex vivo study the impact of tannic acid on the erosion-protective properties of the enamel pellicle was tested. Additionally, the antiadherent and antibacterial effects of tannic acid were evaluated. Methods: The pellicle was formed in situ on bovine enamel samples fixed on individual splints worn by 6 subjects. Following 1 min of pellicle formation the volunteers rinsed for 10 min with tannic acid. After further oral exposure for 19 min, 109 min, and 8 h overnight, respectively, slabs were incubated in HCl ex vivo (pH 2.0, 2.3, 3.0) over 120 s. Subsequently, kinetics of calcium and phosphate release were measured photometrically. Samples after a 1-min fluoride mouth rinse as well as enamel samples with and without a 30-min in situ pellicle served as controls. Antiadherent effects were evaluated after a 1-min rinse with tannic acid and oral exposure of the slabs overnight. DAPI (4′,6-diamidino-2-phenylindole) combined with concanavalin A staining and live/dead staining was used for fluorescence microscopic visualization and quantification of adherent bacteria and glucans. Modification of the pellicle's ultrastructure by tannic acid was evaluated by transmission electron microscopy (TEM). Results: Tannic acid significantly improved the erosion-protective properties of the pellicle in a pH-dependent manner. Bacterial adherence and glucan formation on enamel were significantly reduced after rinses with tannic acid as investigated by fluorescence microscopy. TEM imaging indicated that rinsing with tannic acid yielded a sustainable modification of the pellicle; it was distinctly more electron dense. Conclusion: Tannic acid offers an effective and sustainable approach for the prevention of caries and erosion.

scholarly journals Enzymology and Ultrastructure of the in situ Pellicle in Caries-Active and Caries-Inactive Patients

2017 ◽  
Vol 51 (2) ◽  
pp. 109-118 ◽  
Author(s):  
Jasmin Kirsch ◽  
Christian Hannig ◽  
Sandra Pötschke ◽  
Sabine Basche ◽  
William H. Bowen ◽  
...  
Keyword(s):  
Exposure Time ◽  
Enzyme Activities ◽  
Fluorescence Labeling ◽  
Oral Exposure ◽  
Pellicle Formation ◽  
Caries Activity ◽  
Transmission Electron ◽  
High Uniformity ◽  
The Impact

Aim: The present study aimed to evaluate the impact of caries activity on the key enzymes and the ultrastructure of the in situ pellicle. Methods: Pellicle formation was performed on bovine enamel slabs. Intraoral exposure (3, 30, and 120 min) was accomplished by 14 caries-active (DMFS: 22.7 ± 12.1) and 13 caries-inactive (DMFS: 1.5 ± 1.8) individuals. The enzyme activities (lysozyme, peroxidase, α-amylase, glycosyltransferase [GTF]) in the in situ pellicle and resting saliva of all participants were analyzed directly after oral exposure. In addition, a simultaneous visualization of these enzymes, extracellular glucans, and adherent bacteria was carried out. Fluorescent patterns were analyzed with fluorescence labeling and 4′,6-diamidino-2-phenylindole/concanavalin A staining. In addition, the distribution of GTF B, C, and D and the ultrastructure of the pellicle were examined by gold immunolabeling and transmission electron microscopy with selected samples. Results: Enzyme activities of amylase, peroxidase, lysozyme, and GTF were detected on all enamel slabs in an active conformation. Neither exposure time nor caries activity had an impact on the enzyme activities. Gold immunolabeling indicated that the pellicle of caries-active subjects tends to more GTF D molecules. The pellicles of caries-inactive and -active individuals revealed a similar ultrastructural pattern. Conclusion: The enzyme activities as well as the pellicle's ultrastructure are of high similarity in caries-active and -inactive subjects. Thereby, oral exposure time has no significant influence. This reflects a high uniformity during the initial phase of bioadhesion (3-120 min) concerning enzymatic functions. However, there is a tendency towards more GTF D in caries-active individuals.

scholarly journals Influence of Calcium Phosphate and Apatite Containing Products on Enamel Erosion

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
A. Kensche ◽  
S. Pötschke ◽  
C. Hannig ◽  
G. Richter ◽  
W. Hoth-Hannig ◽  
...  
Keyword(s):  
Oral Cavity ◽  
Oral Exposure ◽  
Ion Release ◽  
Pellicle Formation ◽  
Protective Properties ◽  
Ph Values ◽  
Mineral Components ◽  
Tooth Mousse ◽  
Bovine Enamel

For the purpose of erosion prevention the present study aimed to compare the efficacy of two biomimetic products and a fluoride solution to optimize the protective properties of the pellicle. After 1 min ofin situpellicle formation on bovine enamel slabs, 8 subjects adopted CPP-ACP (GC Tooth Mousse), a mouthwash with hydroxyapatite microclusters (Biorepair), or a fluoride based mouthwash (elmex Kariesschutz) for 1 min each. Afterwards, samples were exposed in the oral cavity for 28 min. Native enamel slabs and slabs exposed to the oral cavity for 30 min without any rinse served as controls. After oral exposure, slabs were incubated in HCl (pH values 2, 2.3, and 3) for 120 s and kinetics of calcium and phosphate release were measured photometrically; representative samples were evaluated by SEM and TEM. The physiological pellicle reduced demineralization at all pH values; the protective effect was enhanced by fluoride. The biomimetic materials also reduced ion release but their effect was less pronounced. SEM indicated no layer formation after use of the different products. However, TEM confirmed the potential accumulation of mineral components at the pellicle surface. The tested products improve the protective properties of thein situpellicle but not as effectively as fluorides.

scholarly journals Application of Plant Extracts for the Prevention of Dental Erosion: An in situ/in vitro Study

2015 ◽  
Vol 49 (5) ◽  
pp. 477-487 ◽  
Author(s):  
Marie-Theres Weber ◽  
Matthias Hannig ◽  
Sandra Pötschke ◽  
Franziska Höhne ◽  
Christian Hannig
Keyword(s):  
Plant Extracts ◽  
Dental Erosion ◽  
Oral Exposure ◽  
Wild Form ◽  
Dependent Manner ◽  
Mouth Rinse ◽  
Protective Properties ◽  
The Impact

Objectives: Antiadherent and antibacterial effects of certain plant extracts have been proven to be beneficial in preventive dentistry. In the present in situ/in vitro crossover study, the impact of plant extracts rich in polyphenols on the erosion-protective properties of the in situ pellicle was evaluated. Methods: Individual splints were prepared for 12 subjects for intraoral exposure of bovine enamel specimens. Following formation of a 1-min pellicle, watery plant extracts (leaves of the wild form of Ribes nigrum, the wild form of Origanum as well as a combination of both) were administered for 10 min in situ. Alternatively, a mouth rinse with fluorides (Elmex Kariesschutz) was performed for 1 min. After further oral exposure for 19/28 min, respectively, slabs were removed and incubated with HCl in vitro over 120 s (pH 2, 2.3, 3). The resulting calcium and phosphate release was quantified photometrically. Slabs with and without a 30-min in situ pellicle served as controls. The modification of pellicle ultrastructure was evaluated by transmission electron microscopy (TEM). Results: Plant extracts modulated the erosion-protective properties of the native in situ pellicle in all test groups in a pH-dependent manner. The combination of R. nigrum leaves and Origanum enhanced the protective properties of the pellicle at all pH values; the administration of this preparation was comparable, yet superior, to the effect of the fluoridated mouth rinse. TEM images indicated that rinsing with R. nigrum leaves/Origanum yielded a distinctly thicker and more electron-dense pellicle. Conclusion: The combination of certain plant extracts offers a novel approach to the complementary prevention of dental erosion.

scholarly journals Influence of Erosive and Abrasive Cycling on Bonding of Different Adhesive Systems to Enamel: An In situ Study

2016 ◽  
Vol 27 (5) ◽  
pp. 548-555 ◽  
Author(s):  
Marina Ciccone Giacomini ◽  
◽  
Leslie Caroll Casas-Apayco ◽  
Camila Moreira Machado ◽  
Maria Cristina Carvalho de Almendra Freitas ◽  
...  
Keyword(s):  
Bond Strength ◽  
Orange Juice ◽  
Failure Modes ◽  
Ex Vivo ◽  
Adhesive Systems ◽  
Digital Microscope ◽  
Bonding Systems ◽  
Bovine Enamel ◽  
The Impact

Abstract This study evaluated the impact of orange juice on the bond strength (BS) of dentin bonding systems (DBSs) to enamel surface after simulation with an in situ/ ex vivo erosive cycling. One hundred and ninety two bovine enamel fragments (4x4x2mm) were obtained and randomized regarding superficial microhardness and distributed to palatal devices for 8 volunteers, in three phases (one for each DBS), containing 8 blocks, which were, allocated in 4 pairs. Daily, these pairs were subjected extraorally to the following conditions: CONT- neither erosive nor abrasive challenge; ERO- erosive challenge only; ABR- abrasive challenge only and ERO + ABR- with erosive and abrasive challenges. Erosive cycles (immersion in orange juice, 3 times/day/5 min/5 days) or/and abrasive challenges (electric toothbrush, 3 times/day/1 min/5 days) were performed. After these cycles, all specimens were restored with the adhesive systems Adper Scotchbond Multi Purpose (MP), Adper Single Bond 2 (SB) or Clearfil SE Bond (SE), and the composite resin Filtek Z250. After 7 days, sticks (area ≅1 mm2) were obtained and subjected to the microtensile bond strength test (μTBS) at 0.5 mm/min. Data was statistically analyzed by ANOVA and Tukey tests (a=0.05). Failure modes were determined using a digital microscope (40´). DBS was the only statistical significant factor. SE was the unique DBS not affected in any challenge, whereas MP and SB performed according to the scenario. The adhesive and mixed failures were predominant in all groups. Overall performance suggested that BS to enamel after erosive /abrasive challenged by orange juice was not affected and it was material-dependent.

scholarly journals Evaluation of Anti-Biofilm Activity of Mouthrinses Containing Tannic Acid or Chitosan on Dentin In Situ

Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1351
Author(s):  
Anton Schestakow ◽  
Moritz S. Guth ◽  
Tobias A. Eisenmenger ◽  
Matthias Hannig
Keyword(s):  
Electron Microscopy ◽  
Tannic Acid ◽  
Biofilm Formation ◽  
Antibacterial Effect ◽  
Positive Control ◽  
Dependent Manner ◽  
Antibacterial Effects ◽  
Oral Biofilm ◽  
Transmission Electron

In contrast to enamel, dentin surfaces have been rarely used as substrates for studies evaluating the effects of experimental rinsing solutions on oral biofilm formation. The aim of the present in situ study was to investigate the effects of tannic acid and chitosan on 48-h biofilm formation on dentin surfaces. Biofilm was formed intraorally on dentin specimens, while six subjects rinsed with experimental solutions containing tannic acid, chitosan and water as negative or chlorhexidine as positive control. After 48 h of biofilm formation, specimens were evaluated for biofilm coverage and for viability of bacteria by fluorescence and scanning electron microscopy. In addition, saliva samples were collected after rinsing and analyzed by fluorescence (five subjects) and transmission electron microscopy (two subjects) in order to investigate the antibacterial effect on bacteria in a planktonic state and to visualize effects of the rinsing agents on salivary proteins. After rinsing with water, dentin specimens were covered by a multiple-layered biofilm with predominantly vital bacteria. In contrast, chlorhexidine led to dentin surfaces covered only by few and avital bacteria. By rinsing with tannic acid both strong anti-adherent and antibacterial effects were observed, but the effects declined in a time-dependent manner. Transmission electron micrographs of salivary samples indicated that aggregation of proteins and bacteria might explain the antiadhesion effects of tannic acid. Chitosan showed antibacterial effects on bacteria in saliva, while biofilm viability was only slightly reduced and no effects on bacterial adherence on dentin were observed, despite proteins being aggregated in saliva after rinsing with chitosan. Tannic acid is a promising anti-biofilm agent even on dentin surfaces, while rinsing with chitosan could not sufficiently prevent biofilm formation on dentin.

A Study of Membrane Impact on Spatial Resolution of Liquid In Situ Transmission Electron Microscope

2020 ◽  
Vol 26 (1) ◽  
pp. 126-133
Author(s):  
Ming Li ◽  
Ruth Knibbe
Keyword(s):  
Electron Microscope ◽  
Spatial Resolution ◽  
Transmission Electron Microscope ◽  
Signal To Noise Ratio ◽  
Chromatic Aberration ◽  
Membrane Thickness ◽  
Additional Material ◽  
Transmission Electron ◽  
The Impact

AbstractMicrochip technology with electron transparent membranes is a key component for in situ liquid transmission electron microscope (TEM) characterization. The membranes can significantly influence the TEM imaging spatial resolution, not only due to introducing additional material layers but also due to the associated bulging. The membrane bulging is largely defined by the membrane materials, thickness, and short dimension. The impact of the membrane on the spatial resolution, especially the extent of its bulging, was systematically investigated through the impact on the signal-to-noise ratio, chromatic aberration, and beam broadening. The optimization of the membrane parameters is the key component when designing the in situ TEM liquid cell. The optimal membrane thickness of 50 nm was found which balances the impact of membrane bulging and membrane thickness. Beyond this, the short membrane window dimension and the chip nominal spacing should be minimized. However, these two parameters have practical limitations in regards to chip handling.

scholarly journals Intranasal Niosomal In Situ Gel as a Promising Approach for Enhancing Flibanserin Bioavailability and Brain Delivery: In Vitro Optimization and Ex Vivo/In Vivo Evaluation

Pharmaceutics ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 485 ◽  
Author(s):  
Usama A. Fahmy ◽  
Shaimaa M. Badr-Eldin ◽  
Osama A. A. Ahmed ◽  
Hibah M. Aldawsari ◽  
Singkome Tima ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Oral Treatment ◽  
Drug Dissolution ◽  
Nasal Administration ◽  
Brain Delivery ◽  
Drug Bioavailability ◽  
In Vivo Evaluation ◽  
In Situ Gel ◽  
The Impact

Flibanserin (FLB) is a multifunctional serotonergic agent that was recently approved by the FDA for the oral treatment of premenopausal women with hypoactive sexual desire disorder. FLB is a centrally acting drug that has a low oral bioavailability of 33% owing to its exposure to the hepatic first-pass effect, as well as its pH-dependent solubility, which could be an obstacle hindering the drug dissolution and absorption via mucosal barriers. Thus, this work aimed at overcoming the aforementioned drawbacks and promoting the nose-to-brain delivery of FLB via the formulation of an intra-nasal in situ niosomal gel. The Box–Behnken design was employed to study the impact of Span® 85 concentration (X1), hydration time (X2), and pH of the hydrating buffer (X3) on the vesicle size and drug entrapment. The optimized formulation exhibited a spherical shape with a vesicular size of 46.35 nm and entrapment efficiency of 92.48%. The optimized FLB niosomes integrated into gellan gum-based in situ gel exhibited enhanced ex vivo permeation and improved plasma and brain concentrations after nasal administration in rats compared to raw FLB. These findings highlight the capability of the proposed intra-nasal FLB niosomal in situ gel to boost the drug bioavailability and to promote its direct delivery to the brain.

scholarly journals Effects of Experimental Agents Containing Tannic Acid or Chitosan on the Bacterial Biofilm Formation in Situ

Biomolecules ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1315
Author(s):  
Anton Schestakow ◽  
Matthias Hannig
Keyword(s):  
Hydrochloric Acid ◽  
Tannic Acid ◽  
Biofilm Formation ◽  
Antibacterial Properties ◽  
Positive Control ◽  
Bacterial Biofilm ◽  
Dental Biofilm ◽  
Acid Ph ◽  
Bovine Enamel

Chitosan and tannic acid are known for their antibacterial properties. In the present in-situ study, their antibacterial and anti-adherent effects on biofilm formation on enamel were investigated. Six subjects carried upper jaw splints with bovine enamel specimens, allowing in-situ biofilm formation. During the two-day trial, subjects rinsed with experimental solutions that contained either chitosan, tannic acid (pH = 2.5), tannic acid (pH = 7) or hydrochloric acid. Water served as the negative and chlorhexidine as the positive control. Rinsing occurred four or five times following two different rinsing protocols to investigate both the immediate and long-lasting effects. After 48 h of intraoral exposure, the dental plaque was stained with LIVE/DEAD® BacLight, and fluorescence micrographs were evaluated by using the software ImageJ. The results were verified by scanning electron microscopy. Rinsing with chitosan resulted in little immediate antibacterial and anti-adherent effects but failed to show any long-lasting effect, while rinsing with tannic acid resulted in strong immediate and long-lasting effects. Except for a slightly lower antibacterial effect, the neutral solution of tannic acid was as good as the acidic solution. Hydrochloric acid showed neither an antibacterial nor an anti-adherent effect on dental biofilm formation. Experimental solutions containing tannic acid are promising anti-biofilm agents, irrespective of the pH values of the solutions. Chitosan, on the other hand, was not able to prevent biofilm formation.

scholarly journals Adhesion of Hydroxyapatite Nanoparticles to Dental Materials under Oral Conditions

Scanning ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12 ◽  
Author(s):  
Cíntia Mirela Guimarães Nobre ◽  
Norbert Pütz ◽  
Matthias Hannig
Keyword(s):  
Electron Microscopy ◽  
Dental Materials ◽  
Hydroxyapatite Nanoparticles ◽  
Pellicle Formation ◽  
Transmission Electron ◽  
Different Shapes ◽  
Oral Conditions ◽  
Dental Applications

Hydroxyapatite nanoparticles (nano-HAP) are receiving considerable attention for dental applications, and their adhesion to enamel is well established. However, there are no reports concerning the effects of HAP on other dental materials, and most of the studies in this field are based on in vitro designs, neglecting the salivary pellicle-apatite interactions. Thus, this in situ pilot study aims to evaluate the effects of three hydroxyapatite-based solutions and their interactions with different dental material surfaces under oral conditions. Hence, two volunteers carried intraoral splints with mounted samples from enamel and from three dental materials: titanium, ceramics, and polymethyl-methacrylate (PMMA). Three HAP watery solutions (5%) were prepared with different shapes and sizes of nano-HAP (HAP I, HAP II, HAP III). After 3 min of pellicle formation, 10 ml rinse was performed during 30 sec. Rinsing with water served as control. Samples were accessed immediately after rinsing, 30 min and 2 h after rinsing. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to characterize the particles, and SEM evaluated the pellicle-HAP interactions. SEM and TEM results showed a high variation in the size range of the particles applied. A heterogeneous HAP layer was present after 2 h on enamel, titanium, ceramics, and PMMA surfaces under oral conditions. Bridge-like structures were visible between the nano-HAP and the pellicle formed on enamel, titanium, and PMMA surfaces. In conclusion, nano-HAP can adhere not only to enamel but also to artificial dental surfaces under oral conditions. The experiment showed that the acquired pellicle act as a bridge between the nano-HAP and the materials’ surface.

Stratified Ion Damage and in Situ Regrowth in GaAs/AlAs Heterostructures

1990 ◽  
Vol 201 ◽  
Author(s):  
A G Cullis ◽  
D J Eaglesham ◽  
D C Jacobson ◽  
J M Poate ◽  
C R Whitehouse ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Point Defects ◽  
Multilayer Structures ◽  
Dependent Manner ◽  
Characteristic Boundary ◽  
Transmission Electron ◽  
Wide Range ◽  
Ion Damage ◽  
Lattice Damage

AbstractThe material-dependent manner in which ion damage occurs in AlAs/GaAs heteroepitaxial structures is demonstrated using conventional and high resolution transmission electron microscopy. Both 150keV and 2MeV Si+ ion implants are employed over a wide range of ion doses. Under conditions which yield rapid build-up of lattice damage in GaAs, the AlAs is found to be relatively resistant to structure breakdown. Indeed, the crystalline AlAs exerts a novel protective effect on immediately adjacent regions of the GaAs layers. For high implantation doses amorphous-crystal superlattices are formed in multilayer structures. For the highest ion doses the AlAs lattice begins to be disrupted by a characteristic, boundary-dependent, heterogeneous mechanism. These observations suggest that mobile point defects play a significant role in AlAs in situ restructuring processes.

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