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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
491

Laser de CO2 como auxiliar na remoção de bráquetes estéticos cerâmicos / CO2 laser-assisted debonding for esthetic ceramic brackets

Rodrigo Teixeira Macri 02 May 2012 (has links)
Este estudo avaliou a eficiência do uso do laser de CO2 com comprimento de onda de 10,6 m como auxiliar na remoção de bráquetes estéticos cerâmicos. Para este estudo foram utilizados 105 pré-molares inferiores humanos recentemente extraídos, que receberam irradiações com laser de CO2 antes da descolagem dos bráquetes. Na primeira fase deste estudo, o objetivo foi mensurar e comparar a temperatura no compósito de colagem do bráquete e na câmara pulpar após aplicação do laser de CO2 , para observar a segurança para o esmalte, bem como se a temperatura era suficiente para fragilizar o compósito, facilitando a remoção do bráquete. Nesta etapa foram utilizados 30 pré-molares inferiores recentemente extraídos, sendo que cada um recebeu 4 irradiações com diferentes protocolos de maneira aleatória. Foram testados 12 diferentes protocolos variando o tempo de irradiação (3 e 5s), a duração do pulso (0,01 e 0,03s) e a potência (5, 8 e 10W). Cada protocolo foi utilizado por 10 vezes (n=10), totalizando 120 irradiações. Em todas as irradiações os corpos-de-prova foram imersos em banho térmico com água a 37º C. Foram encontrados 4 protocolos cuja variação da temperatura na polpa foi menor que 5,5º C, portanto compatível com a saúde da polpa. Na segunda etapa do estudo, o objetivo foi avaliar a resistência ao cisalhamento após a aplicação do laser utilizando os protocolos cuja temperatura na polpa não fosse superior a 5,5º C. Setenta e cinco pré-molares inferiores humanos foram divididos em 5 grupos, dos quais um não foi submetido à irradiação, sendo considerado Controle (C). Nos 4 grupos restantes, irradiações foram realizadas como descrito a seguir: Grupo I (potência 5W; tempo de pulso 0,01s; tempo de aplicação 3s), Grupo II (5W; 0,03s e 3s), Grupo III (8W; 0,01s e 3s) e Grupo IV (10W; 0,01s e 3s). Cada grupo foi formado por 15 corpos-de-prova (n=15). Após a descolagem do bráquete foi avaliado o Índice de Remanescente Adesivo (IRA). Após as mensurações e aplicação da Análise de Variância (ANOVA) e do teste de Tukey foi constatado que o único grupo que apresentou diminuição na força de remoção foi o IV (7,33 MPa) em relação ao grupo C (10,81 MPa) sendo assim considerado seguro e eficaz na diminuição da resistência do compósito. / This study evaluates the efficacy CO2 10,6 m laser-assisted debonding esthetic ceramic brackets. For this purpose it was used 105 recently extracted lower human premolars that were irradiated with CO2 laser before debonding. In the first phase, the objectives were to measure and compare the temperature in composite for bracket bonding and at the pulp chamber after CO2 laser irradiation, to observe the safety for enamel, as well the temperature was enough to softening the composite, making debonding bracket easier. In this part it was used 30 lower premolar recently extracted, and each one received 4 irradiations with different protocols, randomly choose. It was tested 12 different protocols varying time of irradiation (3 and 5s), pulse duration (0,01s e 0,03s) and power (5, 8 and 10W). Each protocol was repeated for 10 times (n=10), resulting 120 irradiations. In every irradiation the teeth tested were immerse in warm water bath at 37o C. It was found 4 protocols with pulp temperature lower than 5,5º C, so this is compatible with pulp health. In the second phase of this study, the objective was to evaluate the shear bond strength after laser irradiation, using the protocols with pulp chamber temperatures lower than 5,5º C. Seventy-five lower human premolars was shared in 5 groups. One group did not receive laser irradiation and considered Control (C) and the other groups the irradiation was made as it follows: Group I (power density 5W; pulse duration 0,01s; irradiation time 3s), Group II (5W; 0,03s, 3s), Group III (8W; 0,01s; 3s) and Group IV (10W; 0,01s; 3s). After results ANOVA and Tukey tests were made. Group IV presented lowering in SBS force (7,33 MPa) when compared with C (10,81MPa). This protocol was founded as a safe and efficient in softening composite layer.
492

Ocorrência de Aggregatibacter actinomycetemcomitans na saliva total em pacientes sob tratamento ortodôntico

Pereira, Lívia de Oliveira 26 June 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-04-15T17:25:19Z No. of bitstreams: 1 liviadeoliveirapereira.pdf: 1685677 bytes, checksum: 07e27133c285258d3d0cd1bb3dd371c4 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-06-02T14:33:39Z (GMT) No. of bitstreams: 1 liviadeoliveirapereira.pdf: 1685677 bytes, checksum: 07e27133c285258d3d0cd1bb3dd371c4 (MD5) / Made available in DSpace on 2016-06-02T14:33:39Z (GMT). No. of bitstreams: 1 liviadeoliveirapereira.pdf: 1685677 bytes, checksum: 07e27133c285258d3d0cd1bb3dd371c4 (MD5) Previous issue date: 2015-06-26 / O tratamento ortodôntico apresenta potencial para causar alterações no periodonto devido ao acúmulo de biofilme, em função da dificuldade de realização de uma adequada higiene bucal na presença de bandas e braquetes. OBJETIVOS: avaliar a ocorrência de Aggregatibacter actinomycetemcomitans na saliva total em indivíduos antes e depois da instalação do aparelho ortodôntico fixo metálico. METODOLOGIA: Foram avaliados 15 pacientes da Clínica de Especialização em Ortodontia da Faculdade de Odontologia – UFJF e de consultórios particulares, do sexo feminino e masculino, com idade média de 18 anos e 3 meses (14-18 anos); 7 homens e 8 mulheres. Amostras de saliva total foram coletadas um mês antes (T1), imediatamente antes (T2), 15 dias antes (T3) e 1 mês após a instalação de aparelho fixo Edgewise Standard (Morelli 10.30.900) nos dentes superiores e inferiores, com exceção dos segundos e terceiros molares. A coleta de saliva foi realizada com o dispositivo Salivete Cortisol (Sarstedt ® Nümbrecht, Alemanha), com swab neutro de poliéster e microtubo. A partir das amostras coletadas, foi realizada a extração do DNA para identificação da bactéria (Aa) por meio do método Reação em Cadeia Polimerase em tempo real. RESULTADOS: Após as análises, não havia a presença da bactéria Aggregatibacter actinomycetemcomitans em nenhum dos intervalos das amostras testadas. Não houve deterioração da condição periodontal (índice de placa visível, profundidade de sondagem e sangramento à sondagem) após T4. CONCLUSÕES: a) não foi possível identificar a ocorrência da bactéria Aggregatibacter actinomycetemcomitans na saliva nem antes (um mês antes), nem no dia da colagem, nem 15 e um mês após a colagem do aparelho fixo; b) o uso do aparelho fixo não contribuiu para o aumento dos índices de placa, profundidade de sondagem e sangramento à sondagem. / Orthodontic treatment has potential to cause changes in periodontal due to biofilm accumulation, due to the difficulty of conducting a proper oral hygiene in the presence of bands and brackets. OBJECTIVES: Evaluate the occurrence of Aggregatibacter actinomycetemcomitans in whole saliva in individuals before and after the installation of metal orthodontic braces and assess whether there has been deterioration of periodontal status (visible plaque index, probing depth and bleeding on probing) after installing braces. METHODS: We evaluated 15 patients of Specialization in Clinical Orthodontics, School of Dentistry - UFJF and private practices, female and male, with an average age of 18 years and 3 months (14-18 years); 7 men and 8 women. Whole saliva samples were collected one month before (T1), immediately before (T2), 15 days before (T3) and one month after the installation of fixed Edgewise Standard unit (Morelli 10.30.900) on the upper and lower teeth, except the second and third molars. The saliva collection was done with the Salivete Cortisol device (Sarstedt ® Nümbrecht, Germany), with neutral swab polyester and micro tube. From samples collected, extraction of DNA for bacteria identification was carried out (Aa) by Polymerase Chain Reaction method in real time. RESULTS: After the analysis, there was no presence of bacteria Aggregatibacter actinomycetemcomitans in any of the intervals of the samples tested. There was no deterioration of the periodontal status (visible plaque index, probing depth and bleeding on probing) after T3. CONCLUSIONS: a) Unable to identify instances of Aa bacteria in saliva either before or after bonding of fixed appliances; b) the use of braces did not contribute to increase plaque index, probing depth and bleeding on probing.
493

Desenvolvimento de um dispositivo posicionador de acessórios ortodônticos com precisão vertical

Mota Júnior, Sergio Luiz 29 March 2016 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-26T14:40:46Z No. of bitstreams: 1 sergioluizmotajunior.pdf: 31675383 bytes, checksum: 4a7f6f6e29158d411892c2d4acac4c92 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-27T11:29:40Z (GMT) No. of bitstreams: 1 sergioluizmotajunior.pdf: 31675383 bytes, checksum: 4a7f6f6e29158d411892c2d4acac4c92 (MD5) / Made available in DSpace on 2016-07-27T11:29:40Z (GMT). No. of bitstreams: 1 sergioluizmotajunior.pdf: 31675383 bytes, checksum: 4a7f6f6e29158d411892c2d4acac4c92 (MD5) Previous issue date: 2016-03-29 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / O correto posicionamento dos bráquetes é importante para garantir o alinhamento e nivelamento dos dentes durante o tratamento ortodôntico. Há instrumentos posicionadores que são utilizados para determinar a posição vertical adequada dos acessórios na superfície dentária. Mesmo estes instrumentos são passíveis de erros durante sua utilização, por permitirem a inclinação vestíbulo-lingual, levando os bráquetes a uma posição inadequada. Prejudicam todo o tratamento, e causam problemas dentários individuais como: alteração do comprimento do arco dentário; provocam intrusões, extrusões, contatos pré-maturos e; consequentemente comprometem todo o sistema mastigatório. Baseado nesta limitação dos instrumentos posicionadores verticais atualmente disponíveis no mercado, o objetivo deste estudo foi descrever o desenvolvimento, apresentar e testar um posicionador do tipo estrela que impeça a inclinação vestíbulo-lingual durante o seu uso. O instrumento foi criado, modelado, patenteado e prototipado para os testes laboratoriais. Para os testes, foram formados quatro grupos com diferentes tempos de experiência clínica em Ortodontia, composto por seis participantes em cada grupo. Cada indivíduo colou bráquetes edgewise 0,022”x0,028” em um manequim typodont com maloclusão Classe I em incisivos, caninos e pré-molares superiores e inferiores. Eles utilizaram primeiramente a estrela de Boone e posteriormente a Estrela UFJF (houve pelo menos 30 dias de diferença entre as colagens). Os estudos mostraram que o uso da Estrela UFJF propiciou médias de colagem mais próximas à considerada ideal no presente estudo (4mm) nos grupos que apresentavam alguma experiência em Ortodontia. Nos grupos de dentes avaliados, o desvio padrão em relação 4mm foi menor quando utilizada a Estrela UFJF se comparado ao uso da estrela de Boone. Todos experimentos apresentaram menores variâncias quando utilizada a Estrela UFJF. Conclui-se, desta forma, que o instrumento desenvolvido apresentou menores variações no posicionamento vertical dos bráquetes ortodônticos quando associado à experiência clínica, sendo esta necessária para seu uso. / The bracket placement is important for the appropriate teeth alignment and leveling during orthodontic treatment. Instruments can be used to determine the position of vertical attachments at dental surface. They are prone to fail during their use because they allow buccolingual inclination and take wrong position of attachments. It may jeopardize a treatment, causing to individuals severe dental problems, such as change the length of the dental arch, intrusions, extrusions, premature contacts and even commit all estomatognatic system. Based on the vertical limitation of some instruments positioners, the aim of this study was to develop and test a star-like positioner that prevents a buccolingual inclination during its use. The instrument was created, modeled, patented and prototyped for laboratory tests. For analysis, 4 groups were defined with different clinical experience in orthodontics, with 6 participants in each group. Each individual bonded edgewise 0.022x0,028in brackets in a typodont with Class I malocclusion in maxillary and mandibular incisors, canines and premolars, first with a Boone gauge and at least 30-days after, with Estrela UFJF. Studies showed that Estrela UFJF had averages closer to the ideal (4mm) in groups with some experience in orthodontics than Boone gauge. In all groups available, the standard deviation was lower with the Estrela UFJF than with Boone gauge. Specific groups of teeth, which variances were lower with Estrela UFJF than with Boone gauge. It is concluded that the developed instrument presented less variations in bracket vertical positioning and some clinical orthodontic experience is necessary to its use.
494

Biofonctionnalisation du silicium poreux pour la détection de MMP-8 (Collagénase-2) / Functionalization of porous silicon for MMP-8 (Collagénase-2) biosensing

Massif, Laurent 12 January 2012 (has links)
La métalloprotéinase matricielle (MMP)-8 ou collagénase-2 est capable de rompre les molécules natives, triples hélices, du collagène interstitiel, initiant ainsi le remodelage cellulaire lors du déplacement dentaire induit par une force orthodontique. C'est un bio-marqueur incontournable du remaniement tissulaire parodontal. L'augmentation de l'expression et de l'activation de MMP-8 dans le fluide gingival reflète l'activité du remodelage parodontal induit par les forces orthodontiques. En moyenne, la concentration de MMP-8 prélevée dans le fluide gingival des patients orthodontiques est 12 fois plus élevée (56 ± 50 µg/l contre 4,6 ± 4 µg/l) que chez les patients non orthodontiques. Le suivi des fluctuations de MMP-8 durant le déplacement orthodontique nécessite la mise au point d'un biocapteur. L'objectif de ce travail est d'utiliser une structure photonique à base de silicium poreux pour la conception d'un biocapteur optique de la MMP-8. Nous avons déterminé le choix du substrat de silicium poreux (PSi) le plus adapté à notre application avec une surface spécifique élevée et pores suffisamment ouverts pour l'infiltration des biomolécules qui sont des anticorps anti-MMP-8. Ensuite nous avons mis en place un procédé de fonctionnalisation chimique et biologique de la surface interne de ces échantillons. / The matrix métalloprotéinase (MMP) 8 or collagenase 2 is able to cleave native molecules, triple helixes, of the interstitial collagen, so introducing the cellular reshaping during orthodontic tooth movement. It is a major biomarker of the periodontal tissular remodeling. The increase of the expression and the activation of MMP-8 in the gingival fluid reflects the activity of the periodontal remodeling. On average, the concentration of MMP-8 taken in the gingival fluid of the orthodontic patients is 12 times as raised(brought up) (56 ± 50 µg / l against 4,6 ± 4 µg / l) that at the not orthodontic patients. Followed it by fluctuations in MMP-8 during the orthodontic movement require the development of a biosensor. The objective of this work is to use a photonique structure with porous silicon for the conception of an optical biosensor of the MMP-8. We determined the choice of the substratum of porous silicon (PSi) the most adapted to our application with a high specific surface and pores opened enough for the infiltration of the biomolecules which are antibodies anti-MMP-8. Then we set up a process of chemical and biological fonctionnalisation of the internal surface of these samples.
495

Efeitos da movimentação dentária mesiodistal para área de rebordo alveolar atrófico: avaliação por meio de modelos digitais / Mesiodistal dental movement toward atrophic alveolar ridge: digital models assessment

Francyle Simões Herrera Sanches 10 April 2015 (has links)
Objetivos: O objetivo deste estudo foi avaliar em adultos com perdas dos primeiros molares inferiores permanentes, as inclinações e angulações dentárias dos dentes adjacentes, bem como a espessura do rebordo após movimentação mesial de segundos molares para suprir a perda e verticalização dos segundos molares para reabilitação protética. Métodos: Foram selecionados 2 grupos de estudo. O Grupo Fechamento (GF) foi composto por 12 hemiarcos com ausência de primeiros molares permanentes e espaços variando entre 2 a 7mm, que foram tratadas ortodonticamente com fechamento do espaço. O Grupo Abertura (GA) foi composto por 14 hemiarcos com ausência de primeiros molares permanentes e espaços variando entre 7,1 a 12mm, que foram tratadas ortodonticamente com verticalização do segundo e terceiro molar e reabertura de espaço para reabilitação protética. Avaliou-se em modelos dentários digitais a angulação, a inclinação, a dimensão cérvico-oclusal e a espessura do rebordo. As comparações interfases e intergrupos foram realizadas com os testes t-pareado e t-independente respectivamente (p<0,05). Resultados: Houve melhora na angulação dos segundos molares inferiores tanto no GF quanto no GA, mostrando eficácia da mecânica em ambas as terapias; não houve alterações significantes nas inclinações vestibulolinguais dos dentes posteriores em ambos os grupos; a espessura do rebordo aumentou no GF e manteve-se constante no GA. Conclusões: As duas modalidades de tratamento demonstraram resultados adequados. A escolha do plano de tratamento deve ponderar a relação custo-benefício de cada caso, considerando-se a dimensão inicial do espaço, a presença dos terceiros molares, as condições periodontais iniciais, o tempo de tratamento e o custo financeiro. / Objectives: The aim of this study was to evaluate, in adults with loss of the first permanent molars, the inclinations and angles of adjacent teeth as well as the alveolar ridge thickness after mesial movement of second molars to close the space of the tooth loss and second molar uprighting to rehabilitation prosthetic. Methods: Two study groups were selected. The Group Closure (GC) was composed of 12 quadrants with no permanent first molars and edentulous spaces varying from 2 to 7mm, which were treated with orthodontic space closure. The Group Opening (GO) was composed of 14 quadrants with no permanent first molars and edentulous spaces varying from 7.1 to 12mm, which were treated with orthodontic uprighting of the second and third molars and reopening space for prosthetic rehabilitation. In digital dental models were evaluated the angulation, inclination, the cervical-occlusal dimension and alveolar ridge thickness. Interphase and intergroup comparisons were performed with with paired t-test and independent t-test, respectively (p <0.05). Results: There was improvement in the angulation of the mandibular second molars both in GC and GO, showing the mechanical efficiency in both therapies; there were no significant changes in buccolingual inclinations of the posterior teeth in both groups; the alveolar ridge thickness increased in GC and remained constant in GO. Conclusions: Both treatment modalities have demonstrated appropriate results. The choice of treatment plan should consider the cost-benefit of each case, taking into account the initial dimension of the space, the presence of third molars, initial periodontal conditions, treatment time and the financial cost.
496

Presença de nódulo pulpar e reabsorção radicular externa em dentes tratados ortodonticamente

Ana Carolina Iglesias Rosa 27 July 2008 (has links)
O tratamento ortodôntico, mesmo quando corretamente executado, pode causar alterações pulpares na forma de calcificações e reabsorções. O objetivo desse estudo foi avaliar a ocorrência de reabsorção radicular e nódulos pulpares em três diferentes técnicas de movimentação ortodôntica: Técnica de Ricketts (G1 n=23), Straight Wire simplificada (G2 n=21) e Straight Wire prescrita pelo Dr. Leopoldino Capelozza (G3 n=26). Radiografias panorâmicas de setenta pacientes foram avaliadas, antes e após o término do tratamento ortodôntico, com o auxílio de negatoscópio e lupa de 4X. Avaliou-se a presença ou ausência de nódulos e o grau de reabsorção radicular: grau 1 (ausência ou reabsorção mínima); grau 2 (> que 1 mm e a 2 mm); grau 3 (entre 2 mm e 1/3 da raiz) e grau 4 (mais 1/3 da raiz). O resultado com relação ao número de nódulos pulpares foi em ordem decrescente: G1 (4/23) > G3 (3/26) > G2 (1/21), entretanto não houve diferença estatisticamente significante entre os grupos ao nível de 5 %. Quanto às reabsorções, nenhum grupo apresentou grau 4. O grau 3 de reabsorção foi mais freqüente no G3 (3/26), seguido G3 (14/26) > G2 (7/21). Quanto ao Grau 1: G2 (14/21) > G3 (7/26) > G1 (5/23). Houve diferença estatisticamente significante ao nível de 5% quanto ao grau de reabsorções nas interações G1 X G2 e G2 X G3. Concluiu-se que a técnica ortodôntica empregada pode influenciar de forma significativa no aparecimento de nódulos pulpares e reabsorções radiculares. / Orthodontic treatment, even when properly performed, may cause pulp alterations as calcification and resorption. The purpose of this study is to evaluate the presence of root resorption and pulp nodules in three different techniques of orthodontic treatment: Ricketts Technique (group 1-n=23), Plain Straight Wire (group 2-n=21) and Straight Wire (group 3-n=26). Previous Orthopantogram of seventy patients were analyzed and compared with post orthodontic treatment panoramic X-Ray, using a negatoscope and a 4 X magnifying lens. Presence or absence of nodules were observed, as well as the root resorption degree: first degree (minimum or absence of resorption); second degree (> than 1mm and 2mm); third degree (between 2 mm and 1/3 of the root) and fourth degree (more than 1/3 of the root). The results according with the numbers of pulp nodules were, in decreasing order: G1 (4/23) > G3 (3/26) > G2 (1/21), however, there were no statistic difference among the groups in the level of 5%. About resorption, no group had fourth degree of it, the third degree of resorption were the most frequent on G3 (3/26), followed by G1 (2/23). The second degree was, in decreasing order: G1 (16/23) > G3 (14/26) > G2 (7/21). For first degree: G2 (14/21) > G3 (7/26) > G1 (5/23). There were significant statistic difference (p<0,05) about the resorption on interactions G1 x G2 and G2 x G3. The study concluded that different orthodontic techniques may influence significantly on pulp nodules and root resorption developing.
497

The prevalence of occlusal traits in a selected Western Cape population

Kaka, Joolam January 1993 (has links)
Magister Chirurgiae Dentium (MChD) / state funded programmes are essential to provide a treatment for the dentally handicapped. To address this need a study was undertaken under the auspices of the Orthodontic Department of the University of the Western Cape to assess the orthodontic needs of children in the Western Cape. The purpose of this study was to determine the occlusal traits of Indian children in the Western Cape and to compare them with samples internationally. The sample consisted of 355 children, 12-14 years old, from schools administered by the House of Delegates. They were examined and recorded according to the methods set out by Baume et al. (1973), and Angle's Classification (1899) with the Dewey- Anderson (1919 and 1960) and EI-Mangoury and Mustafa (1991) modifications The results of this study showed that bilateral molar relationships were: normal in 72.9%; mesial in 5.8% and distal in 15.5% of the children examined. The remaining had an asymmetrical molar relationship (5.8%). The upper incisal area was found to be the most crowded area in the mouth followed by the lower incisal area. Anterior crowding was present in 58.2% and spacing in 12.7% of the sample. The mean overjet was 2.7mm and the mean overbite 2 .1mm. In the posterior segments, open bites accounted for approximately 6.5% and crossbites for 8.3% On the basis of Angle's Classification it was found that 17.1% had a normal occlusion and 54.9% an Angles Class I malocclusion, 16.9% an Angle's Class II malocclusion and 5.5% an Angle's Class III malocclusion. 5.6% of the candidates had an asymmetrical molar relationship. In comparison to other population groups the results suggest that the incidence of some occlusal traits of this Western Cape sample was similar to that of other population groups while some traits were more prevalent. The pattern of the distribution of Angles Classification was also similar to that reported in studies done elsewhere.
498

Comparing two orthodontic brackets’ bond to fluorosed and non-fluorosed enamel - an in vitro study

Monehi, Serufe Emily January 2014 (has links)
Orthodontic attachments must be able to bond to a wide range of tooth and prosthetic surfaces. Despite the high prevalence of fluorosis in many parts of South Africa (Louw A, Chikte U 1997), only limited information is available on the integrity of the bond between orthodontic brackets and fluorosed teeth. The objective of this study was to measure and compare Shear Bond Strengths (SBSs) of metal and ceramic orthodontic brackets on fluorosed and non-fluorosed teeth. One hundred and twenty (60 fluorosed and 60 non-fluorosed) extracted premolar teeth were divided into four groups A to D, consisting of 30 teeth in each group. BluGloo® was used as an orthodontic adhesive to bond brackets on the buccal surface of each tooth. The experimental groups consisted of Group A, in which Nu-Edge® metal brackets were used and Group B, in which InspireIce® ceramic brackets were bonded to fluorosed teeth. Group C and D consisted of Nu-Edge® metal brackets and InspireIce® ceramic respectively, bonded to non-fluorosed teeth. Bonding techniques were kept the same and standardised for all four groups. An Instron testing device was used to debond and measure the SBSs. SBSs were compared using ANOVA with posthoc analysis done using Dunnett’s C test for pairwise comparisons. Significance was set at P<0.05. The results showed that SBS of Group B>Group C>Group D>Group A. Ceramic brackets bonded to fluorosed teeth had the highest SBS with a mean of 15.78 (SD=9.07) Megapascals (MPa), while metal brackets bonded to fluorosed teeth produced the lowest SBS of 8.41 (SD=4.68) MPa. The SBSs of ceramic brackets bonded to fluorosed teeth was significantly higher than that of SBS of metal brackets bonded to fluorosed teeth, but not significantly different from SBSs obtained from either brackets bonded to non-flurosed teeth. The BluGloo adhesive if used to bond ceramic brackets to fluorosed teeth can produce adequate SBS for clinical use. The recommendation from this study is that ceramic brackets can be used efficiently to bond to fluorosed teeth. A follow up study should be carried out to assess the nature of enamel damage caused during debonding of flourosed teeth. This is a laboratory study and thus the clinical application should be interpreted with caution. / Dissertation (MChD)--University of Pretoria, 2014. / tm2015 / Orthodontics / MChD / Unrestricted
499

Gingivarezessionen und kieferorthopädische Maßnahmen - Eine Literaturübersicht

Kleinmann, Peter 05 October 2015 (has links)
In der Literatur wird die kieferorthopädische Bewegung auch als ätiologischer Faktor für die Entstehung gingivaler Rezessionen gesehen (Dorfman 1978; Toker und Ozdemir 2009). Bereits 1942 beschäftigte sich Oppenheim mit dem Einfluss der Kieferorthopädie auf das parodontale Gewebe und stellte bereits damals fest, dass selbst bei größter Sorgfalt negative Einflüsse auf das Parodont nicht vermieden werden können (Oppenheim 1942). Nach derzeitiger Datenlage scheint folgende Antwort gerechtfertigt zu sein. Im Zuge einer kieferorthopädischen Therapie kann es zu Rezessionen der marginalen Gingiva kommen und dies kann auch teilweise nicht verhindert werden. Die fachlich korrekt durchgeführte kieferorthopädische Therapie scheint per se kein erhöhtes Risiko für die Entstehung von Rezessionen zu sein. Dies setzt eine sorgfältige prätherapeutische Diagnostik, geeignete Kräfte und Verankerungselemente, Beibehaltung einer suffizienten Mundhygiene und die Beachtung anatomischer Limits voraus.:Einleitung 3 Material und Methodik 5 Ergebnis 6 Häufigkeit und Verteilung von Rezessionen 6 Attached Gingiva 8 Biomechanik der kieferorthopädischen Zahnbewegung 11 Plaque, Gingivitis 15 Kraft 20 Intrusion 21 Extrusion 23 Expansion/Dehnung 23 Labial und Lingualbewegung/Labialstand 29 Proklination/Inklination 34 Knochendehiszenz/Knochenbedeckung 43 Systematische Literaturübersicht 59 Vorbeugende Maßnahmen 61 Diskussion 63 Zusammenfassung 68 Literaturverzeichnis 69
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Trends in skeletal maturation patterns in a Western Cape sample

Hansa, Ahmed Ismail January 1987 (has links)
Magister Chirurgiae Dentium - MChD / Skeletal age assessment is not only an important aspect in orthodontic treatment planning, but is also widely used in forensic medicine and physi cal anthropology. Vari aus studi es have shown that chronological age may be at variance with an individual's biologic age. Current research would seem to indicate that the hand-wrist radiograph provides the most accurate method of assessing skeletal age for diagnostic purposes. In recent years the number of patients presenting with malocclusions of a skeletal nature at the University of the Western Cape has increased si gnifi cantly. If it i s accepted that treatment of jaw discrepancies associated with malocclusion is dependent on a large component of dentofacial orthopedics, then by implication it is necessary that a substanti al amount of faci al growth remai ns. The need has therefore arisen for the establishment of skeletal maturation trends in the Western Cape. Skeletal maturity was assessed from hand-wrist radiographs in a sample of 318 Western Cape chi 1dren aged 6 to 16 years for both sexes, utilising the bone specific Tanner-Whitehouse TW-2 scoring system. Data obtai ned from the present study showed a marked di fference in skel etal maturati on trends between femal es of the Western Cape to that of the British norm, while the males showed less divergence. Further, these findings show that in both sexes the epiphyseal bones matured in advance of the TW-standard. Carpal maturation, however, was delayed in the male when compared to the British standard, while that of the female conformed to that of the British standard.

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