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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Effect of Conventional Mouthrinses on Initial Bioadhesion to Enamel and Dentin in situ

Hannig, C., Gaeding, A., Basche, S., Richter, G., Helbig, R., Hannig, M. 04 August 2020 (has links)
Aim: The study aimed to investigate the effect of a customary fluoride solution, containing sodium fluoride and amine fluoride, on initial biofilm formation on enamel and dentin in situ compared directly to chlorhexidine. Methods: Bovine enamel and dentin specimens were mounted on maxillary splints carried by 9 subjects. After 1 min of pellicle formation, rinses with tap water (control), chlorhexidine (meridol med CHX 0.2%, GABA) and a fluoride mouthrinse (elmex, GABA) were performed for 1 min. Subsequently, the slabs were carried for another 8 h. The adherent bacteria were determined by DAPI staining, live-dead staining and determination of colony-forming units after desorption; glucan formation was visualized with concanavalin A. Additionally, energy-dispersive X-ray spectroscopy (EDX) analysis of the in situ biofilm layers was conducted, and contact angle measurements were performed. Statistical evaluation was performed by means of the Kruskal-Wallis test followed by the Mann-Whitney U test (p < 0.05). Results: In the control group, significantly higher amounts of adherent bacteria were detected on dentin (4.8 x 10⁶ ± 5.4 x 10⁶ bacteria/cm²) than on enamel (1.2 x 10⁶ ± 1.5 x 10⁶ bacteria/cm² , DAPI). Chlorhexidine significantly reduced the amount of adherent bacteria (dentin: 2.8 x 10⁵ ± 3.4 x 10⁵ bacteria/cm² ; enamel: 4.2 x 10⁵ ± 8.7 x 10⁵ bacteria/cm²). Rinses with the fluoride solution also significantly reduced bacterial adherence to dentin (8.1 x 10⁵ ± 1.5 x 10⁶ bacteria/cm²). Fluoride could not be detected by EDX analysis of the biofilms. Fluoride mouthrinsing did not influence the wettability of the pellicle-covered enamel surface. Conclusion: In addition to the reduction of demineralization and antibacterial effects, fluorides inhibit initial biofilm formation on dental hard tissues considerably, especially on dentin.
12

Depozice CaF2 ultratenkých vrstev na grafenový substrát / The deposition of CaF2 ultrathin layers on graphene substrate

Caesar, Radek January 2020 (has links)
This master’s thesis is focused on preparation and analysis of ultrathin CaF2 (calcium fluoride) films on a graphene substrate. CaF2 was deposited in UHV conditions at substrate temperatures in the range from 20 °C to 400 °C. The material was deposited on Si(111) with a native SiO2 layer and on a substrate with a CVD graphene layer. The deposited films were analyzed by XPS, AFM and SEM. Moreover four different sample holders for deposition purposes were designed in this work.
13

Nepřímé spektrofotometrické stanovení fluoridů na bázi tvorby komplexů se zirkoniem / Indirect spectrophotometric determination of fluoride on the base of zirconium complexes

Šilerová, Iva January 2011 (has links)
The objective of this study was the calculation and optimalization methods of the indirect spectrophotometric determination of fluoride based on the zirconium complex. Three organic reagent eriochromcyanin R chromazurl S and xylenol orange were tested. As the most sensitive system was shown the complex of zirconium with xylenol orange. Linear standard curve was ranged from 1,5.10-6 to 7,5.10-5 mol.dm-3. H2PO4-, Fe3+ and the highest concentrations of Fe2+, SO42- were tested for interferent. The Fe2+ and SO4- interfere only above the concentration which cannot be found in natural water. The optimized method was applied for the determination of fluoride in the model and real drinking, mineral and surface water.
14

Total Fluoride Intake and Urinary Excretion in German Children Aged 3–6 Years

Haftenberger, Marjolein, Viergutz, Gabriele, Neumeister, Volker, Hetzer, Gisela January 2001 (has links)
There have only been few investigations comparing total fluoride intake and the fluoride proportion excreted in urine in pre–school children. In addition, the results of available studies are conflicting. Total fluoride intake was assessed in 11 healthy children aged 3–6 years on 2 consecutive days and urinary fluoride excretion was determined. The duplicate–diet approach was used for the assessment of fluoride intake from solid and liquid foods. Fluoride intake from toothbrushing was calculated as the difference between the amount of fluoride in the paste put on the toothbrush and the drinking water (fluoride concentration 0.25 mg/l) used for rinsing vs. the fluoride amounts recovered in the toothpaste spat out and in the rinsing water. Use of fluoridated domestic salt and/or fluoride tablets was recorded. The children’s intake of fluoride from food averaged 202.5±116.2 μg F/day. They swallowed an average amount of 273.9±175.6 μg F/day when brushing their teeth. Daily fluoride ingestion from all sources totalled 930.7±391.5 μg or 53.0±21.4 μg/kg body weight. On average 51.5% of the fluoride ingested was excreted in urine. The wide interindividual variation makes it necessary to evaluate the urinary excretion rate for fluoride in larger study populations with varied fluoride exposure. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
15

Tennfluoridtandkräm och plackinducerad gingivit : -En jämförelse mellan tennfluorid och konventionell tandkräm / Stannous fluoride Toothpaste and p laqueinduced gingivitis : A comparison between stannous fluoride and conventional toothpasteA literature study

Josefsson, Rita January 2022 (has links)
Sammanfattning   Syfte: Syftet med denna studie var att undersöka vilken påverkan en stabiliserad tennfluorid tandkräm har avseende gingivit på kort och långsikt jämfört med konventionell fluoridtandkräm. Metod: En allmän litteraturstudie där sökning samt insamling av originalstudier från olika tillförlitliga databaser utfördes på ett systematiskt sätt. Databaserna som användes var CINAHL, DOSS och PubMed. Sökningen och sökorden utgick från litteraturstudiens syfte där urvalet begränsades med inklusions- och exklusionskriterier. Totalt valdes 14 originalstudier, vilka kvalitetsgranskades och presenterades.  Resultat: Utvalda originalstudier delades in i tre olika underrubriker: tennfluoridens effekt på gingivit kortsiktigt och tennfluoridens effekt på gingivit långsiktigt samt tennfluoridens effekt på bakteriefloran som spelar roll vid gingivitförekomsten. Resultatet visar fler fördelar med att använda en tennfluoridtandkräm jämfört med en konventionell fluoridtandkräm avseende patienter med gingivit. Resultatet visar även färre aktiva patogena bakterier i hela munnen vid användning av tennfluoridtandkräm. Slutsats: tandkrämer som innehåller tennfluorid kan ha förebyggande och terapeutiska effekter mot plack och gingivit. Framför allt ger den fler fördelar än en vanlig konventionell fluoridtandkräm i den dagliga munhygienrutinen. Flera studier med större population bör utföras för att säkerställa resultaten och kunna driva rekommendationen via Socialstyrelsens riktlinjer. / Stannous fluoride Toothpaste and plaque-induced gingivitis  -A comparison between stannous fluoride and conventional toothpaste A literature study Summary   Aim: The aim of this study was to investigate the effect of a stabilized stannous fluoride toothpaste on gingivitis in the short and long term compared to conventional sodium fluoride toothpaste. Method: A literature study , the searching and collecting  of articles was performed in a systematic way from specific databases CINAHL, DOSS and PubMed. The search and the keywords were based on the purpose of the study and the selection was according to the inclusion and exclusion criteria. A total of 14 original articles were selected, which were quality reviewed and presented. Results: Selected articles were divided into three different subheadings: the effect of stannous fluoride on gingivitis in the short term, the effects of stannous fluoride on gingivitis in the long term and the effect of stannous fluoride on the bacterial flora that plays a role in the occurrence of gingivitis. The results showed more advantages of using a stannous fluoride toothpaste compared to a conventional fluoride toothpaste for patients with gingivitis. The results also showed less active pathogenic bacteria throughout the mouth when using toothpaste containing stannous fluoride. Conclusion: Toothpastes that contain stannous fluoride can have preventive and therapeutic effects against plaque and gingivitis. Above all, it provides more benefits than a regular conventional sodium fluoride toothpaste in the daily oral hygiene routine. However, future studies with larger population should be carried out to ensure the results and be able to pursue the recommendation via the Swedish National Board of Health and Welfare's guidelines.
16

Direct and indirect effects of different dentifrices on the initial bacterial colonization of enamel in situ overnight

Rosenauer, Tobias, Basche, Sabine, Flemming, Jasmin, Hannig, Christian, König, Belinda, Hannig, Matthias 19 March 2024 (has links)
Objective: The aim of this study was to investigate the direct and indirect influence of fluoridated toothpastes and fluoride-free toothpaste with hydroxyapatite (HAP) as active ingredient on initial bacterial colonization on enamel in situ. Methods: For this clinical-experimental pilot study, eight subjects were instructed to brush their teeth with three different toothpastes (Elmex®: 1400 ppm AmF, Meridol®: 1400 ppm AmF +SnF2, Karex®: HAP), using each for two consecutive days. As a control, brushing without toothpaste was performed. To evaluate bacterial colonization, subject wore splints with buccally placed bovine enamel platelets overnight. Two modes were tested. In a first pass (regimen A), the splints were inserted after toothbrushing to examine the indirect effects of the dentifrices. In order to investigate the direct effects, the specimens were brushed in situ in a second pass (regimen B). Biofilm formation was visualized and quantified using fluorescence microscopy (DAPI and BacLight) and transmission electron microscopy (TEM). Results: For brushing regimen A (indirect effect of dentifrices), no statistical differences were detected between any of the tested dentifrices or the control. Likewise, no statistically significant differences were recorded for brushing regimen B (direct effect of dentifrices). Furthermore, no differences between the different brushing techniques were determined with regard to the ultrastructure of the overnight biofilm. Conclusion: Within the limitations of the present pilot study, it can be concluded that in patients with good oral hygiene, dentifrices and their chemical composition have no statistically significant effect on the initial bacterial colonization of enamel platelets in situ, irrespectively of the mode of application.
17

Evaluation of mechanical and fluoride ion release properties of a resin based restorative material, “Cention”

Hulsart, Line, Hongseethong, Chawanrat January 2022 (has links)
Background: A new permanent dental restorative material, Cention Forte, have recently been introduced. The manufacturer claims that this material has higher compressive strength than glass ionomer as well as positive ion release properties. Aim: To evaluate compressive strength, hardness and fluoride ion release properties of a new resin based dental restauration material, Cention Forte, in comparison with frequently used dental restoration materials.  Methods: Comparisons among Ceram.X Spectra ST (resin composite), GC Fuji II LC (glass ionomer) and Cention Forte (alkasite) were performed. Compression strength, Vickers hardness test and cumulative fluoride ion release for 2 days, 7 days in a pH4 water solution were tested. Results: Resin composites and Cention Forte showed no significant differences in compression strength, while glass ionomers showed a lower compression strength. The Vickers hardness test presented no significant difference between Cention Forte and the other two materials. Significant differences were found among the three materials in fluoride ion release. Resin composites released least amount of fluoride ions compared to Cention Forte and glass ionomer. After 2 days, Cention Forte release less fluoride than glass ionomer, but no differences in fluoride concentration after 7 days between these two materials.  Conclusions: Cention Forte showed equivalent mechanical properties to composite resin and comparable fluoride release property to glass ionomers.
18

Hypervalent diorganoantimony(III) fluorides via diorganoantimony(III) cations – a general method of synthesis

Preda, Ana Maria, Raţ, Ciprian I., Silvestru, Cristian, Lang, Heinrich, Rüffer, Tobias, Mehring, Michael 18 February 2016 (has links) (PDF)
Novel diorganoantimony(III) fluorides containing ligands with pendant arms, R2SbF (5), (R)PhSbF (6) [R = 2-(2′,6′-iPr2C6H3N[double bond, length as m-dash]CH)C6H4], R′′2SbF (7) and (R′′)PhSbF (8) [R′′ = 2-(Me2NCH2)C6H4], were prepared via the ionic derivatives [R2Sb]+[PF6]− (1), [(R)PhSb]+[PF6]− (2), [R′′2Sb]+[SbF6]− (4) and [(R′′)PhSb]+[SbF6]− (obtained in situ) by treatment with [Bu4N]F·3H2O. The ionic species used as starting materials as well as [R′2Sb]+[PF6]− (3) [R′ = 2-(2′,4′,6′-Me3C6H2N[double bond, length as m-dash]CH)C6H4] were obtained from the corresponding bromides or chlorides and Tl[PF6] or Ag[SbF6]. The compounds were investigated by multinuclear NMR spectroscopy in solution, MS and IR spectroscopy in the solid state. The molecular structures of the ionic species 1·2CH2Cl2 and 3·2CHCl3 as well as of the fluorides 5–8 were determined by single-crystal X-ray diffraction. / Dieser Beitrag ist aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
19

Kariesprophylaxe als multifaktorielle Präventionsstrategie

Zimmer, Stefan 19 September 2000 (has links)
Gesundheitspolitische Bestrebungen haben im Bereich der zahnmedizinischen Prophylaxe unter anderem die Förderung der häuslichen Mundhygiene sowie Programme zur Kariesprophylaxe bei Risikogruppen im Rahmen der Gruppenprophylaxe zum Ziel. Daher wurden in zwei Studien unterschiedliche Programme zur Betreuung von Kariesrisikokindern untersucht. In drei weiteren Studien wurde die Wirksamkeit neu entwickelter manueller und elektrischer Zahnbürsten im Rahmen der häuslichen Mundhygiene untersucht. ·Studien zur Betreuung von Kariesrisikokindern a)Ein individualisiertes Programm mit vierteljährlich durchgeführten professionellen Zahnreinigungen und der Anwendung eines niedrig dosierten Fluoridlackes (0,1% Fluorid) zeigte nach zwei Jahren im Vergleich zu einer Kontrollgruppe keinen kariesprophylaktischen Effekt. Die Kinder waren zu Beginn neun Jahre alt. Die Maßnahmen fanden in der Zahnklinik statt. b)Bei Grundschülern ergab eine zweimal jährlich durchgeführte Touchierung der Zähne mit einem Lack mit 2,26% Fluorid eine Kariesreduktion von 37% (p / In these days, politics is aimed at enhancing dental prophylaxis by supporting non professional oral hygiene measures. In addition, special programs are promoted which focus on caries prevention in high risk groups as part of dental group prophylaxis. In two studies, therefore, the effectiveness of different programs for caries risk-children was examined. In three other studies, the effectiveness of newly developed manual and electrical toothbrushes was tested. ·Caries risk studies a)An individualized program with professional toothcleaning and the application of a low dose fluoride varnish (0.1% fluoride) was performed four times a year. After two years of implementation this program did not show a caries preventive effect when compared to a control group. b)In primary school children a high dose fluoride varnish (2.26% fluoride) was applicated two times a year over a period of four years. This was done in the school within the group prophylaxis. This measure resulted in a 37% caries reduction (p
20

Synthesis of Organoaluminum Fluorides and of an Oxo-Centered Trinuclear Carboxylate of Aluminum / Synthese von Organoaluminiumfluoriden und eines Oxo-zentrierten trinuklearen Carboxylates des Aluminiums

Hatop, Hagen 28 June 2001 (has links)
No description available.

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