Дисертації з теми "Glass enamel"

Objectives: This research aimed to characterise the physico-chemical interaction of bioactive glass 45S5 (BAG) air-abrasion with human enamel including the controlled and selective removal of substrates and the remineralisation of enamel white spot lesions (WSLs). Materials and methods: The effect of six operating parameters on air-abrasion dynamic cutting efficiency/patterns was assessed using an enamel analogue material (MacorTM) and white light profilometry. Standardised resin composite restorations created within MacorTM blocks, were removed in simulated clinical conditions and scanned using triangulation laser profilometry to investigate the effect of operating parameters on the selective resin composite removal using BAG air-abrasion. The remineralisation of artificial enamel WSLs treated using BAG mixtures were evaluated using Raman micro-spectroscopy, microhardness and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectrometry (EDX). The physical and optical changes in WSLs pre-conditioned using air-abrasion with BAG-polyacrylic acid (PAA-BAG) powder were detected using non-contact profilometry and optical coherence tomography (OCT). All comparisons were considered statistically significant if p < 0.05. Results: Significant differences in air-abrasion cutting efficiency / pattern were observed according to the tested parameters. BAG air-abrasion removed resin composite more selectively than conventional alumina air-abrasion and the effect of altering the unit’s operating parameters was significant. Enamel WSLs treated with BAG mixtures exhibited a significantly higher Knoop microhardness compared to the negative control. Raman micro-spectroscopy detected significantly higher phosphate content and the SEM images revealed mineral depositions on the surface of treated lesions. Pre-conditioning WSL surfaces with PAA-BAG air-abrasion increased WSL surface area. This pre-treatment increased Knoop microhardness and the mineral content of remineralised WSLs. Conclusions: The ultraconservative clinical applications of BAG air-abrasion can be improved by altering the operating parameters. BAG and PAA-BAG can remineralise enamel WSLs. Pre-conditioning the lesion surface with PAA-BAG air-abrasion modifies the lesion surface physically and consequently enhances remineralisation using BAG 45S5 therapy.

Magister Scientiae Dentium - MSc(Dent)
Introduction: Micro-leakage and enamel demineralization is still a major challenge in dental practice. It can lead to formation of demineralization lesions around and beneath the adhesive–enamel interface (Mali et al., 2006). Enamel demineralization adjacent to orthodontic brackets is one of the risks associated with orthodontic treatment. The prevention of demineralization during orthodontic treatment is therefore essential for aesthetic reasons and to circumvent the onset of caries. Aim: To assess micro-leakage and enamel demineralization around orthodontic direct attachments (brackets) using three different orthodontic cements. Materials and methods: In this in-vitro study, intact (non carious) extracted human premolars were used to compare the micro-leakage and enamel demineralization of three different cements (Fuji Ortho LC, Rely X luting 2 and Transbond XT). The dye penetration technique was used to evaluate micro-leakage on extracted human premolars. Micro-hardness testing was performed on 21 teeth to determine enamel demineralization. Sixty teeth were randomly divided into 3 groups of twenty teeth each. Direct attachments were cemented on each tooth using 3 different cements; Fuji Ortho LC (GC Fuji II LC GC Corporation Tokyo, Japan), (group 1), Rely X luting 2 cement (3M ESPE dental product, USA), (group 2), Transbond XT Light Cure (3M Unitek, Monrovia, Calif), (group 3). After the orthodontic direct attachments were fitted, they were exposed to 500 thermo-cycles between 5°C and 55°C, with a dwell time of 15 seconds in a buffered (pH 7) 1% methylene blue dye solution (Grobler et al, 2007). The specimens were viewed under a stereomicroscope (Nikon, Japan) at magnification of 40 times. Photographs of each specimen were taken with a Leica camera (Leica DFC 290 micro-systems, Germany) fitted onto a stereomicroscope. The ACDsee photo editing programme was used to transfer the photographs to a computer to measure the dye penetration along the enamel–adhesive and adhesive–bracket interfaces, both on the gingival and occlusal edge at × 40 magnification. For the demineralization sample, 21 teeth were divided into 3 groups of seven teeth each, where direct attachments were cemented using each of the 3 cements, group 1, Fuji Ortho LC (GC Fuji II LC GC Corporation Tokyo, Japan); group 2, Rely X luting 2 cement (3M ESPE dental product, USA) and group 3, Transbond XT Light Cure (3M Unitek, Monrovia, Calif). A digital hardness tester with Vickers diamond indenter (Zwick RoellIndentec (ZHV; Indentec UK) was used to measure surface micro-hardness of enamel before and after attaching the brackets. Ten indentations were made on the enamel surface of each tooth before bonding the brackets with a 300g load applied for 15 seconds to establish the baseline hardness value. After de-bonding the brackets, the hardness was measured again in the same area as mentioned above to determine the degree of enamel demineralization (softening). Result: The result showed statistically significantly lower levels of micro-leakage for Transbond XT (P= <0.001). The amount of micro-leakage on the margins was significantly higher in the gingival portion (P <0.05) as compared with the occlusal margin. Enamel micro-hardness tests before bonding using the three different cements showed that the variances are not significantly different (Chi-squared = 3.051, df = 2, p-value = 0.218). However, the micro-hardness tests done after bonding and thermo-cycling was statistically significantly different (Chi-squared = 13.435, df = 2, p-value = 0.001). Clearly, the Transbond XT group had less hardness, implying greater demineralization than the Fuji Ortho LC and Rely X luting 2 groups. Two sample t-tests show that mean value for the Fuji Ortho and Rely X luting 2 were not significantly different from each other (t = -0.636, df = 12, p-value = 0.537). The mean value for Transbond XT differed significantly from both the other two means: Transbond XT vs Fuji Ortho LC (t = 3.249, df = 6.9, p-value = 0.014). Transbond XT vs Rely X luting 2 (t = 3.493, df = 6.8, p-value = 0.011). Conclusions: This study showed that Fuji Ortho LC and Rely X luting 2 show more micro-leakage than Transbond XT. However Transbond XT had significant lower micro-leakage, less hardness (greater demineralization) than the Fuji Ortho LC and Rely X luting 2. This may have been due to the fluoride release which significantly reduces demineralization. Therefore the Fuji Ortho LC and Rely X luting 2 may be recommended for prevention of demineralization during orthodontic treatment.

Enamel demineralisation or white spot lesions (WSLs) is a risk for all patients undergoing fixed appliance orthodontic treatment (FAOT) with no consensus with regards to prevalence, risk factors, prevention and treatment. Slow-release fluoride glass devices (SRFGDs) have been shown to clinically prevent caries without relying on patient’s compliance, therefore their effectiveness in preventing WSLs during FAOT was investigated. An in-vitro exploratory study investigated fluoride (F) and phosphate (PO4) release from different types of powder from SRFGDs incorporated into a composite resin bonding material. Samples were stored in artificial saliva and assessed with ion chromatography for up to six months. Three types of powder showed high F release to maximise caries prevention and low PO4 release to minimise degradation of powder. A questionnaire was emailed to orthodontists’ members of the British Orthodontic Society. For majority of responders the key factors to the problems related to WSLs are clinical examination, photographs, F, oral hygiene, diet and duration of FAOT. A double-blind, randomised clinical study with orthodontic patients randomly allocated to SRFGDs or placebo devices threaded onto the orthodontic wire was conducted. Cross-polarised digital photographs of the maxillary permanent central and lateral incisors and canines were taken for 63 subjects at the start and for 40 subjects at the end of the study. One examiner assessed photographs for presence and severity of WSLs. Majority of volunteers and the smallest number of refusals lived in the most deprived areas according to the Multiple Deprivation Index. Use of SRFGDs would decrease severity by preventing 2.88 times more teeth compared to use of 225 ppm F mouth-rinse once daily and 1,450 ppmF tooth-paste twice daily. Duration of FAOT and increased gingival index at the start of FAOT increased significantly the risk of developing WSLs. SRFGDs were effective in preventing teeth with WSLs during the course of FAOT.

Enamel damage and demineralisation are common complications associated with fixed orthodontic appliances. In particular, the clean-up of adhesive remnants after debonding is a recognised cause of enamel damage. Furthermore, fixed attachments offer retentive areas for accumulation of cariogenic bacteria leading to enamel demineralisation and formation of white spot lesions (WSLs). Bioactive glasses may be used to remove adhesives, preserving the integrity of the enamel surface, while also having the potential to induce enamel remineralisation, although their efficacy in both respects has received little attention. A systematic review evaluating the remineralisation potential of bioactive glasses was first undertaken. No prospective clinical studies were identified; however, a range of in vitro studies with heterogeneous designs were identified, largely providing encouraging results. A series of glasses was prepared with molar compositions similar to 45S5 (SylcTM; proprietary bioactive glass) but with constant fluoride, reduced silica and increased sodium and phosphate contents. These glasses were characterised in several tests and the most promising selected. This was designed with hardness lower than that of enamel and higher than orthodontic adhesives. Its effectiveness in terms of removal of composite- and glass ionomer- based orthodontic adhesives was evaluated against SylcTM and a tungsten carbide (TC) bur. This novel glass was subsequently used for remineralisation of artificially-induced orthodontic WSLs on extracted human teeth. The novel glass propelled via the air-abrasion system selectively removed adhesives without inducing tangible physical enamel damage compared to SylcTM and the conventional TC bur. It also remineralised WSLs with surface roughness and intensity of light backscattering similar to sound enamel. In addition, mineral deposits were detected on remineralised enamel surfaces; these acted as a protective layer on the enamel surface and improved its hardness. This layer was rich in calcium, phosphate, and fluoride; 19F MAS-NMR, confirmed the formation of fluorapatite. This is particularly beneficial since fluorapatite is more chemically stable than hydroxyapatite and has more resistance to acid attack. Hence, a promising bioactive glass has been developed.

Emaillierte Scheiben finden seit sehr langer Zeit ihre Anwendung im Bauwesen als opake Fassadenpaneele in System- oder vorgehängten, hinterlüfteten Fassaden. Mit Mustern in Form von Punkten, Streifen oder Quadraten wird ein teilweiser Sonnen- beziehungsweise Blendschutz realisiert. Ebenso ist seit langem eine festigkeitsmindernde Wirkung einer solchen Bedruckung auf Glasbauteilen bekannt. Die Gründe dafür sind nicht geklärt, und es existieren mehrere Erklärungsversuche, die ihre Belastbarkeit aber noch nicht bewiesen haben. Ebenso beruhen die Normangaben zu bedruckten, vorgespannten Glasprodukten auf empirischen Untersuchungen ohne weitere wissenschaftliche Basis. Daher wird in dieser Arbeit das Ziel verfolgt, eine in der Fachliteratur genannte mögliche Ursache der Festigkeitsminderung genauer zu untersuchen. Neben einer Bewertung der bereits vorhandenen, wenigen Erklärungsversuche wird die in der Literatur geäußerte und auch durch Versuche im Rahmen von Qualitätskontrollen der Glasveredler berechtigte Annahme der Festigkeitsminderung auf Grund geänderter Temperaturverhältnisse während des Abkühlvorgangs durch die Emailleschicht besonders untersucht. Dieser Annahme wird mit spannungsoptischen Messmethoden und in Bruchversuchen nachgegangen. Mit Streulichtmessungen werden mögliche Veränderungen im Eigenspannungsverlauf über die Glasdicke quantitativ ermittelt. Mit Bruchversuchen in einem modifizierten Doppelring-Biegeversuch können dann unter Ansatz der ermittelten Vorspannung im Glas Rückschlüsse auf mögliche strukturelle Veränderungen der Glasoberfläche beziehungsweise größere Defekte geschlossen werden. Mittels numerischer Simulationen des Vorspannprozesses von bedruckten und unbedruckten Scheiben kann auch die Auswirkung verschiedener thermischer Ausdehnungskoeffizienten genauer bestimmt werden. In praktischen Versuchen kann eine solche mögliche Auswirkung nicht untersucht werden, da die Emaille als Überzugsmaterial als handelsübliches Produkt verwendet und nicht frei konfektioniert wird. Daher können nur die thermischen Ausdehnungskoeffizienten im Versuch berücksichtigt werden, die sich im handelsüblichen Produkt einstellen.

Aim: To investigate the use of fluoride glass slow-release devices (FGSRD) for the prevention of dental erosion of human dental enamel in vitro. Methods: Human teeth (permanent and primary) were used for this study. Enamel slabs were randomly allocated to four study groups: Group 1: 24 permanent enamel slabs with FGSRD, Group 2: 24 permanent enamel slabs with placebo non-FGSRD, Group 3: 20 primary enamel slabs with FGSRD, Group 4: 20 primary enamel slabs with placebo non-FGSRD. The glass slow-release devices were randomised into two groups. Test and placebo groups were coded until the end of the study. The enamel slabs were dipped in a citric acid solution for two minutes five times daily for 28 days and brushed twice a day. This was to create the erosive environment for this in vitro study. The slabs were kept in artificial saliva and stored in an incubator at 37°C. The glass slow-release devices (fluoride and non-fluoride) were present in all containers. The surface profile was measured at baseline using surface profilometry and after 14 and 28 days of the cycling regime. Analysis: Simple t-tests were used to compare the permanent and primary teeth groups with 0.05 as the significance level and an ANOVA t-test with a Bonferroni correction to compare: primary and permanent teeth. Daily fluoride release of the FGSRD’s was measured. Results: For enamel of primary teeth, after 14 days 40% less erosion was observed in the F group which decreased to 31% at the end of the study period, i.e., 28 days. This was highly statistically significant (p < 0.001) at both time points. For permanent enamel, no significant differences were observed (p=0.091). Conclusion: FGSRD’s have great potential for protection of primary human enamel against erosive challenge in addition to a number of other uses.

L’art du verre à la Renaissance était marqué par l’influence des maîtres vénitiens, à l’origine d’un certain nombre d’innovations techniques et stylistiques qui connurent un grand succès dans toute l’Europe. En France, Henri II et Catherine de Médicis firent appel à des verriers vénitiens pour établir une verrerie à proximité du château royal de Saint-Germain-en-Laye. Près de trente ans plus tard, une autre équipe de verriers italiens, cette fois-ci originaire du village d’Altare, fondèrent une verrerie au faubourg Saint-Germain-des-Prés. Le développement de l’industrie verrière en Île-de-France du début du règne de Henri II en 1547 à la fin du règne de Henri IV en 1610 est donc étroitement lié à l’arrivée de verriers italiens qui apportèrent leur style et leur savoir-faire. L’histoire verrière de la région ne se limite cependant pas à l’influence italienne. Deux métiers du verre s’organisèrent à Paris à cette époque : celui des patenôtriers d’émail et de verre et celui des marchands verriers. L’étude des hommes et de leurs compétences a constitué un premier axe de recherche. Le second axe choisi a consisté à étudier la commercialisation et la diffusion des produits de verre en Île-de-France et leur contexte d’utilisation. Le verre prit en effet, au XVIe siècle, une place plus importante sur les tables des Parisiens modestes ou fortunés. Les propriétés de ce matériau particulier étaient adaptées à un certain nombre d’usages. Les verres de la Renaissance se divisaient alors entre verres fonctionnels et verres plus prestigieux, collectionnés pour leur valeur esthétique et décorative. Cette thèse transdisciplinaire s’inscrit dans les domaines de l’histoire, de la culture matérielle, de l’histoire de l’art et des techniques et de l’archéologie
The European Renaissance glass art was deeply influenced by the style and the techniques invented by Venetian glassmakers. Those fashionable glass products were in demand in every European country. In France, king Henri II and queen Catherine de Medici established a glasshouse near the royal palace of Saint-Germain-en-Laye and employed Venetian glassmakers. After the death of the glassworkers, a new glasshouse, ruled by Italian glassmakers from Altare was established at the end of the 16th century, in the faubourg Saint-Germain-des-Prés. The development of the glass industry in Île-de-France from 1547 to 1610 is linked to the style and techniques brought by Italian glassmakers. In addition to the Italian influence, two glass-related professions were created at that time in Paris: the glass bead makers and the glass sellers. The study of men and their skills constitutes one approach of the subject. The second one explores the trade, circulation and uses of glass products. They became, in the 16th century, more and more common in both modest and wealthy Parisian interiors and were used for their particular properties (especially suitable for medical use for example). On the other hand, some glass products, more prestigious and fashionable, were collected for their decorative and aesthetic value

Este estudo in situ avaliou em esmalte bovino desmineralizado, submetido ou não a um desafio cariogênico, os efeitos de um cimento de ionômero de vidro de alta viscosidade (CIVav) e de um selante resinoso, comparativamente a um controle (sem selamento). Doze voluntários usaram dispositivos intrabucais palatinos (DIP) contendo 12 blocos de esmalte bovino desmineralizado, fixados dois a dois para simular uma fissura em V, a qual foi selada com um dos materiais: CIVav (Ketac, Molar Easymix), selante resinoso (Delton) ou controle (sem selamento). Metade dos espécimes foi submetida ao acúmulo de biofilme, recebendo oito aplicações diárias de sacarose a 20% para provocar um desafio cariogênico, além de outras três, de solução de dentifrício fluoretado (1 g : 3 mL), enquanto a outra metade não sofreu acúmulo de biofilme, mas também recebeu o dentifrício. Após 14 dias, foram avaliadas as concentrações de flúor no biofilme e no esmalte, bem como o conteúdo mineral (microdureza em secção longitudinal). Os dados obtidos foram analisados estatisticamente ('alfa'= 5%). O teste Friedman ANOVA revelou que a concentração de flúor no biofilme foi estatisticamente maior com o uso do CIVav, em comparação ao selante resinoso e ao controle. A ANOVA e o teste de Tukey constataram que houve maior concentração de flúor no esmalte associado ao CIVav, sobretudo na ausência de desafio cariogênico, enquanto o selante resinoso e controle foram semelhantes. Em relação ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram diferenças entre os grupos na camada mais superficial do esmalte. Com desafio cariogênico, o conteúdo mineral foi sempre maior no esmalte associado ao CIVav do que naquele associado ao selante resinoso, sendo que o controle apresentou resultados intermediários. Sem o desafio cariogênico, houve uma tendência de um maior conteúdo mineral no grupo controle. Os resultados sugerem que o CIVav, aplicado sobre uma superfície desmineralizada e sob desafio cariogênico, demonstrou um potencial cariostático pela sua capacidade de doar flúor à estrutura e ao biofilme dentários, minimizando os efeitos da desmineralização, mas não melhorou a remineralização.
This in situ study evaluated on demineralized bovine enamel, submitted or not to a cariogenic challenge (dental biofilm), the effects of a high viscosity glass ionomer cement (HV-GIC) and a resin sealant in comparison with a control group (without sealing). Twelve volunteers wore a palatal appliance containing 12 blocks of demineralized bovine enamel mounted (2 by 2) to simulate a fissure in a V shape and sealed with: HV-GIC (Ketac? Molar Easymix), resin sealant (Delton) or maintained with no sealing material (control). Half of specimens was submitted to a cariogenic challenge by dripping a 20% sucrose solution 8 times/day besides a fluoride dentifrice solution (1 g : 3 mL) 3 times/day. The others specimens only received a dentifrice solution. After 14 days, the concentration of fluoride in dental biofilm and enamel was evaluated as well as the mineral content (cross-sectional microhardness) of the enamel. The concentration of fluoride in dental biofilm was higher with HV-GIC (Friedman ANOVA, p<0.05) in comparison with resin sealant and control group. The concentration of loosely-bound fluoride on enamel was significant (ANOVA and Tukey test, p< 0.05) specially without a cariogenic challenge for HVGIC, while it was similar for the resin sealant and control group. Concerning the mineral content, ANOVA and Tukey test (p<0.05) detected differences among the groups on the superficial layers of the enamel. Under the dental biofilm influence the mineral content was always higher on the enamel associated with HV-GIC than with resin sealant and the control group presented intermediary results. Without dental biofilm the control group presented a tendency of a higher mineral content. The results suggest that HV-GIC applied on a demineralized surface and under the dental biofilm influence has shown a cariostatic potential by its ability to give fluoride to the dental structure and biofilm reducing the demineralization effects.

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів, Державний вищий навчальний заклад "Український державний хіміко-технологічний університет", Національний технічний університет "Харківський політехнічний інститут", Харків, 2020. Дисертацію присвячено розвитку наукових основ технології екологічно безпечних захисно-декоративних склоемалевих покриттів широкої колірної гами по сталі і кольоровим металам, а також принципів регулювання та прогнозування їх колірних характеристик. Внаслідок проведення дослідження за темою дисертаційної роботи одержані такі наукові результати: - науково обгрунтовано та експериментально доведено, що отримання на кольорових металах емалевих покриттів, які не вміщують Плюмбум, можливе на основі стекол системи Na₂O–BaO–B₂O₃–SiO₂; за комплексом визначених властивостей та здатності утворювати найбільш якісні покриття на мідній основі виділена область базової системи, мол.%: Na₂O – 24,2–40,5; ВаО – 5,0–10,0; B₂O₃ – 15,2–30,5; SiO₂ – 24,0–53,5, яка у зрівнянні з межами цих компонентів в відомих складах безплюмбатних емалей характеризується збільшеним в 2 рази вмістом B₂O₃ і відносно невеликим вмістом SiO₂; - встановлені основні тенденції зміни колірного тону стекол системи Na₂O–BaO–B₂O₃–SiO₂, які суттєво відрізняються за хімічним складом та забарвлені іонними барвниками, з огляду на розташування максимумів ІЧ-спектрів стекол та їх кислотно-основні властивості; останні оцінювались двома розрахунковими структурними параметрами: fSi – ступінь зв’язності кремнекисневого каркасу і Ψв – орієнтовний показник координаційного стану Бору в структурі скла. Доведено, що між колірним тоном λ та Ψв існує значний кореляційний зв'язок для стекол, забарвлених CuO r*=−0,83 і CoO r*=−0,87 та слабкий – для стекол, забарвлених K₂Cr₂O₇ – r*=0,5; - виявлені закономірності забарвлення одної скломатриці і емалевого покриття на її основі в системі R₂O–ВаО–ZnO–Al₂O₃–В₂О₃–TiO₂–SiO₂ рядом іонними барвників. Незалежно від вмісту барвників, вони надають однаковий колірний тон як стеклам, так і покриттям на основі цих стекол, а саме: CuO (1,0–3,0 мас.%) λ=489–494 нм (синьо-зелений), Fe₂O₃ (0,5–2 мас.%) λ=575–585 нм (жовтий), K₂Cr₂O₇ (0,5–2,0 мас.%) λ=570–576 нм (жовто-зелений), CoO (0,5–1,0 мас.%) λ=441–463 нм (синьо-фіолетовий), NiO (0,5–1,0 мас.%) λскла=559′–571′ нм, λпокриттів=598–629 нм (коричневий). Доказано, що за ступенем інтенсивності забарвлення стекол та покриттів на їх основі барвники розташовуються в наступній послідовності: CoO > NiO > CuO > K₂Cr₂O₇ > Fe₂O₃; - вперше встановлений механізм глушіння прозорого матричного емалевого скла в системі R₂O–ВаО–ZnO–TiO₂–Al₂O₃–В₂О₃–TiO₂–SiO₂ при введені МоО3, в результаті якого виникає явище опалесценції, а саме: за рахунок дифракції при розповсюдженні хвиль в мікронеоднорідному середовищі, в якому розмір часток молібден(VI) оксиду (0,05–0,15 мкм) менше довжини хвиль білого світла; - вперше встановлена залежність коефіцієнта дифузного відбиття емалевих покриттів від хімічного складу емалевих фрит, яка отримана обробкою експериментальної вибірки 471 складу покривних емалевих фрит методом множинного кореляційного аналізу і представлена у вигляді математичної моделі, що дозволяє розрахувати хімічний склад покривних емалей із заданим КДВ; коефіцієнт кореляції між експериментальними і розрахунковими значеннями – 0,98; - використовуючи ідею про введенні в будь-який матеріал (скло, пігмент, ситал, метал) певних компонентів в незначній кількості для модифікації його властивостей, вперше виявлено наступне: «малий додаток» Fe₂O₃ у кількості 0,25 мас.% в складі безплюмбатних емалевих стекол на основі базової системи Na₂O–BaO–B₂O₃–SiO₂ і 1 мас.% в складі безфлуористих склоемалей на основі базової системи Na₂O–B₂O₃–SiO₂ активізує процеси лікваційного розшарування скла, що дозволяє збільшити в 1,5–2,5 рази інтенсивність глушіння покриттів, а також покращити оптико-колірні характеристики пігментнозабарвлених склопокриттів, зокрема, червоного кольору. «Малий додаток» ZrO₂ у кількості до 1 мас.% в складі малофлуористої титанової емалі сприяє активному виділенню анатазу в покритті під час випалу та покращенню його оптичних характеристик; - за допомогою розробленої спеціальної комп’ютерної програми COLOUR GLASS, яка автоматично розраховує координати кольорності x y, колірний тон λ, чистоту кольору Р та наносить колірні характеристики матеріалів на графік МКО, вперше доказано, що за картиною розташування точок кольору, по-перше, можна робити прогнози відносно рівноваги, яка утворюється між іонними забарвлюючими комплексами під час варки скла, по-друге, про колористичні можливості суміши пігментів - вперше в області технологій, які потребують підвищених температур, встановлені залежності координат кольору емалевих покриттів від складу суміші пігментів у вигляді поліноміальних математичних моделей, що дозволило вирішити складну матеріалознавчу колористичну проблему знаходження співвідношення пігментів для відтворення кольору зразка із заданими колірними характеристиками. Практичне значення отриманих результатів: - розроблено склади емалевих стекол для кольорових металів, які не містять Плюмбуму – одного із самих шкідливих для навколишнього середовища елемента, запропоновано основи технології одержання виробів з їх використанням. Нові емалі широкої палітри кольорів, різного ступеню прозорості створено на основі матричної прозорої емалі. Вони характеризуються однаковим інтервалом випалу 780–820 °С, у зв’язку з чим спрощується технологія отримання художніх і ювелірних виробів. Емалі пройшли випробування та рекомендовані до впровадження у виробництво з виготовлення художніх виробів в майстерні, що знаходиться в структурі Музею українського живопису (м. Дніпро), а також на підприємстві з виготовлення ювелірних виробів, компанія "Diadema", м. Вінниця. Палітра емалевих покриттів та вироби з них представлені під час доповіді на 24 Міжнародному Конгресі емальєрів в м. Чикаго у 2018 р. Згідно міжнародного договору між ДВНЗ УДХТУ та компанією "Richemont International SA Varinor SA" м. Делемонт, Щвейцарія, виготовлено і передано замовнику емалеві стекла у вигляді порошку і емальовані мідні зразки; - створено каталог зразків кольорів, в якому представлено склооснови, кількість барвників, глушників, відновників та оптико-колірні характеристики емалевих покриттів, що не містять Плюмбум. Назву кольорів встановлювали у відповідності із назвою кольорів системи RAL. Палітра розроблених емалей ювелірного та художнього призначення включає 54 кольори: жовто-червоні, синьо-зелені, оливково-гірчичні, пастельні та коричнево-чорні; - розроблено склади малофлуористих білих і світлозабарвлених титанових емалей, безфлуористої склооснови для отримання яскравозабарвлених емалевих покриттів пігментним способом, які випробувані в виробничих умовах ТОВ «Новомосковський посуд» і рекомендовані до серійного впровадження на заводах з випуску емальованих виробів господарчо-побутового призначення. Технологічні особливості виробництва запропонованих емалей дозволяють здійснювати високотемпературні операції варки емалей на 100 °С, а випалу покриттів – на 30–50 °С нижче відомих, що в епоху тотальної економії топливно-енергетичних ресурсів дуже актуально. Малофлуористі світлозабарвлені кремова і сіро-блакитна емалі впроваджені на ТОВ "Новомосковський посуд"; - вперше для технології емалевих покриттів на сталі розроблено метод колірного моделювання, завдяки якому побудовано колірний трикутник-номограму для виробничої склооснови і пігментів жовтого, червоного, синього, за допомогою якого задається необхідний колір і розраховується необхідне співвідношення пігментів. Метод колірного моделювання є універсальним і може бути застосованим до широкого асортименту силікатних матеріалів: глазуровані покриття на керамічній основі, кольорові будівельні матеріали та інші. У вступі обґрунтовано актуальність теми дисертації, сформульовано головну мету та завдання роботи, представлено наукову новизну та практичну цінність одержаних результатів. В першому розділі наведено аналіз патентної та науково-технічної літератури, що стосується отримання екологічно безпечних емалей широкої колірної гами, сучасного стану виробництва кольорових емалей та контролю їх колірних показників, механізмів забарвлення скла та емалей і факторів, що впливають на формування кольору. У другому розділі надано основні поняття та визначення, які використовуються в роботі, а також методики дослідження фізико-хімічних властивостей і структури стекол, покриттів та їх колірні характеристики. В третьому розділі представлено дослідження з розробки екологічно безпечних емалей для міді та прогнозування їх колірних характеристик. В четвертому розділі представлено результати досліджень з розробки легкоплавкої титанової емалі, яка відповідала б вимогам діючих стандартів та випалювалась в ресурсо- та енергозберігаючих умовах виробництва та була максимально екологічно безпечною для навколишнього середовища. П'ятий розділ присвячений дослідженням з розробки складів емалевих фрит, що не вміщують Флуор, які використовуються для отримання яскравозабарвлених емалевих покриттів для виробів господарчо-побутового призначення. В шостому розділі представлені результати розробки методу колірного моделювання. Відтворити, а тим більше спрогнозувати колір із заданими колірними характеристиками – надзвичайно складна багатопланова матеріалознавча проблема, навіть якщо відома рецептура скла і покриття, режими їх варки та випалу. В сьомому розділі надано результати промислової апробації, реалізації та впровадження отриманих матеріалів.
Thesis for a Doctor of Science Degree in Specialty 05.17.11 – Refractory Non-Metallic Materials Technology, State Higher Educational Institution "Ukrainian State University of Chemical Technology", National Technical University "Kharkiv Polytechnic Institute", Kharkiv, 2019. The dissertation is devoted to creation of physicochemical bases of technology of ecologically safe protective and decorative glass-enamel coatings of wide color scale on steel and non-ferrous metals, development of principles of regulation and prediction of their color. As a result of the research on the topic of dissertation the following scientific results were obtained: - scientifically substantiated and experimentally proved that the production of lead-free enamel coatings on non-ferrous metals is possible on the basis of the Na₂O – BaO – B₂O₃ – SiO₂ glasses, by the complex of defined properties and the ability to form the highest quality coatings on a copper basis the selected region of the base system, mol %: Na₂O – 24,2–40,5; BaO – 5.0–10.0; B₂O₃ – 15.2–30.5; SiO₂ – 24,0–53,5, which in comparison with the limits of these components in known compositions of lead-free enamels, is characterized by a 2-fold increase in the content of B2O3 and a relatively small content of SiO₂; - the basic tendencies of color change of glasses of Na₂O–BaO–B₂O₃–SiO₂ system has been established, which differ significantly in chemical composition and has colored by ionic dyes, taking into account the structural features of glasses and their acid-basic properties. They has been evaluated by two calculated structural parameters: fSi is the degree of connectivity of the silica framework and Ψв is an indicative index of the coordination state of Boron in the structure of the glass. It had proved that there is a significant correlation between the colors λ and Ψv had proved for glasses colored CuO r * = - 0,83 and CoO r * = - 0,87 and weak – for glasses colored K₂Cr₂O₇, -r * = 0,5; - the patterns of coloring of one glass matrix and enamel coatings on its basis in the system R₂O–BaO–ZnO–Al₂O₃–B₂O₃–TiO₂–SiO₂ by a series of ionic dyes has been founded. Regardless of the content of the dyes, they give the same color tone to the glass and coatings based on these glasses, namely: CuO (1.0–3.0 wt%) λ = 489–494 nm (blue-green), Fe₂O₃ (0.5–2 wt%) λ = 575–585 nm (yellow), K₂Cr₂O₇ (0,5–2.0 wt%) λ = 570–576 nm (yellow-green), CoO (0.5–1.0 wt%) λ = 441–463 nm (blue-violet), NiO (0, 5-1.0 wt.%) λ glass = 559′ – 571 nm, λ coatings = 598–629 nm (brown). It has been proved that in the degree of color intensity of glasses and coatings based on them, the dyes has been arranged in the following sequence: CoO> NiO> CuO> K₂Cr₂O₇ > Fe₂O₃; - for the first time, the mechanism of silencing of transparent matrix enamel glass in R₂O–BaO–ZnO–TiO₂–Al₂O₃–B₂O₃–TiO₂–SiO₂ system with the introduction of MoO₃ has been established, which results in the phenomenon of opalescence, namely: due to diffraction at propagation of waves in micro inhomogeneous medium in which the particle size of molybdenum (VI) oxide is 0.05-0.15 μm less than the wavelength of white light; - for the first time, the dependence of the diffuse reflection coefficient (CDR) of enamel coatings on the chemical composition of enamel frits, obtained by processing the experimental sample 471 of the enamel frit composition by multiple correlation analysis, which is presented in the form of a mathematical model that allows you to calculate the chemical composition of the enamel coatings with a given CDR; the correlation coefficient between experimental and calculated values is 0.98; - using the idea of introducing into any material (glass, pigment, sitall, metal) certain components in a small amount to modify its properties, the following has been first discovered: "small addition" of Fe₂O₃ in the amount of 0.25 wt.% in the composition of lead-free enamel glasses based on the base system Na₂O–BaO–B₂O₃–SiO₂ and 1 wt.% in the composition of fluorless glass enamels based on the basic system Na₂O–B₂O₃–SiO₂ activates the processes of differentiation of the segregation-dropping structure of glass, which allows to increase the intensity of opaque coatings by 1.5–2.5 times, as well as to improve the optical-color characteristics of pigment-colored glass coatings, in particular, red. "Small addition" of ZrO₂ in the amount up to 1 wt.% in the composition of low-fluoride titanium enamel promotes the active release of anatase in the coating during firing and improving its optical characteristics; -with the help of a dedicated COLOR GLASS computer program that automatically calculates color coordinates x y, color tone λ, color purity P, and maps the color characteristics of materials to the СIE graph, it has been first demonstrated that the picture of the location of the color points, first, you can make predictions about the equilibrium that is formed between the ionic coloring complexes during the melting of glass, and secondly, about the color potential of the pigment mixture. - for the first time in the field of technologies requiring high temperatures, the dependences of the color coordinates of the enamel coatings on the composition of the pigment mixture in the form of polynomial mathematical models has been established, which made it possible to solve the complex material-coloristic problem of finding the ratio of pigments to reproduce the color of the sample with the specified color characteristics. The practical significance of the obtained results: - the compositions of enamel glasses for non-ferrous metals, which do not contain Plumbum - one of the most harmful for the environment element, had been developed; the basics of technology of obtaining products with their use had offered. New enamels of a wide range of colors with varying degrees of transparency had been created on the basis of matrix transparent enamel and they had characterized by the same firing interval of 780-820 °C, which makes the technology of obtaining artistic and jewelry easier. Enamels had been tested and recommended for implementation in the production of artistic products in the workshop, which locates in the structure of the Museum of Ukrainian Painting (Dnipro), as well as at the jewelry company, Diadema, Vinnytsia. The enamel coatings palette and their products had presented during a report at the 24th International Congress of Enamels in Chicago in 2018. According to an international agreement between the Ukrainian State University of Chemical Technology (Dnipro) and Richemont International SA Varinor SA, Delmont, Switzerland, enamel glass powder and enameled copper samples had been made and handed over to the customer; - a catalog of color samples, which presents the glass base, the number of dyes, opacifiers, reducing agents and the optic-color characteristics of enamel coatings which do not contain Plumbum, has been created. The color name was set in accordance with the color name of the RAL system. The palette of designed enamels of jewelry and artistic purpose includes transparent matrix enamel and 53 colors: yellow-red, blue-green, olive-mustard, pastel and brown-black; - a series of compositions of white and light-colored titanium enamels containing reduced amount of Fluorine, has been developed, also the composition of fluorless frites to obtain brightly colored enamel coatings pigmented way of color, which were fused and passed extensive testing in production conditions factories for the production of enameled household products, has been synthesized. Technological features of production of the enamels offered permits to carry out high-temperature operations of melting at 100oC below the known ones, and firing of coatings – by 30-50 °C, which is very relevant in the era of total saving of fuel and energy resources. Low-fluoride light-colored cream and gray-blue enamels has been introduced at "Novomoskovsk dishes"; - for the first time for the technology of enamel coatings on steel, a method of color modeling has been developed, through which a color triangle-nomogram has been constructed for the production glass base and pigments of yellow, red, blue, by which the required color is specified and the necessary ratio of pigments is calculated. The color modeling method is versatile and can be applied to a wide range of silicate materials: glazed ceramic coatings, colored building materials, and more. The introduction substantiates the relevance of the dissertation topic, formulates the main purpose and objectives of the work, presents the scientific novelty and practical value of the obtained results. The first section provides an analysis of the patent and scientific and technical literature concerning the production of environmentally safe enamels of a wide color range, the current state of production of colored enamels and the control of their color indices, the mechanisms of color of glass and enamels and factors affecting color formation. The second section provides the basic concepts and definitions used in the work, as well as methods for investigating the physicochemical properties and structure of glasses and coatings and their color characteristics. The third section presents studies on the development of environmentally safe enamels for copper and the prediction of their color characteristics. The fourth section presents the results of research on the development of fusible titanium enamel which would meet the requirements of current standards and be burned in resource- and energy-efficient production conditions and be the most environmentally safe for the environment. The fifth section is devoted to the research on the development of enamel frits that do not contain Fluorine and used to produce brightly colored enamel coatings for household products. The sixth section presents the results of the development the color modeling method. Reproduce, and even more so predict, color with predetermined color characteristics is an extremely complex multifaceted material science problem, even if glass and coating formulations, modes of melting and firing are known. In the seventh section the results of industrial testing, realization and implementation of the received materials has been presented.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Introdução: O objetivo deste estudo clínico controlado, prospectivo, randomizado e com avaliadores cegos foi avaliar o desempenho clínico de restaurações cervicais não cariosas frente às diferentes estratégias de adesão ao substrato dental. Métodos: foram utilizados um sistema restaurador adesivo (Single Bond Universal/Z350XT) com e sem condicionamento seletivo do esmalte e um cimento de ionômero de vidro modificado por resina (Vitremer) com e sem tratamento prévio com EDTA, seguindo as instruções do CONSORT. Um total de 200 restaurações foram realizadas por dois operadores em 50 pacientes voluntários. Previamente à execução das restaurações e em cada tempo de avaliação foram avaliados os índices de sangramento gengival, placa visível e CPOD. Todas as restaurações foram avaliadas por meio do sistema de avaliação do USPHS modificado. Dois examinadores calibrados, cegos e diferentes dos operadores realizaram as avaliações nos seguintes intervalos de tempo: inicial imediato (baseline), 6, 12 e 24 meses. Ao final de 24 meses os dados foram analisados pelos testes estatísticos de Friedman, Qui-quadrado, Kappa, Cochran, Wilcoxon e análise de regressão logística múltipla, adotando-se nível de significância a 5%. Resultados: a amostra foi composta de 34 homens e 16 mulheres com idade média de 61,8 anos. Em relação ao CPOD, houve um aumento gradativo e significante ao longo do tempo, havendo diferença entre os quatro tempos de avaliação (p≤0,001). Não teve diferença entre os tempos para o índice de placa visível (p=0,28). No entanto, houve uma redução significativa do índice de sangramento gengival entre o baseline e os demais tempos (p≤0,001). Não houve diferença estatisticamente significante entre os 4 grupos em cada tempo de avaliação em nenhum dos critérios avaliados (p>0,05), assim como não houve entre os 4 tempos de avaliação para todos os grupos (p>0,05). Em relação à regressão logística, embora não tenha apresentado nenhuma variável isolada como estatisticamente significante, o modelo como um todo apresentou-se estatisticamente significante (p=0,034). Conclusão: As quatro diferentes estratégias de adesão em restaurações cervicais não cariosas apresentaram similar desempenho clínico após 24 meses de acompanhamento.
Introduction: the aim of this study, prospective, randomized controlled clinical trial and with blind evaluators was to evaluate the clinical performance of non-carious cervical restorations to different strategies of adhesion for the dental substrate. Methods: we used a restorative adhesive system (Universal/Z350XT Single Bond) with and without selective etching of enamel and a modified glass ionomer luting cement for resin (Vitremer) with and without previous treatment with EDTA, following the instructions of the CONSORT. 200 in total restorations were performed by two operators in 50 patients. Prior to the execution of the restorations and each time, we evaluated the evaluation indexes of gum bleeding, visibly Board and CPOD. All restorations were evaluated using the evaluation system USPHS modified. Two calibrated examiners, blind and different operators, performed the evaluations in the following time intervals: immediate initial (baseline), 6, 12 e 24 months. At the end of 24 months data were analyzed by statistical tests Friedman, Qui-quadrado, Kappa, Cochran, Wilcoxon and multiple logistic regression analysis, adopting the significance level 5%. Results: the sample was composed of 34 men and 16 women with an average age of 61.8 years. Concerning the CPOD, there was a gradual and significant increase over time, difference between the four evaluation times (p≤0,001). There was no difference between the time the visible card index (p=0,28). However, there was a significant reduction of gingival bleeding index between the baseline and other times (p≤0,001). There was no statistically significant difference among the 4 groups in each time any of the assessment criteria evaluated (p>0,05), just as happened with the 4 times of evaluation for all groups (p>0,05). With regards to the logistic regression, although it has not presented any isolated variable as statistically significant, the model as a whole showed statistically significant (p=0,034). Conclusion: The four different adhesive strategies in non-carious cervical restorations showed similar clinical performance after 24 months of follow-up.
FAPESP: 2014/07086-0

Este estudo in situ, desenvolvido em uma fase de 14 dias, teve como objetivo avaliar o efeito de dois cimentos de ionômero de vidro (CIV) comparados a um selante resinoso, utilizados para selamento de fossas e fissuras aplicados em esmalte bovino hígido, com acúmulo de biofilme dentário, por meio da análise do conteúdo de flúor do biofilme dentário e da microdureza em secção longitudinal. Foram utilizados 88 blocos de esmalte (4mm x 4mm) de incisivos bovinos, selecionados por seu valor de microdureza inicial. Os blocos formaram uma fissura artificial em forma de \"V\" a qual foi selada, para compor os seguintes grupos: GI-CIVav (Ketac? Molar Easymix); GII-CIV modificado por resina (Vitremer?); GIII-selante resinoso sem flúor (Helioseal® Clear) ou GIV-controle, sem selamento. As fissuras artificiais foram fixadas em um dispositivo intrabucal palatino (DIP), em duas fileiras distintas que foram cobertas por uma tela plástica para favorecer o acúmulo de biofilme dentário. Onze voluntários utilizaram o DIP 24 h/dia; gotejaram 8x/dia, uma solução de sacarose a 20% e, uma solução de dentifrício fluoretado (3ml de água deionizada : 1g de dentifrício fluoretado) sobre todas as fissuras 3x/dia. Após o período experimental, coletou-se o biofilme acumulado para a avaliação do conteúdo de flúor. As fissuras foram seccionadas ao meio para a avaliação da microdureza em secção longitudinal a partir da superfície do esmalte, em 4 profundidades (10, 30, 50, 70 µm). O limite esmalte/material da região oclusal era a posição zero (borda do material) e, a partir deste, realizadas seqüências de impressões a 50, 150 e 500 µm interna e externamente à borda do material. Os dados obtidos foram analisados estatisticamente (a= 5%). O teste de Friedman revelou que a concentração de flúor no biofilme não foi estatisticamente significante entre os grupos, (p<0,07), com uma tendência de melhores resultados para o CIVav. Quanto ao conteúdo mineral, a ANOVA e o teste de Tukey detectaram significância (p<0,05) para todos os grupos individualmente, na camada mais superficial do esmalte (10 µm). Nesta profundidade, não houve diferença entre os grupos. Essas comparações foram válidas para a maioria das distâncias analisadas.
This in situ study, developed in a 14-day period, aimed to evaluate the effect of two glass ionomer cements (GIC) compared to a resin sealant, employed for pit and fissure sealing on intact bovine enamel, with accumulation of dental biofilm, by analysis of the fluoride content on the dental biofilm and longitudinal microhardness. Eighty-eight enamel blocks (4mm x 4mm) of bovine incisors were employed, selected according to their initial microhardness value. The blocks formed a V-shaped artificial fissure that was sealed, constituting the following groups: GI - high-viscosity conventional GIC (Ketac? Molar Easymix); GII - resin-modified GIC (Vitremer?); GIII - resin sealant without fluoride (Helioseal? Clear); and GIV - control, without sealing. The artificial fissures were fixated on a palatal plate (PP), in two distinct rows, which were covered with a plastic screen to favor the accumulation of dental biofilm. Eleven volunteers employed the PP for 24h/day, dripped a 20% sucrose solution 8 times a day, and used a fluoridated dentifrice solution (3ml of deionized water : 1g of fluoridated dentifrice) on all fissures 3 times a day. After the study period, the accumulated biofilm was collected for evaluation of the fluoride content. The fissures were sectioned through the middle for evaluation of longitudinal microhardness from the enamel surface, at 4 depths (10, 30, 50, 70 µm). The enamel/material limit at the occlusal region was the zero position (material margin); from this point, indents were sequentially performed at 50, 150 and 500 µm internally and externally to the material margin. Data were statistically analyzed (a = 5%). The Friedman test revealed that the fluoride concentration in the biofilm was not statistically significantly different among groups (p<0.07), yet there was a tendency of better outcomes for the high-viscosity conventional GIC. With regard to the mineral content, the ANOVA and Tukey test revealed significance (p<0.05) for all groups individually, at the most superficial enamel layer (10 µm). At this depth, there was no difference among groups. These comparisons were valid for most distances analyzed..

Дисертація на здобуття наукового ступеня доктора технічних наук за спеціальністю 05.17.11 – технологія тугоплавких неметалічних матеріалів, Державний вищий навчальний заклад "Український державний хіміко-технологічний університет", Національний технічний університет "Харківський політехнічний інститут". Дисертацію присвячено науковим основам технології екологічно безпечних склоемалевих покриттів широкої колірної гами для сталі і кольорових металів, розробці принципів регулювання та прогнозування їх кольору. Розроблена спеціальна комп’ютерна програма COLOUR GLASS, яка за визначеними координатами кольору XYZ автоматично розташовує точки кольору на графіку МКО. Отримані емалі ювелірного та художнього призначення на основі стекол системи Na₂O–BaO–B₂O₃–SiO₂. Розроблені малофлуористі білі і світлозабарвлені титанові емалі, безфлуориста основа для пігментного способу забарвлення. Створено метод колірного моделювання, за допомогою якого можна розрахувати співвідношення пігментів для відтворення кольору зразка за заданими колірними характеристиками.
Thesis for a Doctor of Science Degree in Specialty 05.17.11 Refractory Non-Metallic Materials Technology, State Higher Educational Institution "Ukrainian State University of Chemical Technology", National Technical University "Kharkiv Polytechnic Institute". The dissertation is devoted to development of scientific bases of technology of ecologically safe protective and decorative glass-enamel coatings of wide color scale on steel and non-ferrous metals, making of principles of regulation and prediction of their color. The introduction substantiates the relevance of the dissertation topic, formulates the main purpose and objectives of the work. The first section provides an analysis of the patent and scientific and technical literature. The second section provides the basic concepts and definitions used in the work, methods for investigating the physicochemical properties and structure of glasses and coatings and their color characteristics. The third section presents studies on the development of environmentally safe enamels for copper and the prediction of their color characteristics. The fourth section presents the results of studies on the development of small fluoride titanium enamel with a firing temperature of 830 °C. The fifth section had devoted to scientific bases of technology of fluorless enamel frits for pigment method of coloring. The sixth section has devoted to the development of the color modeling method for reproducing the color of a sample with specified color characteristics. In the seventh section the results of industrial testing, implementation and implementation of the received materials has presented. As a result of the research on the topic of dissertation the following scientific results has obtained: - scientifically substantiated and experimentally proved that the production of lead-free enamel coatings on non-ferrous metals is possible on the basis of the Na₂O–BaO–B₂O₃–SiO₂ glasses, the regions of glass formation has been determined, and the regularities of changes in the properties of glasses depending on their chemical composition has been established; - the main tendencies of change of glasses color tone has established in the Na₂O–BaO–B₂O₃–SiO₂ system, which has colored by ionic dyes given the structural features of the glasses and their acid-base properties; - it has been proved that the degree of color intensity of glasses in the system R₂O –BaO – ZnO – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ and coatings based on them has been arranged in the following sequence: CoO> NiO> CuO> K₂Cr₂O₇> Fe₂O₃; - for the first time the mechanism of opacifying of transparent matrix enamel glass in the R₂O – BaO – ZnO – TiO₂ – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ system was introduced when MoO₃ has been established, namely: due to diffraction, which results in the phenomenon of opalescence; - for the first time the dependence of the diffuse reflection coefficient of enamel coatings on the chemical composition of enamel frits has been established, which is presented in the form of a mathematical model; the correlation coefficient between experimental and calculated values is 0.98; - for the first time the mechanism of opacifying of transparent matrix enamel glass in the R₂O – BaO – ZnO – TiO₂ – Al₂O₃ – B₂O₃ – TiO₂ – SiO₂ system was introduced when MoO3 has been established, namely: due to diffraction, which results in the phenomenon of opalescence; - for the first time it has been discovered that Fe₂O₃ "small additive" in the amount of 0.25 wt.% in the composition of lead-free enamel glasses on the basis of the Na₂O – BaO – B₂O₃ – SiO₂ base system and 1 wt. Fe₂O₃ in the composition of fluor-free enamel glasses on the basis of the Na₂O – B₂O₃ – SiO₂ base system activates the processes of glass removal stratification, which allows to increase 1.5-2.5 times the intensity of coating damping; - with the help of a special computer program COLOR GLASS, which automatically calculates the coordinates of the color x, y, the color tone λ, the purity of the color P and applies the color characteristics of the materials to the CIE graph, it has been proved for the first time that the chart of the location of color points can make forecasts about the equilibrium, which formed between ionic coloring complexes during glass melting; - for the first time in the field of technologies requiring high temperatures, the dependences of the color coordinates of enamel coatings on the composition of the pigment mixture in the form of polynomial mathematical models has been established, which allowed to solve the complex material-coloristic problem of finding the ratio of pigments to reproduce the color of the sample with the specified color characteristics. The practical significance of the obtained results: - the compositions of enamel art and jewelry glasses for non-ferrous metals, which do not contain Plumbum, has been developed. They are characterized by the same firing interval of 780-820 °C. A catalog of color samples has created. The palette includes fondon and 53 colors: yellow-red, blue-green, olive-mustard, pastel and brown-black; - a series of compositions of white and light-colored titanium enamels containing reduced amount of Fluorine (up to 2.5 wt.%), has been developed, also the composition of fluorless frites to obtain brightly colored enamel coatings pigmented way of color. Temperature operations of the enamel melting is 100 °C and firing of coatings is 30-50oC below the known ones.

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O objetivo deste trabalho, dividido em três estudos, foi investigar (1) a reparabilidade de um cimento de ionômero de vidro modificado por resina, (2) o efeito cariostático e (3) a retenção de selantes ionoméricos aderidos ao esmalte não desgastado com sistemas adesivos autocondicionantes simplificados. Materiais e Métodos: Para o estudo 1 foram confeccionados 60 espécimes de cada material, Vitremer (VT) e resina Z250 (RC). Após envelhecimento químico e térmico, eles foram divididos em 3 grupos de acordo com o tratamento mecânico da superfície: ponta diamantada em alta rotação, ponta em ultra-som e sem desgaste. Cada espécime foi reparado com o mesmo material utilizado inicialmente. Aplicou-se na superfície do VT o Vitremer Primer (VP), e para a resina, utilizou-se ácido fosfórico seguido de adesivo Single Bond. Os espécimes foram isolados deixando exposta a interface de união. Após novo envelhecimento, os mesmos foram impregnados por nitrato de prata, seccionados e avaliados quanto à infiltração e formação de fendas. Os dados foram analisados pelos testes de Kruskal-Wallis e Mann-Whitney (α=0,05). No segundo estudo 64 incisivos bovinos foram distribuídos em 4 grupos segundo o tratamento da superfície de esmalte: VP, Prompt L-Pop (Pr), Xeno III (Xe) ou sem tratamento. Um cilindro de VT foi construído em metade dos dentes, enquanto que a RC foi utilizada na outra metade. Os corpos de prova foram 19 submetidos a desafio cariogênico e seccionados, para realização de testes de dureza em três regiões: externa, união e interna, até a profundidade de 300 μm. Os dados transformados em porcentagem de perda mineral foram analisados pelo teste de ANOVA complementado pelo teste de Tukey ao nível de significância de 5%. No terceiro estudo, 20 pares de molares permanentes hígidos foram selecionados de crianças entre 6 e 10 anos. Em um dos dentes foi aplicado...
The purpose of this work, divided into three studies, was to investigate (1) the reparability of a resin-modified glass-ionomer cement, as well as (2) the cariostatic effect and (3) retention of glass-ionomer sealants bonded to enamel with one-step self-etching adhesive systems. Materials and Methods: For the first study, 60 specimens were prepared with Vitremer (VT) and Z250 resin. After chemical and thermal aging, the specimens were divided into 3 groups according to the mechanical treatment of the surface: diamond bur, ultrasound coupled bur or no treatment. Each specimen was repaired with the original restorative material. For VT repairs, Vitremer Primer (VP) was first applied while for composite resin the surface was phosphoric acid etched followed by the application of Single Bond. The specimens were coated with acid resistant varnish except for 1 mm around de interface. After additional aging, the specimens were impregnated by silver nitrate and sectioned medialy for the evaluation of silver infiltration and gap formation in SEM. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). In the second study, 64 bovine teeth were randomly assigned to 4 groups according to the enamel surface treatment: VP, Prompt L-Pop (Pr), Xeno III (Xe) or no treatment. A cylinder of VT was built up in half of the teeth while a composite resin was used in the other half. The teeth were then submitted to a cariogenic challenge after which they 23 were medialy cut. Transversal hardeness evaluation was performed in three regions, external, interface and internal, up to the depth of 300μm. Hardness numbers were converted to percentage of mineral loss and the data were submitted to ANOVA and Tukey tests at the level of significance of 5%. For the third study, 20 pairs of sound permanent molars were selected from children between 6 and 10 years of age. One tooth of the pair received... (Complete abstract click electronic access below)

Materials and methods used in the production of modernist (late 19th and early 20th century) stained glass from the city of Barcelona with special regards to the degradation mechanisms of enamels, grisailles and silver stains have been studied. Coloured enamels from the raw materials used in the Rigalt, Granell & cia modernist workshops from Barcelona were produced and compared to those found in the buildings and belonging to the private collection of J.M. Bonet workshop to explore the reason for the reduced stability of the blue and green enamels. The chemical composition has been determined (and pigments identified) by means of Laser Ablation Inductively-Coupled Plasma Mass Spectrometry (LA-ICP-MS), X-Ray Diffraction (XRD) and UV-Vis-NIR spectroscopy, and the thermal properties of the enamels measured by Differential Scanning Calorimetry (DSC) and Hot Stage Microscopy (HSM). The enamels are made of a lead-zinc borosilicate glass characterised by its low sintering temperatures and high stability against chemical corrosion, in particular to water corrosion. However, the relatively narrow range of firing temperatures necessary for correct adherence of the enamels to the contemporary glass base may have required the addition of a high lead borosilicate flux, which would have increased the lead content of the enamel, decreasing the firing temperature but also its stability. The historical enamels show a lead, boron and zinc depleted silica rich amorphous glass, with precipitated lead and calcium sulphates or carbonates, characteristic of extensive atmospheric corrosion. The blue and green enamels show a heterogeneous layered microstructure more prone to degradation which is augmented by a greater heating and thermal stress affectation produced by the enhanced Infrared absorbance of blue tetrahedral cobalt colour centres and copper ions dissolved in the glass and, in particular, of the cobalt spinel particles
S'han estudiat els materials i mètodes utilitzats en la producció dels vitralls modernistes (finals del segle XIX i començaments del segle XX) de la ciutat de Barcelona, especialment en relació als mecanismes de degradació d’esmalts, grisalles i grocs de plata. S'han produït i estudiat els esmalts de color a partir de les matèries primeres utilitzades pel taller Rigalt, Granell & cia de Barcelona, per comparar amb mostres originals pertanyents a la col·lecció privada del taller J.M. Bonet vitralls per així estudiar la raó de la reduïda estabilitat dels esmalts blaus i verds. La composició química i els pigments han estat identificats per LA-ICP-MS, espectroscòpia d'UV-Vis-NIR i XRD, i les propietats tèrmiques dels esmalts han estat mesurades amb DSC i HSM. Els esmalts són vidres borosilicats de plom i zinc caracteritzats per baixes temperatures de sinterització i una gran estabilitat contra la corrosió química, especialment respecte a la corrosió de l'aigua. No obstant, el relativament estret marge de temperatures necessari per una correcta adherència dels esmalts al vidre base de l’època podria haver requerit l’addició d’un fundent amb un alt tant per cent de plom i bor, que podria haver augmentat la proporció de plom a l’esmalt disminuint la temperatura de treball juntament amb la seva estabilitat. Els esmalts històrics presenten una composició alterada a on plom, bor i zinc han disminuït en front a un augment de la proporció de silici a la fase vítria, amb l’aparició de precipitats de sulfats o carbonats de plom i calci, característics de l’efecte de la corrosió atmosfèrica. Els esmalts blaus i verds presenten una microestructura en capes heterogènies que són més susceptibles a la degradació, la qual augmenta degut a la calor i l’estrès tèrmic respecte al vidre base que provoca una major absorbància a la regió de l’infraroig proper deguda a la presència d’estructures tetraèdriques dels ions de cobalt i coure dissoltes a la fase vítria, i en particular de les partícules d'espinel·les de cobalt
Se han estudiado los materiales y métodos utilizados en la producción de los vitrales modernistas (finales del siglo XIX y principios del siglo XX) de la ciudad de Barcelona, especialmente en relación a los mecanismos de degradación de esmaltes, grisallas y amarillos de plata. Se han producido y estudiado los esmaltes de color a partir de las materias primas utilizadas por el taller Rigalt, Granell & cia de Barcelona, para luego comparar con muestras originales de la colección privada del taller J.M. Bonet vitralls y así estudiar la razón de la reducida estabilidad de los esmaltes azules y verdes. La composición química y los pigmentos han sido identificados por LA-ICP-MS, espectroscopía UV-Vis-NIR, y las propiedades térmicas de los esmaltes han sido medidas con DSC y HSM. Los esmaltes son vidrios borosilicatos de plomo y zinc caracterizados por bajas temperaturas de sinterizado y una gran estabilidad contra la corrosión química, especialmente contra la corrosión del agua. No obstante, el relativamente estrecho margen de temperaturas necesario para una correcta adherencia de los esmaltes al vidrio base de la época podría haber requerido la adición de un fundente con un alto tanto por ciento de plomo y boro, que podría haber aumentado la proporción de plomo en el esmalte disminuyendo la temperatura de trabajo junto con su estabilidad. Los esmaltes históricos presentan una composición alterada donde plomo, boro y zinc han disminuido a favor de un aumento de la proporción de silicio en la fase vítrea, con la aparición de precipitados de sulfatos o carbonatos de plomo y calcio, característicos del efecto de la corrosión atmosférica. Los esmaltes azules y verdes presentan una microestructura en capas heterogéneas que es mas susceptible a la degradación, que aumenta debido a la temperatura y al estrés térmico respecto al vidrio base que provoca una mayor absorbancia en la región del infrarrojo cercano debido a la presencia de estructuras tetraédricas de los iones de cobalto y cobre disueltos en la fase vítrea, así como a la presencia de partículas de espinelas de cobalto

O objetivo deste estudo in vitro foi avaliar a perda mineral no esmalte adjacente a cavidades preparadas com laser de Er,Cr:YSGG e restauradas com diferentes materiais, liberadores ou não de flúor, após desafio ácido. Cento e vinte blocos de esmalte dental de terceiros molares humanos (4 x4 mm) foram aleatoriamente divididas em 12 grupos (n=10) de acordo com a técnica de preparo: G1- alta-rotação (AR); G2- Laser de Er,Cr:YSGG (3W, 20Hz, 53,05 J/cm2)(65% ar, 55% água); G3- Laser de Er,Cr:YSGG (4 W, 20 Hz, 70,74 J/cm2); G4- Laser de Er,Cr:YSGG (5 W, 20 Hz, 88,43 J/cm2). Cada grupo experimental foi dividido em subgrupos, conforme o material restaurador utilizado: 1- cimento de ionômero de vidro (CIV), 2- cimento de ionômero de vidro resino modificado (CIVRM), 3- sistema adesivo e resina composta (RC). As amostras foram submetidas a desafio ácido (pH 4,8) por 7 dias. As concentrações do íon cálcio nas soluções desmineralizadoras (ppm/mm2), nos diferentes tempos (1, 3 e 7 dias), foram analisadas por espectrofotometria de emissão atômica. Os dados obtidos foram analisados usando os testes estatísticos ANOVA e LSD (?=5%) mostrando haver diferenças significativas entre Técnica e Material Restaurador no tempo total. Os menores valores médios da perda de cálcio foram obtidos nos grupos G2 + CIV, G2 + CIVRM e G1 + CIVRM; os maiores valores foram observados nos grupos de G1 + RC, G4 + CIV e G4 + RC. As restaurações de RC apresentaram maior perda mineral que as de CIV e CIVRM; os preparos com laser utilizando menor radiância (53,05J/cm2) apresentaram significante menor desmineralização que as maiores radiâncias (70,74 e 88,43J/cm2). Nenhuma técnica ou material impediu a desmineralização do esmalte. Os resultados deste estudo in vitro sugerem que a realização de preparos cavitários com laser de Er,Cr:YSGG (53,05J/cm2) restaurados com CIV e CIVRM ou alta-rotação e CIVRM foram efetivos na redução da perda mineral e aumento da resistência ácida do esmalte adjacente as restaurações após desafio ácido, com importante potencial em prevenir lesões de cárie secundária.
The aim of this study was to evaluate the enamel calcium loss around cavities prepared by Er,Cr:YSGG laser and restored with different materials after an acid challenge. One hundred and twenty enamel samples obtained from third molars (4 x 4 mm) were randomly divided in 12 groups (n=10) using different techniques: G1- high-speed drill (HD); G2- Er,Cr:YSGG laser (3W, 20Hz, 53.05 J/cm2)(air 65% - water 55%); G3- Er,Cr:YSGG laser (4 W, 20 Hz, 70.74 J/cm2); G4- Er,Cr:YSGG laser (5 W, 20 Hz, 88.43 J/cm2). Each experimental group was divided in subgroups, according to the restorative material: 1 - glass ionomer cement (GIC), 2 - resin modified GIC (RMGIC), 3 - adhesive system and composite resin (C). Samples were submitted to an acid challenge (4.8 pH) for 7 days. The Demineralizing solutions were analyzed in relation to the calcium ion contend (ppm/mm2), in different times (1, 3 and 7 days), under atomic emission spectrometry. ANOVA and LSD tests were performed (?=5%). There were significant difference between Technique and Restorative Material on Total Time. The lower average values of calcium loss were observed on G2 + GIC, G2 + RMGIC, G1 + RMGIC groups; the higher values were observed on G1 + C, G4 +GIC, G4 + C. The composite resin showed higher calcium loss than RMGIC and GIC. The lased cavities using lower fluence (53.05J/cm2) showed significant reduced demineralization than higher fluences (70.74 and 88.43J/cm2). Neither the techniques nor the restorative materials used were able to prevent the enamel demineralization. The findings of this in vitro study suggest that the Er,Cr:YSGG lased cavities (53.05J/cm2) restored with GIC or RMGIC or conventional drill cavities with RMGIC were effective on reducing the mineral loss and enhancing the enamel acid resistant around restorations after the acid challenge, showing an important potential in preventing secondary caries.

Orientador: Josimeri Hebling
Banca: Elisa Aparecida Maria Giro
Banca: Angela Cristina Cilense Zuanon
Banca: Célia Regina Moreira Lanza
Banca: Darlon Martins Lima
Resumo: O objetivo deste trabalho, dividido em três estudos, foi investigar (1) a reparabilidade de um cimento de ionômero de vidro modificado por resina, (2) o efeito cariostático e (3) a retenção de selantes ionoméricos aderidos ao esmalte não desgastado com sistemas adesivos autocondicionantes simplificados. Materiais e Métodos: Para o estudo 1 foram confeccionados 60 espécimes de cada material, Vitremer (VT) e resina Z250 (RC). Após envelhecimento químico e térmico, eles foram divididos em 3 grupos de acordo com o tratamento mecânico da superfície: ponta diamantada em alta rotação, ponta em ultra-som e sem desgaste. Cada espécime foi reparado com o mesmo material utilizado inicialmente. Aplicou-se na superfície do VT o Vitremer Primer (VP), e para a resina, utilizou-se ácido fosfórico seguido de adesivo Single Bond. Os espécimes foram isolados deixando exposta a interface de união. Após novo envelhecimento, os mesmos foram impregnados por nitrato de prata, seccionados e avaliados quanto à infiltração e formação de fendas. Os dados foram analisados pelos testes de Kruskal-Wallis e Mann-Whitney (α=0,05). No segundo estudo 64 incisivos bovinos foram distribuídos em 4 grupos segundo o tratamento da superfície de esmalte: VP, Prompt L-Pop (Pr), Xeno III (Xe) ou sem tratamento. Um cilindro de VT foi construído em metade dos dentes, enquanto que a RC foi utilizada na outra metade. Os corpos de prova foram 19 submetidos a desafio cariogênico e seccionados, para realização de testes de dureza em três regiões: externa, união e interna, até a profundidade de 300 μm. Os dados transformados em porcentagem de perda mineral foram analisados pelo teste de ANOVA complementado pelo teste de Tukey ao nível de significância de 5%. No terceiro estudo, 20 pares de molares permanentes hígidos foram selecionados de crianças entre 6 e 10 anos. Em um dos dentes foi aplicado... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The purpose of this work, divided into three studies, was to investigate (1) the reparability of a resin-modified glass-ionomer cement, as well as (2) the cariostatic effect and (3) retention of glass-ionomer sealants bonded to enamel with one-step self-etching adhesive systems. Materials and Methods: For the first study, 60 specimens were prepared with Vitremer (VT) and Z250 resin. After chemical and thermal aging, the specimens were divided into 3 groups according to the mechanical treatment of the surface: diamond bur, ultrasound coupled bur or no treatment. Each specimen was repaired with the original restorative material. For VT repairs, Vitremer Primer (VP) was first applied while for composite resin the surface was phosphoric acid etched followed by the application of Single Bond. The specimens were coated with acid resistant varnish except for 1 mm around de interface. After additional aging, the specimens were impregnated by silver nitrate and sectioned medialy for the evaluation of silver infiltration and gap formation in SEM. Data were submitted to Kruskal-Wallis and Mann-Whitney tests (α=0.05). In the second study, 64 bovine teeth were randomly assigned to 4 groups according to the enamel surface treatment: VP, Prompt L-Pop (Pr), Xeno III (Xe) or no treatment. A cylinder of VT was built up in half of the teeth while a composite resin was used in the other half. The teeth were then submitted to a cariogenic challenge after which they 23 were medialy cut. Transversal hardeness evaluation was performed in three regions, external, interface and internal, up to the depth of 300μm. Hardness numbers were converted to percentage of mineral loss and the data were submitted to ANOVA and Tukey tests at the level of significance of 5%. For the third study, 20 pairs of sound permanent molars were selected from children between 6 and 10 years of age. One tooth of the pair received... (Complete abstract click electronic access below)
Doutor

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.17.11 "Технологія тугоплавких неметалічних матеріалів". – Національний технічний університет "Харківський політехнічний інститут", Харків, 2017. Дисертацію присвячено розробці безпігментних одношарових хімічно та термічно стійких темнозабарвлених склоемалевих покриттів для захисту побутової техніки, зокрема кухонних газових та електричних плит, що отримуються за технологією POESTA. Синтезовано основи отримання покриттів вказаного типу, згідно із якими розробляється скломатриця із заданими фізико-хімічними властивостями, на основі якої отримується склоемалева фрита шляхом введення в оптимізований склад скла комплексного активатору зчеплення, одночасно виконуючий роль активного забарвлюючого комплексу, який поєднує задані міцнісні характеристики безпігментних одношарових темнозабарвлених склоемалевих покриттів. Встановлено межі значень структурних факторів, які забезпечують міцну структуру кремнекисневого каркасу скла в системі R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ і заданий рівень її структурнозалежних експлуатаційних властивостей за рахунок встановлених співвідношень склоутворювачів і модифікаторів. Розроблено склад і співвідношення комплексного активатора зчеплення із урахуванням його впливу на характеристики міцності системи "склоемаль – сталь", корозійну здатність склорозплаву та експлуатаційні властивості покриттів, який одночасно виконує роль активного забарвлюючого комплексу. Обрано іонний механізм забарвлення та встановлено колірні координати в ККС XYZ, RGB, L*a*b. Проведено промислові та лабораторно-промислові випробування на підприємствах та розроблено практичні рекомендації щодо використання результатів.
The dissertation on competion of a scientific degree of the candidate of engineering science on a speciality 05.17.11 "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2017. The dissertation is devoted to the development of pigments free direct chemically and thermally resistant dark-colored glass-enamel coatings for the protection of household appliances, in particular kitchen gas and electric plates, obtained by the technology POESTA. The bases of obtaining the coatings of this type are synthesized, according to which the glass matrix is developed with the given physicochemical properties, on the basis of which glassmelee frit is obtained by introducing into the optimized composition of the MS complex agglomer activator, simultaneously performing the role of the active coloring complex which combines the specified strength characteristics of pigments free direct glass-enamel coatings with their dark coloring. The boundaries of the values of structural factors, which provide a solid structure of the silica-oxygen glass frame in the system R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ and the specified level of its structurally dependent performance properties due to the established ratios of glass modifiers and modifiers. The composition and ratio of the complex coupler activator have been developed taking into account its influence on the strength characteristics of the glass-enamel-steel system, the corrosion capacity of the glass-fiber alloy and the operational properties of the coatings at the firing temperatures of 800 to 830 °C. Selected the ionic mechanism of color, which was realized by the components of the filling station, and the color coordinates are established in the XYZ, RGB, L*a*b, according to RAL. Industrial and laboratory-industrial tests were carried and practical recommendations for the use of development results are developed.

Дисертація на здобуття наукового ступеня кандидата технічних наук (доктора філософії) за спеціальністю 05.17.11 "Технологія тугоплавких неметалічних матеріалів". – Національний технічний університет "Харківський політехнічний інститут", Харків, 2017. Дисертацію присвячено розробці безпігментних одношарових хімічно та термічно стійких темнозабарвлених склоемалевих покриттів для захисту побутової техніки, зокрема кухонних газових та електричних плит, що отримуються за технологією POESTA. Синтезовано основи отримання покриттів вказаного типу, згідно із якими розробляється скломатриця із заданими фізико-хімічними властивостями, на основі якої отримується склоемалева фрита шляхом введення в оптимізований склад скла комплексного активатору зчеплення, одночасно виконуючий роль активного забарвлюючого комплексу, який поєднує задані міцнісні характеристики безпігментних одношарових темнозабарвлених склоемалевих покриттів. Встановлено межі значень структурних факторів, які забезпечують міцну структуру кремнекисневого каркасу скла в системі R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ і заданий рівень її структурнозалежних експлуатаційних властивостей за рахунок встановлених співвідношень склоутворювачів і модифікаторів. Розроблено склад і співвідношення комплексного активатора зчеплення із урахуванням його впливу на характеристики міцності системи "склоемаль – сталь", корозійну здатність склорозплаву та експлуатаційні властивості покриттів, який одночасно виконує роль активного забарвлюючого комплексу. Обрано іонний механізм забарвлення та встановлено колірні координати в ККС XYZ, RGB, L*a*b. Проведено промислові та лабораторно-промислові випробування на підприємствах та розроблено практичні рекомендації щодо використання результатів.
The dissertation on competion of a scientific degree of the candidate of engineering science on a speciality 05.17.11 "Technology of refractory nonmetallic materials". – National Technical University "Kharkiv Polytechnical Institute", Kharkiv, 2017. The dissertation is devoted to the development of pigments free direct chemically and thermally resistant dark-colored glass-enamel coatings for the protection of household appliances, in particular kitchen gas and electric plates, obtained by the technology POESTA. The bases of obtaining the coatings of this type are synthesized, according to which the glass matrix is developed with the given physicochemical properties, on the basis of which glassmelee frit is obtained by introducing into the optimized composition of the MS complex agglomer activator, simultaneously performing the role of the active coloring complex which combines the specified strength characteristics of pigments free direct glass-enamel coatings with their dark coloring. The boundaries of the values of structural factors, which provide a solid structure of the silica-oxygen glass frame in the system R₂O (Na₂O+K₂O+Li₂O) – RO (CaO+BaO+SrO+MgO) – TiO₂ – ZrO₂ – B₂O₃ – SiO₂ and the specified level of its structurally dependent performance properties due to the established ratios of glass modifiers and modifiers. The composition and ratio of the complex coupler activator have been developed taking into account its influence on the strength characteristics of the glass-enamel-steel system, the corrosion capacity of the glass-fiber alloy and the operational properties of the coatings at the firing temperatures of 800 to 830 °C. Selected the ionic mechanism of color, which was realized by the components of the filling station, and the color coordinates are established in the XYZ, RGB, L*a*b, according to RAL. Industrial and laboratory-industrial tests were carried and practical recommendations for the use of development results are developed.

The objective of this study was to identify the strategies (personal and organisational) that would enable South African women to break through the glass ceiling. A questionaire was designed based on the strategies found in a literature study on the topic and used to gather inputs from executive women in South Africa. A combination of snowball and self-selection sampling was used. The questionaire was sent to 138 potential respondents, mostly by means of electronic mail. Of the 47 completed questionairs returned, 44 could be used. These were processed and anaylsed using Microsoft Excel spreadsheets and the STATISTICA Version 6 software. In generaL, support was found for personal strategies pertaining to career management, networking (especially the relationship building activities), the reconciliation of home and work responsibilities with the emphasis on building a support system, education, business and organisational insught, skills development and increased input, but not for the assimilation of masculine attributes. Networking opportunities and education, training and development activities were regarded as the organisational strategies with the strongest impact on career progress. The literature was confirmed regarding top management support, an organisational culture conducive to women's advancement, mentorship programmes and a few career development initiatives. Although more than half of the respondents had been exposed to employment equity and affirmative action programmes, they were perceived to have only little to moderate impact on career progress. This was also the case with diversity management programmes. Flexible work arrangements, career adaptation schemes and childcare facilities and programmes were seen as having had little impact on the respondents' career advancement. Only a few of the organisational practices to support women balancing family and work responsibilities were utilised by the respondents' employers. Respondents perceived personal strategies as having greater value than organisational strategies in their progress to executive levels.

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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

This research investigates the synthesis and manufacture of shape-memory polymer (SMP) systems for use in biomedical and commodity applications. The research centers on improving the mechanical properties of thermoset acrylate copolymers with memory properties at reasonable cost through various design and manufacturing techniques: high-strain polymer synthesis and radiation crosslinking. The research assesses combinations of linear monomers and a low density of crosslinker to characterize new functional materials and optimize emerging mechanical properties such as the glass transition temperature (Tg) and rubbery modulus (ER). Exploring materials with large recoverable strains, a model copolymer of photo-polymerized methyl acrylate (MA), isobornyl acrylate and crosslinker bisphenol A ethoxylate dimethacrylate was shown to strain above 800%, twice the previously published value for SMPs, and recover fully. In the quest to maximize fully recoverable strains, a new hybrid molecule nicknamed Xini, which serves as both an initiator and a crosslinker, was also theorized, synthesized, polymerized into SMP networks and characterized. In the past, thermoset SMPs were made into complex shapes using expensive top-down techniques. A block of polymer was made and custom machining was required to craft complex parts. This prohibited devices in cost-competitive commodity application spaces. This research has proposed and validated a new method for accurately tuning the thermomechanical properties of network acrylates with shape-memory properties: Mnemosynation, eponymously named for the Greek goddess of memory. This novel manufacturing process imparts long term 'memory' on an otherwise amorphous thermoplastic material utilizing radiation-induced covalent crosslinking, and can be likened to Vulcanization, which imparts strength on natural rubber utilizing sulfur crosslinks. Adjustment of ER in the range from below 1 MPa to above 13 MPa has been demonstrated. ER was tailored by varying both radiation dose between 5 and 300 kGy and crosslinker concentration between 1.00 and 25.0 wt%. Tg manipulation was demonstrated between 23 ˚C and 70 ˚C. Mnemosynation combines advances in radiation grafting and acrylic SMP synthesis to enable both traditional plastics processing (blow molding, injection molding, etc.) and control of thermoset shape-memory properties. Combining advances in both high strain polymer synthesis and radiation crosslinking, a new paradigm in SMP composites manufacture-namely, that materials can be designed to enhance strain capacity at moderate stress, rather than maximum strength-was established. Various fibers with very different mechanical properties were impregnated with SMPs and thermo-mechanically assessed to develop an understanding of the technical parameters necessary to craft self-adjusting, multi-actuated, SMP-fiber composite orthopedic casts. This exploration syncs with the overarching aim of the research, which is to understand the fundamental scientific drivers necessary to enable new devices mass-manufactured from acrylate copolymers and optimize their emerging mechanical properties.

Indiana University-Purdue University Indianapolis (IUPUI)
While most sealants available are resin-based, glass ionomer-based cements can be used as sealants, with the advantage of being more tolerant to moisture during placement and of releasing fluoride. The objective of this study was to evaluate the influence of different fissure conditioning techniques on penetration and microleakage of glass ionomer (GI) and resin-modified glass ionomer cements (RMGI) used as sealants. Clinically sound extracted human molars were distributed into nine experimental groups (n = 15 each). Group 1 (control) was sealed with resin-based sealant (Delton) following clinically accepted techniques. Groups 2 through 6 were sealed with RMGI (Vitremer) after having the fissure conditioned with either polyacrylic acid (RMGI-control), 35-percent H3PO4, low viscosity 35-percent H3PO4 with a surfactant, self-etch conditioner, or 35-percent H3PO4 followed by self-etch conditioner. Groups 7 through 9 were sealed with GI sealant (Fuji Triage) after having the fissures conditioned with either polyacrylic acid (GI-control), 35- percent H3PO4 or low viscosity 35-percent H3PO4 with a surfactant. After aging through thermocycling (2500 cycles), specimens were incubated in methylene blue for four hours and sectioned at multiple locations. Digital images were obtained using a digital stereomicroscope, and microleakage was determined by scoring the dye penetration along the enamel-sealant interface. The penetration of the material was determined by calculating the percentage of the total length of the fissure penetrated by the material. Results: The use of self etch-conditioner significantly increased RMGI penetration, while surface conditioning with 35-percent phosphoric acid with surfactant significantly decreased microleakage of GI. The resin-based sealant placed after 35-percent phosphoric acid surface conditioning showed the best penetration and the least level of microleakage. In conclusion, results from this study suggest that the placement of glass ionomer-based sealants can be enhanced by modifying current conditioning methods.

碩士
國立臺灣大學
臨床牙醫學研究所
93
英文摘要 Objective: To evaluate the retention and efficacy of the GIC sealants on the saliva contaminated enamel surface after air-dry procedure in clinical situation. Method: The initial population consisted of 220 schoolchildren, ages 6-8 years, whose permanent molars were sound sealed. A GIC (Fuji IX) was used as sealant material. All sealants were placed in a school setting by the same dentist. The teeth were randomly assigned to control side on which the treatment procedures were followed with manufacture’s instruction. The contralateral tooth surface was intentionally contaminated with saliva then air-dried without rinse before sealant placement. Evaluations were done with a dental probe with light pressure. Double-blind recall examinations for sealant retention were done at 3 months intervals until 18 months. 178 subjects returned for evaluation after 18 months. Results: After 18 months, 17.9% of the sealed teeth showed complete present, 35.3% partial present without caries, 45.3% complete loss without caries, and 1.5% caries or filled on occlusal surface of the contaminated side. In control side, the corresponding figures were 22.6%, 42.1%, 33.7% and 1.6%, respectively. Statistical analysis (Chi square test) revealed that there were no significant difference between the retention rate of the experimental side and the control side in the study periods. As to caries incidence, there was no significant difference (McNemar’s test) between experimental side and control side. Conclusion: Air drying to the saliva contaminated enamel without rinse prior to GIC placement seems to have comparable retention rate to teeth with regular procedure.

碩士
國立臺灣大學
牙醫學系
85
Pit and fissure sealant is the primary method used to prevent occlusal decay. Clinical studies have shown that the efficacy of sealant in caries prevention, with sealant retention being the primary factor in continued efficacy. Two major materials, composite resin and glass ionomer, are used as sealants. However, resin sealant required complicated treatment procedures, such as moisture control and acid pretreatment, etc., which render it unsuitable for use in mass dental projects, especially in rural area where dental equipment is lacking. Glass ionomer is also used as sealant. Apart from adhering to the tooth without complicated treatment procedures, it releases fluoride. In remote rural areas where dental equipment is unavailable, complete tooth surface treatment prior to sealant application is impossible. Moreover, salivary contamination on tooth surface is inevitable. Under such condition, adhering failure of the bond is generally expected. Therefore, this study attempts to find a method improving the bond strength of glass ionomer to saliva contaminated enamel. Such that, it can provide and facilitate a technical guideline for the dental health program for the child in remote areas of Taiwan. In this study, 130 human teeth were divided randomly into two groups. One was control group and the other was saliva contaminated group. Control group with cleaned enamel surfaces received without any surface treatment or with acetone, dentin conditioner, maleic acid, tartaric acid and Scotchbond primer treatment. While in saliva contaminated group, teeth received surface treatment after they were soaked in human saliva for 5 sec as they were done in control group except saliva left intact. Then, a teflon mold was fixed on the prepared enamel surface. Glass ionomer (Fuji Ⅱ, GC, Japan) was mixed according to manufactory instruction and then filled up the mold. After initial setting for 15 min, GI varnish coated on exposed glass ionomer surface. All prepared specimens were stored in distilled water at room temperature for 7 days, then tensile bond strength were tested. With stereoscope and conventional scanning electron microscope, fracture patterns were observed and classified. Low vacuum SEM was used to evaluate the stepwise effect of various surface treatment on enamel. Data were analyzed using one-way ANOVA, Tukey's studentized range test and Wilcoxon rank sums test for paired experiments and for determination of the significance of difference of tensile bond strength within and between groups. Tensile bond strength of glass ionomer to clean enamel was 2.459 ±0.786MPa. Under condition of saliva contamination, it showed significant reduction in bond strength (1.276 ±0.315MPa). Direct dried off(2.186 ±0.379MPa), maleic acid(2.795 ±0.629MPa) and Scotchbond primer(2.131 ±0.651MPa) treatment on contaminated enamel yielded significantly greater bond strengths than that obtained when saliva contamination without any surface treatment (p<0.05). However, they were comparable to the bond strength obtained when glass ionomer was bonded directly to cleaned enamel. There was no significant difference in bond strength among the three surface treatment methods, they were direct dried off, maleic acid and Scotchbond primer pretreatment. When tartaric acid and acetone were applied on the clean enamel surface, the bond strengths were reduced. The fracture patterns observed with stereoscope showed that cohesive fracture often occurred in the groups with large bond strength, and adhesive fracture were seen in the groups with small bond strength. Adhesive failure at the tooth/cement interface was observed when the bond strength was less than 1.0MPa, while mixed and cohesive failure in the cement was observed when the bond strength was greater than this value. SEM observation showed that cracks are apparent between the silica gel structure around the powder glass particles and matrix. Irregular fracture margins and fish scaled form of the glass ionomer surface were also noted. Over the mixed fracture specimen in low magnification (x30), bare enamel surface was found having residual glass ionomer in higher magnification (xl000). Wet SEM study showed that there was no remarkable difference between the clean and saliva contaminated enamel, except a thin layer of saliva and debris. Direct dried off the saliva contaminated surface did not change the enamel surface structure. Acetone may have overdrying effect with a whitish appearance over the treatment surface. It was found that enamel prism exposure under maleic acid treatment may caused by etching due to the low pH (1.18) of the acid. Tartaric acid also showed the etching effect, but not as strong as maleic acid. Residual Scotchbond primer was noted over the prepared enamel surface due to prolonged wetofthe agent, but without causing any structural alteration. Dentin conditioner was not a volatile agent which remained wet on the enamel and was not able to be observed. In conclusion, direct dried off, maleic acid or Scotchbond primer pretreatment over the saliva contaminated enamel for thirty seconds prior to glass ionomer cement placement can significantly reduce the sensitivity of saliva contamination and increase bond strength of glass ionomer to contaminated enamel surface.

碩士
高雄醫學大學
牙醫學研究所
89
英文摘要： Lasers can remove the soft dentin of decalcified zone with bacteria involved and leave the decalcified zone without bacteria involved intact. Glass ionomers have the adventage of fluoride release, strong dentin chemical adhesive ability, better marginal seal ability and good biocompatibility.This study will mainly focus on the decalcified zone without bacteria involved.If the fluoride released from the glass ionomers can support the source to remineralization,the purpose of maximun tooth structure reserved can reach.We use lasers to remove the decalicified zone,fill the cavity with glass ionomers and then analyze the element of fluoride, calcium and phosphate.At first 60 permanent teeth with no carious lesions on them are selected to cut off the root..Each tooth will be separated into two parts, buccal part and lingual part.We chose the middle 1/3 part and had 120samples.The sample was buried with Epoxy resin and polished with number 240, 400, 600, 1000 sandpapers, and then was immersed on lactic acid decalcified solution.With the area of 3.5 X3.5mm.We used diameter 1.8mm of round bur to prepare a cavity with the depth of 0.8mm. The cavity was filled with glass ionomers divided into two subgroups.The first subgroup is conventional glass ionomer.The other subgroup is hybrid-type glass ionomer.The condition of the Nd:YAG laser is 6W, 50pps, spot diameter is 0.6mm, the average energy is 83.33J/cm2.The condition of the CO2 laser is 2W,750pps,spot diameter is 0.3mm, the average energy density is 83.33J/cm2. The element of fluoride, calcium and phosphate were analyzed with EMPA and observed by SEM.On Nd:YAG laser and CO2 laser group,Fuji IX and Chem Flex glass ionomers subgroups were dectected to have the most fluoride on the teeth.The Dyract subgroup was dectected to have the least fluoride.Of all groups, on day 14, it was detected to have the most fluoride.As the calcium phosphate ratio,all groups have no statistically significant difference(p<0.001).By SEM observation,the CO2 laser groups demostrate the more bigger crates, while the Nd:YAG laser groups demostrate the more cracks,they show no significant difference on different materials and days. According to the previous study, glass ionomer can release fluoride.But on our study, we detected only small amount of fluoride on the teeth, no matter horizontal or vertical line, right or left side.Traditional glass ionomers are better than hybride-type.On calcium phosphate ratio,lactice acid group demostrate the least small value because of the calcium lost from the teeth.On day 14, traditional glass ionomers group had rising calcium phosphate ratio value.It reveal the early remineralization on the teeth. 中文摘要 1 英文摘要 4 前言 7 文獻回顧 9 (一) 雷射的物理特性及對牙齒的影響 9 1. CO2雷射 9 (1) CO2雷射的物理性質 9 (2) CO2雷射對牙釉質的影響 9 (3) CO2雷射對牙本質的影響 10 2. Nd:YAG雷射 10 (1) Nd:YAG雷射的物理性質 10 (2) Nd:YAG雷射對牙釉質的影響 10 (3) Nd:YAG雷射對牙本質的影響 11 (二) 雷射對牙髓的影響 11 (三) 牙齒組織結構與去礦化及再礦化 12 1. 牙齒組織結構 12 2. 去礦化及再礦化 13 (四) 玻璃離子體發展沿革與特性 14 1.邊緣密合度(Marginal seal ability) 14 2.氟之釋放及再吸收(Fluoride release and uptake) 15 3.牙本質鍵結能力(Dentin bond strength) 16 4.生物相容性(Biocompatibility) 16 實驗目的 17 材料與方法 18 (一) 牙齒之製備及乳酸緩衝液之泡製 18 1.牙齒之製備 18 2. 事前實驗 19 3. 乳酸脫鈣液之泡製 19 (二) 雷射之規格及能量密度計算方法 20 1. 雷射之規格 20 2. 能量密度計算方法 20 (三) 材料及分組 21 1.選用之材料 22 2.分組 22 (四) 充填後牙齒之觀察 22 1.電子微探儀(Electron Probe Microanalysis)之檢測 25 2.掃描式電子顯微鏡觀察 26 (五) 統計方法 27 結果 28 (一) 電子微探儀 28 1.氟 28 2.鈣磷比 34 (二) 掃描式電子顯微鏡 40 討論 45 (一) 材料方法方面 45 1.乳酸脫鈣液之選擇 45 2.材料與天數之選擇 46 3.實驗儀器的選擇 46 (二) 實驗結果方面 48 1.電子微探儀 48 (1)氟 48 (2)鈣磷比 52 2.掃瞄式電子顯微鏡 52 結論 55 參考文獻 56 附錄 表 圖

Emaillierte Scheiben finden seit sehr langer Zeit ihre Anwendung im Bauwesen als opake Fassadenpaneele in System- oder vorgehängten, hinterlüfteten Fassaden. Mit Mustern in Form von Punkten, Streifen oder Quadraten wird ein teilweiser Sonnen- beziehungsweise Blendschutz realisiert. Ebenso ist seit langem eine festigkeitsmindernde Wirkung einer solchen Bedruckung auf Glasbauteilen bekannt. Die Gründe dafür sind nicht geklärt, und es existieren mehrere Erklärungsversuche, die ihre Belastbarkeit aber noch nicht bewiesen haben. Ebenso beruhen die Normangaben zu bedruckten, vorgespannten Glasprodukten auf empirischen Untersuchungen ohne weitere wissenschaftliche Basis. Daher wird in dieser Arbeit das Ziel verfolgt, eine in der Fachliteratur genannte mögliche Ursache der Festigkeitsminderung genauer zu untersuchen. Neben einer Bewertung der bereits vorhandenen, wenigen Erklärungsversuche wird die in der Literatur geäußerte und auch durch Versuche im Rahmen von Qualitätskontrollen der Glasveredler berechtigte Annahme der Festigkeitsminderung auf Grund geänderter Temperaturverhältnisse während des Abkühlvorgangs durch die Emailleschicht besonders untersucht. Dieser Annahme wird mit spannungsoptischen Messmethoden und in Bruchversuchen nachgegangen. Mit Streulichtmessungen werden mögliche Veränderungen im Eigenspannungsverlauf über die Glasdicke quantitativ ermittelt. Mit Bruchversuchen in einem modifizierten Doppelring-Biegeversuch können dann unter Ansatz der ermittelten Vorspannung im Glas Rückschlüsse auf mögliche strukturelle Veränderungen der Glasoberfläche beziehungsweise größere Defekte geschlossen werden. Mittels numerischer Simulationen des Vorspannprozesses von bedruckten und unbedruckten Scheiben kann auch die Auswirkung verschiedener thermischer Ausdehnungskoeffizienten genauer bestimmt werden. In praktischen Versuchen kann eine solche mögliche Auswirkung nicht untersucht werden, da die Emaille als Überzugsmaterial als handelsübliches Produkt verwendet und nicht frei konfektioniert wird. Daher können nur die thermischen Ausdehnungskoeffizienten im Versuch berücksichtigt werden, die sich im handelsüblichen Produkt einstellen.:1 Problemstellung 1 1.1 Begriffsbestimmungen 3 1.1.1 Fachbegriffe zur Emaille 3 1.1.2 Festigkeitsbegriffe für Glas 5 1.2 Stand der Wissenschaft und Technik 7 1.2.1 Metallemaillierungen 7 1.2.2 Glasemaillierungen 8 1.3 Abgeleitete Fragestellungen 22 1.4 Lösungsansätze 23 2 Grundlagen der Werkstoffe 27 2.1 Viskosität 27 2.2 Spektrale Eigenschaften und Farbgebung 30 2.3 Glas 36 2.3.1 Mechanische Eigenschaften 36 2.3.2 Thermische Eigenschaften 37 2.4 Emaille / Glasfluss 45 2.4.1 Aufbau / Struktur / Zusammensetzung 45 2.4.2 Mechanische Eigenschaften 48 2.4.3 Thermische Eigenschaften 50 2.5 Emailliertes Glas 52 3 Thermische Vorspannung 56 3.1 Prinzip der thermischen Vorspannung 56 3.2 Mechanismus der thermischen Vorspannung 57 3.3 Mechanik der thermischen Vorspannung 60 3.3.1 Temperaturverlauf 61 3.3.2 Spannungsrelaxation 65 3.3.3 Strukturrelaxation 68 3.3.4 Zusammenfassung und Spannungsverlauf 71 4 Prüfungen und Prüfgeräte – Grundlagen 74 4.1 Optische Untersuchungen 74 4.1.1 Grundlagen der Spannungsoptik 74 4.1.2 Streulichtmessungen 75 4.1.3 Diskussion weiterer Verfahren 79 4.1.4 Anwendung Messgerät SCALP 81 4.1.5 Spektralmessung 86 4.2 Bruchversuche 87 4.2.1 Doppelring-Biegeversuche nach DIN EN 1288 88 4.2.2 Modifizierter Doppelring-Biegeversuch 90 4.2.3 Bestimmung der Versuchsgeometrie 93 4.3 Auswertung und Statistik 97 5 Prüfungen – Durchführung und Auswertung 100 5.1 Parameterzusammenstellung 100 5.2 Form und Art der Probekörper 103 5.3 Optische Untersuchungen 109 5.3.1 Überprüfung der bedruckten Seite 109 5.3.2 Differential-Refraktographie 109 5.3.3 Streulichtmessungen 110 5.3.4 Spektralmessung 117 5.3.5 Zusammenfassung optische Untersuchungen 119 5.4 Bruchversuche 120 5.4.1 Unbedruckte Proben 123 5.4.2 Schwarz bedruckte Proben 124 5.4.3 Weiß bedruckte Proben 126 5.4.4 Zusammenfassung Bruchversuche 127 5.5 Überlagerung Spannungsoptik und Bruchversuch 128 6 Numerische Simulationen 134 6.1 Simulation des Vorspannprozesses 134 6.1.1 Grundlagen 134 6.1.2 Numerische Modellierung 135 6.1.3 Temperaturprofil 137 6.1.4 Vorspannprozess für unbedrucktes Glas 140 6.1.5 Vorspannprozess für bedrucktes Glas 147 6.2 Parameterstudien 150 6.2.1 Auswirkung der Emailleschichtstärke 152 6.2.2 Auswirkung der Ausdehnungsdifferenz 155 6.2.3 Zusammenfassung numerische Simulation 158 7 Zusammenfassung und Ausblick 160 7.1 Zusammenfassung und Diskussion 160 7.2 Ausblick 170 8 Verzeichnisse 174 8.1 Bezeichnungen 174 8.1.1 Formelzeichen 174 8.1.2 Abkürzungen 177 8.2 Literaturverzeichnis 178 8.2.1 Allgemein über Glas und allgemeine Parameter178 8.2.2 Emaille 178 8.2.3 Vorspannung 180 8.2.4 Mechanik und Festigkeit 183 8.2.5 Bruchversuche und Statistik 184 8.2.6 Optik und Spannungsoptik 185 8.2.7 Normen und Richtlinien 186 8.3 Abbildungsverzeichnis 188

碩士
國立臺灣大學
臨床牙醫學研究所
90
Pit and fissure sealants has been available to the dental profession for the past two decades and the cariostatic effect has been extensively documented. The literature has reported a decrease in enamel solubility and secondary caries as well as an increased fluoride uptake by adjacent enamel. It has found that the fluoride concentration of plaque growing on or adjacent to glass ionomer cement is increased and the proportion of mutans streptococci in the plaque is reduced. A fall in plaque pH following sucrose challenge has been correlated with the dental caries increment. Therefore, measurement of the post-challenge plaque pH value and their changes can be used to evaluate an individual’s caries susceptibility. The aims of this study were to determine whether the GIC sealants have effect on the enamel fluoride contents of adjacent tooth surfaces and on the pH response of dental plaque after 10% sucrose solution challenge. Before and after GIC sealants application on four first molars, the microbiopsy technique was used to measure our twelve volunteers’ enamel fluoride content on lower canines and molars, and we recorded their plaque pH value before and within one hour changes after rinsing with 10% sucrose solution. The unstimulated whole saliva fluoride was collected before and 5, 30, 60minutes, 24, 48 hours, and 7 days after GIC sealants application for fluoride analysis.paired t test was used for comparison. The enamel fluoride concentration on the lower molar in the outer 3.5μm was increased significantly after GIC sealants application, but not on the lower canine. The saliva fluoride concentrations were significant elevated up to 48 hours after GIC sealants application. On the 7th day, the saliva fluoride level had returned to the baseline level. Resting plaque pH and the lowest pH in one hour were significantly higher than baseline values, but the mean pH drop had no significant difference between pre- and post- GIC sealant application. The results indicated that using GIC pit and fissure sealant had short term benefit to the enamel fluoride content on the same tooth, increment of saliva fluoride level within 48 hours, and reduction of the plaque acidogenic ability. But the effect of reducing individual’s caries occurrance needs more long-term clinical studies .

碩士
國立臺灣藝術大學
書畫系造形藝術碩士班
92
Color gemstone or synthetic ones are usually used for practice or creating material during the process of learning jewelry handcraft. Base on personal experiences that gemstone is rather expensive and sometimes difficult to get a suitable one for designing works. I research the materials, couch in glasses and ceramics, which are made for modeling and furthermore simulate the luster of gemstone by burn-made enamels to achieve the results. In addition, it's also easy-manufacturing and similar to practicing gemstones. At the same time make the goals with free modeling and lower costs. This research is by the method of experiments and relevant documents about enamels to distinguish traditional from modern way of enamel manufacture, and then probe into its feasibility and developmentally. The experiment, firing enamels on glasses, records the relationship between burning temperature and the variation of glass state of sodium-calcium glass and lead glass, so as to know each model's time and temperature and moreover to know if these firing enamels could be used for practice materials of jewelry hand-craft. The other experiment, firing enamels on ceramics, records 9 kind sizes of ceramics, to see whether it could support the temperate changes of quickly firing enamels and observes the effect from different ceramic bottoms. And induce how the convenience of color expression by enamel and modeling bottom by ceramic, and the feasibility of substituting enamel for jewelry when practice. The conclusion of this research, we indeed knowing that is workable to substitute or to be materials for jewelry hand-craft, moreover glasses and ceramics are quite cheap and easy to manufacture, so that we can give them up without heartache and re-manufacture them during practice smalto and for learning and practicing, and it is also a good auxiliary teaching material. Furthermore glass-bottom provides with excellent ability on pervious to light and it makes better effect for simulating gemstone. Via painting on enamel and arranging to model, it shows another more special style and effect on art creating.

The aim of this project is the study of the painting techniques applied on stained glass, namely blue enamels, sanguine red and grisaille. The research and interpretation of several historical treatises dated to between the 12th and the 18th centuries was performed, with a study of the production technology of the selected painting techniques, from the preparation of the pigment to the preparation of the paint. With this in mind, selected raw materials used in the productions of blue enamels were characterized, followed by the reproduction of selected historical recipes of blue enamels, sanguine red and grisaille. Parameters such as firing temperature, grinding and binding agents used to apply the paint on glass were considered. The methodology selected was based on the chemical and morphological characterization of both reproduced powder and paint samples by means of a multi-analytical approach. In addition to the reproduction of the selected painting techniques, corrosion studies of blue enamel powder and paint samples were performed in order to provide new insights on the corrosions mechanisms involved. The results obtained were compared with selected painted stained-glass fragments from Portuguese collections, mainly the ones located in Batalha Monastery, Charola from Convento de Cristo in Tomar and Pena National Palace in Sintra. The present study concluded that the choice of the raw materials to the production of the paint, the binder used to apply the paint, and parameters such as firing temperature and heating rate, had an impact on the outcome, resulting on a better adhesion of the paint layer to the base glass. The use of zaffer as a colouring agent does not allow determination of the outcome of the paint, while adding powdered glass such as smalt gives to the glass painter the opportunity to know the final result before firing. As for sanguine red paint, it is concluded that the final outcome of the paint is strongly influenced by the heating rate. In addition, the use of gum arabic as a binder, or in the pigment itself, provides a better adhesion of the paint layer to the base glass. Regarding the grisaille painting, the main differences between the recipes lay on the composition of the lead-based glass and on the ratios between this and the colouring agents. Furthermore, it was also possible to conclude that there is an evolution of the morphology of the grisailles towards a higher homogeneity of the surface. The corrosion studies performed on blue enamels allowed to conclude that with the lixiviation of the alkaline components of the enamel, cobalt will be influenced by other neighbouring ions, leading to a change of colour. In some cases, Pb2+ ions may also be the responsible for this colour change, with the formation of lead white. The results obtained were in a good agreement with the characterization of the selected case studies, evidencing the importance of the intersection between the written sources and the laboratory work.

As Resinas compostas sofreram modificações através da introdução de matérias bioindutores na sua matriz, tais como micropartículas de vidro bioativo (BAG). Compósitos que contenham este tipo de materiais são denominados de resinas iónicas, permitindo uma troca de iões entre o material restaurador e o tecido dentário. As resinas iónicas são um novo material que combina as propriedades físicas dos compósitos e características bioativas dos ionómeros de vidro, nomeadamente a libertação de iões de flúor em maior quantidade que os ionómeros de vidro e adicionalmente libertam também iões de cálcio e fosfato. Em Odontopediatria estes materiais possibilitam uma diminuição na execução de tratamentos mais invasivos, graças às suas características bioativas que podem estimular a produção de tecido e melhorar a qualidade do tecido remanescente. Com a presente revisão bibliográfica pretende-se abordar a importância dos materiais restauradores na medicina dentária e a maneira como as suas características têm sido aprimoradas fazendo face às necessidades atuais, melhorando a estética, mecânica e biocompatibilidade.
Composite resins have undergone modifications through the introduction of bioinductive materials in their matrix, such as bioactive glass (BAG) microparticles. Composites containing this type of material are called ionic resins, allowing an exchange of ions between the restorative material and dental tissue. Ionic resins are a new material that combines the physical properties of composites and bioactive characteristics of glass ionomers, namely the release of fluoride ions in greater quantities than Glass Ionomer cements and additionally also release calcium and phosphate ions. In Pediatric Dentistry, this allows a decrease in the execution of more invasive treatments, duo to its bioactive characteristics that can stimulate the production of tissue and improve the quality of the remaining tissue. This bibliographic review aims to address the importance of restorative materials in dentistry and the way in which their characteristics have been improved addressing current needs, improving aesthetics, mechanics, and biocompatibility.