This research explores a novel in-situ technique for monitoring film thickness in the reactive etching process that incorporates a micromachined sensor. The sensor correlates film thickness with changes in resonant frequency that occurs in the micromachined platform during etching. The sensor consists of a platform that is suspended over drive and sense electrodes on the surface of the substrate. As material is etched from the platform, its resonant vibrational frequency shifts by an amount that is proportional to the amount of material etched, allowing etch rate to be inferred. This RIE monitoring methodology exploits the accuracy of resonant micromechanical structures, whereby shifts in the fundamental resonant frequency measure a physical parameter. A majority of these systems require free-standing mechanical movement and utilize a sacrificial layer process as the key technique to develop and release the structure on a substrate. A sacrificial layer technique that incorporates a low temperature sacrificial polymer was utilized to develop and release the suspended RIE sensor with excellent performance and is capable of fabricating other low cost, high performance and reliable suspended MEMS devices. The integration of sensors and electronic circuitry is a dominant trend in the semiconductor industry, and much work and research has been devoted to this effort. The RIE sensor relies on capacitive transduction to detect small capacitance changes and the resulting change in resonant frequency during the RIE process. The RIE sensor's overall performance is limited by the interface circuit, and integration with the proper circuit allows the RIE sensor to function as a highly sensitive measure of etch rate during the RIE process. A capacitive feedback charge amplifier interface circuit, when configured with the RIE senor at the input achieves very low noise sensing of capacitance changes and offers the potential for wide dynamic range and high sensitivity. As an application vehicle, process control was demonstrated in the PlasmaTherm SLR series RIE system located in the Georgia Tech Microelectronics Research Center.

There is an understanding of surface photovoltage (SPV) behavior for GaN, yet little is known about the SPV behavior for AlGaN. In this work, a Kelvin probe was used to measure the SPV for p-type AlGaN. Very slow SPV transients were found in AlGaN, which could not be explained with a simple thermionic model. A possible explanation of this behavior is the segregation of impurities to the surface, which causes significant reduction of the depletion region width (down to 2 nm), with carrier tunneling and hopping becoming the dominant mechanisms responsible for the SPV transients. To verify this assumption, the near-surface defective region (about 40 nm) has been removed through the ICP-RIE process. After the etching, the SPV transients became fast and increased in magnitude by about 0.6 eV. By using the thermionic model, band bending was estimated to be -1 eV.

Made available in DSpace on 2015-04-14T13:29:14Z (GMT). No. of bitstreams: 1 399354.pdf: 7916796 bytes, checksum: 52f9942a655db745c4d2a97dff7dead8 (MD5) Previous issue date: 2007-12-12 / Artigo 1 - Aim: The aim of this in vitro study was to investigate the effect of Nd:YAG and argon laser irradiations on the enamel acid demineralization by two different chemical laboratory models (pH cycling).Summary background data: The use of lasers to prevent enamel caries has been shown good results, but there are few comparative studies about the effect of different lasers in different pH models cycling.Methods and materials: Twenty one extracted human third molars were sectioned into tooth quarters. The quarters were distributed in three groups: GROUP I (control), non-treated; GROUP II received the Nd:YAG laser irradiation with the following protocol: 60 mJ, 15 pps, 0.9 W e 47.77 J/cm2, 30 seconds; and GROUP III received the argon laser irradiation with the following protocol: 250 mW, 12 J/cm2, 48 seconds. The surfaces were covered with an acid resistent varnish to be immersed in standard acidfied buffer solutions. The tooth quarters were submitted to a two different pH cycling: cycle 1: a 14-day remineralization (6 hours) and demineralization (18 hours) solutions, 37?C; cycle 2 with 48 hours in demineralization solution. The samples were prepared in slices (60 to 100 &#956;m) to be evaluated by polarized light microscopy. The demineralizations areas were measured (mm2) (n=11). Results: Means followed by different letters are significantly different to ANOVA and Tukey s test (p<0,05): 0.2509 A (control cycle 2); 0.1836 AB (control cycle 1); 0.1782 AB (Nd:YAG cycle 1); 0.1391 BC (argon cycle 2); 0.0927 BC (Nd:YAG cycle 2) e 0.0682 C (argon cycle 1). Conclusion:The results suggest that the treatment with argon laser was more effective, showing the smaller demineralization area by two different pH model cycling. Artigo 2 - Aim: The aim of this in vitro study was to investigate the effect of Nd:YAG and argon laser irradiations on the enamel acid demineralization by a chemical laboratory model to simulate acid erosion lesions.Summary background data: Erosive lesions in enamel are frequently found in patients with gastric-alimentary disturbs. There are no studies examining the use of lasers to prevent enamel erosions.Methods and materials: Third extracted human third molars were sectioned into tooth quarters. The quarters were distributed in three groups: GROUP I (control), non-treated; GROUP II received the Nd:YAG laser irradiation with the following protocol: 60 mJ, 15 pps, 0.9 W e 47.77 J/cm2, 30 seconds; and GROUP III received the argon laser irradiation with the following protocol: 250 mW, 12 J/cm2, 48 seconds. The surfaces were covered with an acid resistent varnish to be immersed in standard acidfied buffer solutions. The tooth quarters were submitted to a pH cycling: 14-day remineralization (6 hours) and demineralization (pH 2,5 - 18 hours) solutions, 37?C. The samples were prepared in slices (60 to 100 &#956;m) to be evaluated by polarized light microscopy. The demineralizations depths were mesured in mm (n=21). Results: Means followed by different letters are significantly different to ANOVA and Tukey s test (p<0,05): 0.1881 A (control occlusal); 0.1867 A (control cervical); 0.1610 B (argon occlusal); 0.1576 B (argon cervical); 0.1529 B (Nd:YAG occlusal); 0.1481 B (Nd:YAG cervical). Conclusions: The results suggest that the treatment with lasers increased the enamel acid demineralization resistance, so it can be indicated to prevent gastric-alimentary disturbs. / Artigo 1 - Objetivo: O objetivo deste trabalho foi avaliar a ?rea de desmineraliza??o do esmalte irradiado com os lasers de Nd:YAG ou arg?nio, al?m de investigar dois m?todos de ciclagem de pH que simulam o desenvolvimento da doen?a c?rie.Problema: O uso dos lasers na preven??o de c?rie em esmalte tem sido pesquisado, mostrando bons resultados principalmente quando associados ao fl?or. Todavia, poucos estudos comparativos acerca do uso de lasers sobre o esmalte em diferentes ciclos de pH est?o dispon?veis.Materiais e m?todos: Vinte e um terceiros molares humanos inclusos extra?dos tiveram a por??o coron?ria seccionada em duas faces, vestibular e lingual; que, posteriormente, foram seccionadas em duas hemifaces. Os fragmentos foram distribu?dos aleatoriamente em tr?s grupos: o GRUPO I, de controle, n?o recebeu qualquer tratamento; o GRUPO II foi tratado com laser de Nd:YAG com 60 mJ, 15 pps, 0,9 W e 47,77 J/cm2, por 30 segundos; e, enfim, o GRUPO III tratado com laser de arg?nio com 250 mW, 12 J/cm2, por 48 segundos. Ap?s, as hemifaces de cada grupo tiveram a superf?cie de esmalte coberta com verniz, restando uma ?rea central de 3 mm x 3 mm, a qual foi exposta a um dos seguintes ciclos de pH: ciclo 1, compreendendo 14 dias de imers?o em solu??o desmineralizante por 6 horas/dia e solu??o remineralizante por 18 horas/dia a 37?C; ciclo 2, com 48 horas de imers?o em solu??o desmineralizante. As hemifaces foram cortadas em fatias com espessura de 60 a 100 &#956;m para obten??o das l?minas histol?gicas. Em seguida, foram observadas em microscopia de luz polarizada para medi??o das ?reas de desmineraliza??o (mm2) (n=11 por grupo). As m?dias obtidas foram: 0,2509 A (controle ciclo 2); 0,1836 AB (controle ciclo 1); 0,1782 AB (Nd:YAG ciclo 1); 0,1391 BC (arg?nio ciclo 2); 0,0927 BC (Nd:YAG ciclo 2) e 0,0682 C (arg?nio ciclo 1). M?dias seguidas de letras distintas apresentam diferen?a estat?stica para ANOVA e Tukey (p<0,05). Foi poss?vel concluir que o tratamento com o laser de arg?nio foi mais efetivo, apresentando uma menor ?rea de desmineraliza??o, sob a ciclagem de pH de 14 dias. Artigo 2 - Objetivo: O objetivo deste trabalho consistiu em avaliar a profundidade de desmineraliza??o do esmalte, nas paredes cervical e oclusal, ap?s a aplica??o dos lasers de Nd:YAG e arg?nio.Problema: Les?es erosivas s?o comuns em indiv?duos com dist?rbios gastro-alimentares e podem levar ? perda do esmalte dental. N?o h? relatos na literatura do uso de lasers como um tratamento preventivo desta situa??o cl?nica.Materiais e m?todos: Trinta terceiros molares extra?dos tiveram as coroas seccionadas em duas partes, vestibular e lingual; sendo cada face vestibular e cada face lingual seccionada no sentido oclusocervical, no centro da face, obtendo-se 4 hemifaces, as quais foram distribu?das em tr?s grupos: o, GRUPO I, de controle, que n?o recebeu qualquer tratamento; o GRUPO II, tratado com o laser de Nd:YAG com 60 mJ, 15 pps, 0,9 W e 47,77 J/cm2, por 30 segundos; e, enfim, o GRUPO III, tratado com o laser de arg?nio com 250 mW, 12 J/cm2, por 48 segundos. Ap?s a aplica??o dos lasers, os fragmentos foram submetidos ? ciclagem de pH 2,5 por 14 dias. Em seguida, foram obtidas l?minas histol?gicas de 60 a 100 &#956;m para serem observadas em microsc?pio ?ptico de luz polarizada (n=21 por grupo). A profundidade de desmineraliza??o foi mensurada (mm) e os resultados m?dios obtidos foram: 0,1881 A (controle oclusal); 0,1867 A (controle cervical); 0,1610 B (arg?nio oclusal); 0,1576 B (arg?nio cervical); 0,1529 B (Nd:YAG oclusal); 0,1481 B (Nd:YAG cervical). M?dias seguidas de letras distintas apresentam diferen?a estat?stica para ANOVA e Tukey (p<0,05). Foi poss?vel concluir que o tratamento com os lasers aumentou a resist?ncia do esmalte ao ?cido, podendo ser empregado como m?todo preventivo frente a dist?rbios gastro-alimentares. Al?m disso, n?o houve diferen?a na profundidade de desmineraliza??o do esmalte nas paredes cervical e oclusal.

Ce travail de thèse porte sur des composants à cristaux photoniques (CP) bidimensionnels réalisés dans des matériaux à base d'InP pour un fonctionnement dans le domaine 1,55 µm. Au sein du CP, la périodicité de la constante diélectrique génère une bande interdite photonique, domaine de fréquence dans lequel la propagation des modes optiques est interdite. L'introduction de défauts dans le CP permet à certains modes optiques localisés d'exister. De telles structures peuvent alors être utilisées comme brique élémentaire d'un circuit intégré photonique. Nous avons étudié des adaptateurs de mode et des lasers monofréquences ainsi que des guides d'onde sur membrane InP.<br /><br /> Les CP sont ici un réseau de trous fabriqués à l'aide de la gravure ionique réactive associée à un plasma à couplage inductif. Dans un plasma Cl2/Ar optimisé, nous avons obtenu une profondeur de gravure de 2,9 µm pour des trous de 250 nm diamètre. Nous avons montré que la présence de N2 dans un plasma contenant du chlore renforce la gravure anisotrope et supprime la rugosité des surfaces gravées, et que l'addition de BCl3 permet d'augmenter la verticalité des trous. Le plasma BCl3/N2 a permis d'obtenir les meilleurs profils et états de surface et une profondeur gravée de 1 µm.<br /><br /> Plusieurs géométries d'adaptateurs de mode à CP ont été étudiées et leurs spectres de transmission ainsi que la divergence du mode émergent ont été caractérisés et comparés avec les résultats de simulation. La meilleure géométrie conduit à une amélioration de l'efficacité de transmission d'un facteur 4. Les guides W1 sur membrane InP présentent des pertes de propagation de 25 dB/cm pour des fréquences situées sous la ligne de lumière.

The subject of this thesis is a new chip to substrate interconnection technique using self-aligning elastic chip sockets. This work was focused on the technology steps which are necessary to fulfill in order to realize the suggested technique. Elastic chip sockets offer a solution for several assembly and packaging challenges, such a thermo-mechanical mismatch, effortless rework, environmental compatibility, high interconnection density, high frequency signal integrity, etc. Two of the most challenging technology aspects, metallization and etching of the silicone elastomer were studied, but also, air bubble free casting of the silicone elastomer was taken into consideration. Elastic chip sockets and single elastic micro-bump contacts of different shapes and sizes were manufactured and characterized. The contact resistance measurements revealed that the elastic micro-bump contacts manufactured by using the developed methods require less than one tenth of the contact force to achieve the same low contact resistance as compared to commercial elastic interconnection structures. The analysis and measurements of the high frequency properties of the elastic micro-bump structures have shown that they can operate up to several tens of GHz without a serious degradation of the signal quality. The same methods were applied to manufacture very high density contact area array (approximately 80000 connections/cm2), which until now was achieved only using so called chip-first techniques. The low contact resistance, the absence of environmentally harmful materials, no need of soldering, easy rework as well as capability of very high interconnecting density and very high frequency compatibility, indicates a high potential of this technique for assembly and packaging. Moreover, the presented technology of the silicone elastomer micromachining (metallization and RIE in particular) can be used for manufacturing of other microstructures, like chemical or biological micro reactors. / QC 20110114

The electro-optical properties of the ZnO/Si heterojunction embedded with self-assembled gold nanoparticles on patterned silicon substrate are investigated in this master thesis. High quality n-type ZnO film is deposited on patterned p-type silicon substrate by radio-frequency sputtering to form a ZnO/Si pn junction. The patterned silicon substrates are prepared by ICP-RIE using self-assembled nickel metal dot and silicon dioxide as etching mask. The optimum ICP process conditions of silicon nanopillars are CF4/Ar ~ 40/40 sccm and bias/RF power 400/400 W. Silicon nanopillars of diameter ~ 50 nm and height 100~400 nm are formed on the substrate surface. ZnO film is then deposited of a growth rate ~ 12 nm/min at the substrate temperature = 200oC. The plasmonic effects on the electro-optical properties, including photoluminescence (PL), reflection, and electrical characteristics, are studied by adding self-assembled gold nanoparticles within the ZnO film. The self-assembled gold nanoparticles are formed by thermal deposition and rapid thermal annealing at 700oC. The gold nanoparticles are observed by scanning electron microscopy (SEM) and particles of diameter about 100 nm. The PL intensity of ZnO is enhanced more than ten times at the peak wavelength = 380 nm by adding the gold nanoparticles and silicon nanopillars. Strong blue emission light could be saw with the naked eyes. For the electric characteristics, self-assembled gold nanoparticles in patterned ZnO/Si heterojunction show photoelectric conversion phenomenon because of high electromagnetic absorption and plasmonic effects.

<p>The subject of this thesis is a new chip to substrate interconnection technique using self-aligning elastic chip sockets. This work was focused on the technology steps which are necessary to fulfill in order to realize the suggested technique. Elastic chip sockets offer a solution for several assembly and packaging challenges, such a thermo-mechanical mismatch, effortless rework, environmental compatibility, high interconnection density, high frequency signal integrity, etc.</p><p>Two of the most challenging technology aspects, metallization and etching of the silicone elastomer were studied, but also, air bubble free casting of the silicone elastomer was taken into consideration. Elastic chip sockets and single elastic micro-bump contacts of different shapes and sizes were manufactured and characterized.</p><p>The contact resistance measurements revealed that the elastic micro-bump contacts manufactured by using the developed methods require less than one tenth of the contact force to achieve the same low contact resistance as compared to commercial elastic interconnection structures.</p><p>The analysis and measurements of the high frequency properties of the elastic micro-bump structures have shown that they can operate up to several tens of GHz without a serious degradation of the signal quality.</p><p>The same methods were applied to manufacture very high density contact area array (approximately 80000 connections/cm2), which until now was achieved only using so called chip-first techniques.</p><p>The low contact resistance, the absence of environmentally harmful materials, no need of soldering, easy rework as well as capability of very high interconnecting density and very high frequency compatibility, indicates a high potential of this technique for assembly and packaging.</p><p>Moreover, the presented technology of the silicone elastomer micromachining (metallization and RIE in particular) can be used for manufacturing of other microstructures, like chemical or biological micro reactors.</p>

The research presented in this dissertation explores the possibility of using colloidal indium tin oxide (ITO) nanoparticle solutions to direct write transparent conducting coatings (TCCs), as an alternative route for TCC fabrication. ITO nanoparticles with narrow size distribution of 5-7 nm were synthesized using a non-aqueous synthesis technique, and fabricated into films using spin coating on substrates made from glass and fused quartz. The as-coated films were very transparent (>95% transmittance), but highly resistive, with sheet resistances around 10¹³ Ω/sq . Pre-annealing plasma treatments were investigated in order to improve the electrical properties while avoiding high temperature treatments. Composite RIE treatment recipes consisting of alternating RIE treatments in O₂ plasma and in Ar plasma were able to reduce the sheet resistance of as spin coated ITO films by 4-5 orders of magnitude, from about 10¹³ Ω/sq in as-coated films to about 3 x 10⁸ Ω/sq without any annealing. Plasma treatment, in combination with annealing treatments were able to decrease the sheet resistance by 8-9 orders of magnitude down to almost 10 kΩ/sq , equivalent to bulk resistivity of ~0.67 Ω.cm. Investigation into effectiveness of various RIE parameters in removing residual organics and in reducing the sheet resistance of colloidal ITO films suggested that while reactive ion annealing (RIE) pressure is an important parameter; parameters like plasma power, number of alternating O₂-Ar RIE cycles were also effective in reducing the residual organic content. Impedance spectroscopy analysis of the colloidal ITO films indicated the dominance of the various interfaces, such as grain boundaries, insulating secondary phases, charge traps, and others in determining the observed electrical properties.

Submitted by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-01-23T16:14:43Z No. of bitstreams: 5 isabella.pdf: 2438155 bytes, checksum: 8849537d67c505387dbeb111a0c0a616 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2015-02-10T11:06:43Z (GMT) No. of bitstreams: 5 isabella.pdf: 2438155 bytes, checksum: 8849537d67c505387dbeb111a0c0a616 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) / Made available in DSpace on 2015-02-10T11:06:43Z (GMT). No. of bitstreams: 5 isabella.pdf: 2438155 bytes, checksum: 8849537d67c505387dbeb111a0c0a616 (MD5) license_url: 52 bytes, checksum: 3d480ae6c91e310daba2020f8787d6f9 (MD5) license_text: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) license.txt: 2109 bytes, checksum: aa477231e840f304454a16eb85a9235f (MD5) Previous issue date: 2013 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / O transtorno de d?ficit de aten??o e hiperatividade (TDAH) ? o dist?rbio de desenvolvimento mais comum entre os escolares, podendo desencadear altera??es em toda a trajet?ria de vida do indiv?duo e de seus familiares. Objetivos: Investigar se o TDAH pode ser considerado fator de risco para altera??es bucais. Metodologia: A disserta??o foi desenvolvida em dois estudos independentes. No primeiro estudo foi desenvolvido um artigo de revis?o em que dois pesquisadores realizaram as buscas, de forma independente, nas bases de dados MEDLINE e Web of Science. Foram analisados todos os artigos originais sobre o tema, independente do tipo de estudo, publicados desde o in?cio do banco de dados at? agosto de 2012. Estudos de revis?es foram exclu?dos. No segundo estudo foi desenvolvido uma pesquisa transversal com amostra representativa de 851 crian?as com idades entre 7 e 12 anos, selecionadas aleatoriamente nas escolas da cidade de Diamantina. Informa??es socioecon?micas foram coletadas atrav?s de question?rios enviados aos pais das crian?as. Todas as crian?as participaram do exame cl?nico de c?rie dent?ria e da avalia??o neuropsicol?gica utilizando o teste das Matrizes Progressivas Coloridas de Raven, Cubos de Corsi e Digit Span. Os sintomas de desaten??o e hiperatividade foram investigados pelo preenchimento da escala SNAP pelos pais e professores. Resultados: No estudo de revis?o, os resultados foram divergentes com rela??o ? associa??o entre TDAH e sa?de bucal, sendo que cinco estudos encontraram associa??o entre c?rie dent?ria e TDAH, no entanto, dois n?o estabeleceram essa associa??o. Em rela??o, a associa??o entre trauma dent?rio e TDAH, cinco estudos encontraram associa??o positiva, enquanto outros 3 n?o encontraram associa??o. E, somente um estudo mostrou associa??o entre c?rie dent?ria e gengivite. A maioria dos estudos existentes apresentaram limita??es metodol?gicas, tais como n?o padroniza??o dos crit?rios diagn?sticos para o TDAH, aus?ncia de c?lculo amostral e falta de representatividade amostral. No segundo estudo da disserta??o, crian?as relatadas como desatentas e/ou hiperativas pelos pais apresentaram maior probabilidade de possuir dentes cavitados. Maior escolaridade materna e melhor desempenho no subteste Cubos de Corsi (ordem inversa) foram fatores protetores em rela??o ? ocorr?ncia de c?rie dent?ria. Conclus?o: O estudo de revis?o indicou que n?o h? consenso sobre a associa??o entre TDAH e sa?de bucal, por?m, a maioria das evid?ncias indicam a favor da exist?ncia dessa associa??o. Os dados do artigo original revelaram que a escolaridade materna, desaten??o e hiperatividade relatadas pelos pais e o desempenho nas fun??es executivas foram as vari?veis explicativas para a ocorr?ncia de dentes cavitados. / ABSTRACT The attention deficit and hyperactivity disorder (ADHD) is the most common developmental disorder among students and may trigger changes across the life course of the individuals and their families. Objectives: To investigate whether ADHD can be considered a risk factor for oral alterations. Methods: The dissertation was developed in two independent studies. In the first study, a review article was developed in which two researchers conducted the searches independently, in the MEDLINE and Web of Science databases. We analyzed all original articles on the subject, regardless the type of the study, published since the beginning of the database to August 2012. In the second study we developed a cross-sectional study with a representative sample of 851 children aged between 7 and 12 years, randomly selected from schools of Diamantina city. Socioeconomic data were collected through questionnaires sent to parents. All children participated in the clinical examination of dental caries and neuropsychological assessment, using the Raven Coloured Progressive Matrices test, Corsi Blocks and Digit Span. Inattention and hyperactivity symptoms were assessed by the filling of the SNAP scale by parents and teachers. Results: In the first study, the results were conflicting regarding the association between ADHD and oral health. Five studies found an association between dental caries and ADHD, however two have not established this association. Regarding the association between dental trauma and ADHD, five studies found a positive association, while 3 others found no association. And, only one study showed an association between dental caries and gingivitis. Most existing studies had methodological limitations, such as non-standardization of the diagnostic criteria for ADHD, no sample size calculation and lack of representativeness. In the second study of this dissertation, children reported as inattentive and / or hyperactive by their parents were more likely to have cavitary teeth. Higher maternal education and better performance on the Corsi Blocks subtest (backward) were protective factors to dental caries. Conclusion: The review study indicated that there is no consensus about the association between ADHD and oral health, but most evidences point to the existence of this association. The data of the original article revealed that maternal education, inattention and hyperactivity reported by parents and performance in executive functions were the explanatory variables for the occurrence of dental caries.

?rea de concentra??o: Odontopediatria. / Linha de pesquisa: Epidemiologia e controle das doen?as bucais. / Na Ficha catalogr?fica e Folha de aprova??o consta o t?tulo: "Incid?ncia da c?rie dent?ria severa em pr?-escolares e fatores de risco maternos: uma coorte prospectiva de tr?s anos". / Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2018-04-03T17:50:03Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) rafaela_lopes_gomes.pdf: 1670445 bytes, checksum: d0f7108015dd1c92d5443cae75a82475 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2018-04-09T18:43:02Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) rafaela_lopes_gomes.pdf: 1670445 bytes, checksum: d0f7108015dd1c92d5443cae75a82475 (MD5) / Made available in DSpace on 2018-04-09T18:43:02Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) rafaela_lopes_gomes.pdf: 1670445 bytes, checksum: d0f7108015dd1c92d5443cae75a82475 (MD5) Previous issue date: 2017 / Universidade Federal dos Vales do Jequitinhonha e Mucuri (UFVJM) / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Objetivo: Avaliar a associa??o entre fatores de risco maternos e a incid?ncia de les?o severa de c?rie dent?ria em crian?as pr?-escolares. Metodologia: O estudo foi realizado com 158 pares de m?es e crian?as de um a tr?s anos de idade que participaram de um estudo transversal realizado no ano de 2014 na cidade de Diamantina, MG. Ap?s tr?s anos, as crian?as foram divididas em dois grupos de acordo com a exposi??o e reexaminadas para verificar novos casos de les?es severas de c?rie dent?ria. O grupo exposi??o foi composto por crian?as filhas de m?es com c?rie dent?ria n?o tratada no primeiro exame (n=79) e as crian?as filhas de m?es livres de c?rie ou com c?rie tratada no primeiro exame formaram o grupo n?o exposto (n=79). A an?lise dos dados foi realizada utilizando-se o programa Statistical Package for the Social Sciences (SPSS) para Windows, vers?o 22.0 e incluiu a descri??o de frequ?ncia das vari?veis, teste qui-quadrado de Pearson e regress?o de Poisson (an?lise hier?rquica). Resultados: Cento e quarenta crian?as e suas m?es completaram o estudo. A an?lise de regress?o de Poisson n?o ajustada mostrou que escolaridade materna (p=0,002), renda mensal familiar (p=0,022), placa vis?vel na m?e (p<0,001), idade da crian?a aos dois (p=0,009) e aos tr?s anos (p=0,032), placa vis?vel na crian?a (p=0,001), atividade de c?rie na crian?a (p<0,001), presen?a de c?rie dent?ria no baseline (p<0,001), c?rie cavitada no baseline (p<0,001) e a n?o ades?o ao tratamento (p<0,001) foram fatores de risco para o desenvolvimento de novas les?es de c?rie dent?ria severa. No modelo final, escolaridade materna (RR = 2,02; IC95%: 1,06-3,88; p= 0,034), placa vis?vel na m?e (RR = 1,84; IC95%: 1,22-2,76; p = 0,004) e c?rie cavitada da crian?a no baseline (RR = 2,26; IC95%: 1,52-3,37; p<0,001) permaneceram como fatores de risco para incid?ncia de les?es severas de c?rie dent?ria. Conclus?o: Escolaridade materna menor do que nove anos de estudo, placa vis?vel na m?e e les?o cavitada de c?rie dent?ria na primeira inf?ncia foram fatores de risco para incid?ncia de c?rie severa ap?s tr?s anos de acompanhamento. / Disserta??o (Mestrado) ? Programa de P?s-Gradua??o em Odontologia, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2017. / Objective: To evaluate the association between maternal risk factors and the incidence of severe caries lesions in preschool children. Methodology: The study was conducted with 158 pairs of mothers and children from one to three years of age who participated in a cross-sectional study conducted in 2014 in the city of Diamantina, MG. After three years, the children were divided into two groups according to exposure and reexamined to verify new cases of severe caries lesions. The exposure group consisted of children of mothers who had untreated dental caries on the first exam (n = 79). Children whose mothers did not have untreated caries on the first examination formed the not-exposed group (n = 79). Data analysis was performed using the Statistical Package for Social Sciences (SPSS) for Windows, version 22.0 and included the description of the variables' frequency, Pearson's chi-square test, and Poisson regression (hierarchical analysis). Results: One hundred and forty children and their mothers completed the study. The unadjusted Poisson regression analysis showed that maternal schooling (p = 0.002), monthly family income (p = 0.022), visible plaque in the mother (p <0.001), child age at two (p = 0.009) and three (P = 0.032), visible plaque in the child (p = 0.001), dental caries activity in the child (p <0.001), presence of dental caries in the baseline (p <0.001), cavitated dental caries in the baseline (p <0.001) and not adhering to treatment (p <0.001) were risk factors for the development of new severe caries lesions. In the final model, maternal schooling (RR = 2.02, 95% CI:1.06-3.88, p = 0.034), visible plaque in the mother (RR = 1.84, 95% CI: 1.22-2.76,p = 0.004) and cavitated caries in children at the baseline (RR = 2.26, 95% CI: 1.52-3.37, p <0.001) remained as risk factors for the incidence of severe dental caries lesions. Conclusion: Maternal schooling lower than nine years, visible plaque in the mother and cavitated dental caries lesion in early childhood were risk factors for severe caries after three years of follow-up.