Thesis (M.S.)--University of Michigan, 1942.

Thesis (M.S.)--West Virginia University, 2000. / Title from document title page. Document formatted into pages; contains viii, 94 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 46-49).

Aim: To compare the 0.018-inch and 0.022-inch conventional pre-adjusted orthodontic bracket slot systems in terms of the effectiveness of levelling and alignment stage of orthodontic treatment. Design: Prospective, multi-centre randomised clinical trial. Setting: This was undertaken in the secondary care hospital environment in Tayside NHS in the United Kingdom. Subjects and methods: One hundred and five orthodontic patients were randomly allocated to treatment with either the 0.018-inch bracket slot (n= 52) and 0.022-inch bracket slot (n=53) Victory conventional pre-adjusted bracket systems (3M Unitek). The patients were treated in three centres in secondary care hospitals Tayside NHS, United Kingdom. The levelling and alignment stage of treatment was assessed from the start of treatment until the ligation of the working archwire for each bracket slot system (0.016x0.022 stainless steel for the 0.018-inch group and 0.019x0.025 stainless steel for the 0.022-inch group). Periapical radiographs were taken before the start of treatment and after 9 months in treatment for the maxillary central incisors to assess orthodontically-induced inflammatory root resorption (OIIRR). The “Smiles better” questionnaire was completed by the participants at 6 months from the start of treatment. Primary outcome measures: The duration of the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches. Secondary outcome measures: The number of scheduled appointments for the levelling and alignment stage of orthodontic treatment in the maxillary and mandibular arches, OIIRR at 9 months from the start of treatment using periapical radiographs and patient perception of wearing orthodontic appliances. Results: The data from 92 patients (mean age 19.55 years) were analysed after the completion of their levelling and alignment stage of orthodontic treatment. An ANOVA test showed no statistically significant difference in the duration or number of scheduled appointments for the levelling and alignment stage in the maxillary and mandibular arches between the two appliance groups. Non-parametric statistical test showed no statistically significant difference in the severity of OIIRR and patient perception of wearing orthodontic appliances between the two study groups except for the soreness of teeth, where more patients in the 0.022-inch group experienced significant teeth soreness than the 0.018-inch group. Multiple regression analysis determined that 49.6% of the variance in the duration of levelling and alignment duration for the maxillary arch can be explained by five factors: alignment of ectopic tooth, scheduled appointment intervals, gender, bracket slot size system and the number of failed scheduled visits. For the mandibular arch, 50.8% of the variance in the levelling and duration of alignment can be explained by three factors: scheduled appointment intervals, arch irregularity and the number of debonded brackets. Conclusions: There is no difference in the effectiveness of the levelling and alignment stage of orthodontic treatment between the 0.018-inch or 0.022-inch conventional bracket slot systems except for the soreness of teeth.

published_or_final_version / Children's Dentistry and Orthodontics / Doctoral / Doctor of Philosophy

Objective: The purpose of this study was to determine the fluoride recharging capability of Opal Seal, a fluoride releasing orthodontic primer, as compared to Transbond XT, the control. Material and Methods: 1mm x 5mm disks of Opal Seal and Transbond were prepared according to the respective manufacturer’s instructions. Initially, the samples were stored in deionized water (DI) for 8 weeks. The samples were then randomly divided into one of two groups: Over-the-counter (OTC) fluoride mouthwash and prescription strength (PS) fluoride mouthwash. The OTC group samples were immersed in 5mL of 0.0219% sodium fluoride containing mouthwash for one minute every day for seven days. The PS group samples were immersed in 5mL of 0.2% sodium fluoride containing mouthwash for one minute. All of the samples were suspended in 5mL fresh DI water and fluoride release measurements were taken at baseline (the end of initial 8 weeks of storage), 24 hours, 3 days, 5 days, 7 days, and 14 days. Results: Opal Seal samples treated with the OTC fluoride mouthwash exhibited significant fluctuation in fluoride ion release across time (p=0.0058). However, there were no statistically significant differences in fluoride ion release between the individual timepoints and baseline. Similarly, Opal Seal samples treated with the PS fluoride mouthwash exhibited significant variation in the fluoride ion concentration across time (p< 0.001), and a statistically significant increase over baseline was seen at 24 hours only (p= 0.0006). The control group samples treated either with the OTC or PS mouthwash did not exhibit any significant difference in fluoride ion release between any individual timepoint and baseline. Conclusion: For Opal Seal and Transbond XT, there were no statistically significant differences of fluoride concentration at any timepoint compared to baseline measurements when using OTC mouthwash. When using PS mouthwash, there was a small, statistically significant increase of fluoride concentration of the Opal Seal samples after 24 hours but no differences were seen at any other timepoints. Opal Seal did not demonstrate a substantial amount of fluoride recharge when fluoride mouthwash is used as a fluoride delivery vehicle. Future well-designed randomized controlled trials are needed to evaluate the efficacy of Opal Seal primer when coupled with the use of fluoride mouthwashes.

Friction, binding and notching are the factors that contribute to resistance to sliding during orthodontic tooth movement. However, most attempts at reducing resistance aim only to reduce the archwire/ligature friction. In this study, a novel bracket with a unique design aimed to reduce all three components of resistance to sliding. Four types of brackets (passive and active self-ligating, traditionally ligated and the novel bracket, (n=5, each) were tested at 0, 2, 4, 6, and 8ᵒ of tip on a 0.019 x 0.025”archwire. The resistance to sliding values were recorded. At 0ᵒ, the passive self-ligating and novel bracket showed reduced resistance when compared to the traditionally ligated bracket (P< 0.05). At the other angles of tip, no differences were observed among the brackets. These data suggest that the novel bracket could potentially decrease the resistance to sliding during orthodontic treatment and further studies are indicated to test the improved bracket design.

ABSTRACT This research report quantifies the soft tissue profile changes that occur as a result of the placement of orthodontic brackets. It also assesses whether patients are able to perceive any changes in their own profiles immediately post bonding. Using a standardised photographic technique, profile photographs were taken of a group of patients both before and immediately after the placement of orthodontic brackets. A series of angular and linear measurements were made each on the photographic images using a computer software program. The data obtained from the ‘before’ and ‘after’ photographs were then compared. Patients were also asked several standard questions about their ‘before’ and ‘after’ photographs. The results indicate that the placement of orthodontic brackets can cause changes in the soft tissue profile of patients. Statistically significant changes were found for four of the ten profile measurements that were investigated, namely the Nasolabial Angle, the Maxillo-Mandibular Contour, the Interlabial Angle and the Lower Lip Projection. It was also found that patients are able to perceive changes in their profiles brought about by the placement of orthodontic brackets, and that most are able to correctly recognise which photograph was taken after bracket placement. The majority of patients prefer the photographs of their profiles taken before bracket placement. This study was conducted using a standardised orthodontic bracket. Future research may be carried out to compare profile changes occurring with other bracket systems. This may assist manufacturers in designing brackets that are more comfortable and acceptable for patients.

O objetivo deste trabalho foi estudar os efeitos dos lacebacks ativos e passivos na biomecânica da fase de nivelamento, utilizando-se a técnica MBT. A amostra foi constituída de 29 sujeitos de pesquisa (22 do gênero feminino e 7 do gênero masculino), brasileiros, leucodermas e pardos, portadores de má oclusão de Classe I e com idade média de 15 anos e 5 meses. O tratamento ortodôntico foi planejado com as extrações dos primeiros pré-molares e, durante a fase estudada, foram empregados apenas fios de aço inoxidável (0.014", 0.016", 0.018", 0.020" e 0.019" x 0.025"). Os recursos de ancoragem utilizados para os arcos dentários superior e inferior foram, respectivamente, o aparelho extrabucal tipo IHG e o arco lingual fixo. De acordo com a indicação dos lacebacks, a amostra foi dividida em quatro grupos: grupo I – 14 sujeitos que utilizaram lacebacks ativos no arco dentário superior; grupo II – 9 sujeitos que utilizaram lacebacks passivos no arco dentário superior; grupo III – 19 sujeitos que utilizaram lacebacks ativos no arco dentário inferior e grupo IV – 10 sujeitos que utilizaram lacebacks passivos no arco dentário inferior. Para cada indivíduo da amostra foram tomadas duas telerradiografias laterais, uma ao início e outra ao término da fase de nivelamento, com um intervalo médio de 21 meses. Os dados foram coletados utilizando-se o método cefalométrico computadorizado. Para a análise de erros, o método cefalométrico foi repetido em todos os sujeitos da amostra, pelo mesmo operador, com um intervalo mínimo de 15 dias entre as medidas. Os resultados indicaram que as variações observadas foram compatíveis com as estimativas de erros operacionais em estudos cefalométricos. Após a análise estatística e a interpretação dos resultados, verificou-se que, no grupo I, apenas a coroa do primeiro molar superior sofreu um movimento mesial e que tanto a coroa como a raiz do incisivo central superior apresentaram um movimento em direção lingual. No entanto, as inclinações destes dentes não foram alteradas. No grupo II, o primeiro molar superior se manteve estável e somente a coroa do incisivo central superior se movimentou em direção lingual, produzindo uma rotação horária deste dente. No grupo III, observou-se uma mesialização, tanto da coroa como da raiz, e extrusão do primeiro molar inferior, enquanto a posição do incisivo central inferior permaneceu inalterada. As inclinações destes dentes também não foram alteradas. No grupo IV, verificou-se que nem o primeiro molar inferior nem o incisivo central inferior apresentaram variações no sentido ântero-posterior. Verticalmente, houve extrusão apenas do primeiro molar inferior. / The purpose of this study was to evaluate the effects of active and passive lacebacks in the biomechanics of the leveling phase, using the MBT technique. The sample was composed of 29 Brazilian subjects (22 female and 7 male), Caucasian, with Class I malocclusion and mean age of 15 years and 5 months. The orthodontic treatment was planned with the extraction of the first premolars, and the leveling phase was performed with stainless steel wire only (0.014", 0.016", 0.018", 0.020" e 0.019" x 0.025"). The anchorage control devices used in the upper and lower arches were, respectively, the IHG extraoral appliance and the fixed lingual arch. According to the type of laceback prescription, the sample was divided into four groups: group I – 14 subjects in which active lacebacks were used in the upper arch; group II – 9 subjects in which passive lacebacks were used in the upper arch; group III – 19 subjects in which active lacebacks were used in the lower arch; group IV – 10 subjects in which passive lacebacks were used in the lower arch. For each subject of the sample two lateral cephalometric radiographs were taken: one at the beginning and another at the end of the leveling phase, with a mean interval of 21 months. The data were collected using the resources of computerized cephalometry. To perform the analysis of errors, the cephalometric method was repeated in all subjects of the sample, by the same operator, with a minimum interval of 15 days between the measurements. The results revealed that the observed variations were compatible with the estimates of operational errors in cephalometric studies. After statistical analysis and interpretation of the results, it was observed that in group I, only the crown of the upper first molar presented a mesial movement. As to the upper central incisor, both the crown and the root presented a lingual movement. However, the inclination of these teeth was not affected. In group II, the upper first molar remained stable and only the crown of the upper central incisor moved lingually, leading to a clockwise rotation of this tooth. In group III, a mesial movement of both the crown and the root of the lower first molar was observed, along with its extrusion, whereas the position of the lower central incisor remained unchanged. The inclination of these teeth was not affected either. In group IV, it was observed that neither the lower first molar nor the lower central incisor experienced variations in the anteroposterior sense. Vertically, there only was extrusion of the lower first molar.

O objetivo deste trabalho foi avaliar a quantidade de resina residual após a descolagem de braquetes e a perda e/ou desgaste de esmalte ocorrido durante as fases de: colagem, descolagem e remoção dos remanescentes resinosos, na área do braquete e adjacente. A amostra foi constituída de 150 pré-molares, dividida em dois grupos de acordo com o tipo de material do braquete utilizado: metálico (n=75) e cerâmico (n=75), nas duas primeiras fases do estudo, colagem e descolagem. Os procedimentos de colagem foram realizados de acordo com a International Organization for Standardization (2003), e a descolagem segundo a orientação preconizada pelo fabricante. Na fase de remoção dos remanescentes resinosos foram considerados cinco grupos de acordo com o protocolo de acabamento/polimento e prescrição dos respectivos fabricantes: FF diamantada + Soflex; Pedra Shofu; Dentaurum Carbide; Komet Carbide e Jet Carbide, com auxilio de lupas telescópicas sob a magnificação 3x. A avaliação qualitativa (ARIm e ESI) foi realizada por meio de fotografias digitais (lupa estereoscópica - Olympus SZ61). A avalição quantitativa foi realizada pelo método de medição por Coordenada - Coordinate Measuring Machines (Mitutoyo), mod. Legex CNC 9106 - Perfil de linha. As possíveis diferenças entre os protocolos de acabamento/polimento foram avaliadas pela análise de variância (ANOVA) e pelo teste de comparações múltiplas de Tukey. As quantidades médias de resina residual encontrada na área sob a base do braquete, após acabamento/polimento foram: Diamantada FF + Soflex (10,4 m ±10,5), Pedra Shofu (18,5 m ± 12,1), Dentaurum Carbide (11,2 m ± 11,9), Komet Carbide (9,5 m ± 10,8) e Jet Carbide (22,8 m ± 24,0). E na área adjacente: Diamantada FF + Soflex (14,9 m ± 13,0), Pedra Shofu (22,8 m ±19,5), Dentaurum Carbide (21,4 m ±18,5), Komet Carbide (9,6 m ± 7,7), Jet Carbide (27,8 m ± 24,5). Desta forma, constatou-se que, em geral, os protocolos de acabamento/polimento deixaram maior quantidade de resina residual sobre a área adjacente que na área do braquete, com exceção do protocolo Komet Carbide, que teve desempenho semelhante em ambas as áreas. E as quantidades médias de perda e/ou desgaste do esmalte na área do braquete foram: Diamantada FF + Soflex (-134,9 m ± 56,4), Pedra Shofu ( 39,2 m ± 12,8), Dentaurum Carbide ( 70,5 m ± 27,9), Komet Carbide (-44,8 m ± 14,3) e Jet Carbide ( 68,2 m ± 35,7) na área do braquete, enquanto na área adjacente: Diamantada FF + Soflex (-124,7 m ± 133,1), Pedra Shofu (- 37,9 m ± 25,1), Dentaurum Carbide (- 60,1 m ±32,4), Komet Carbide (-36,6 m ± 19,5) e (Jet Carbide 65,4 m ± 65,0) (Tabela 5.9). Ressalta-se que em ambas as áreas de avaliação, o protocolo (Diamantada FF + Soflex) foi responsável pela maior quantidade de perda e/ou desgaste, diferenciando-se com significância estatística dos demais protocolos. Com base nestes resultados podemos concluir que os protocolos de acabamento/polimento avaliados demonstraram excelente desempenho na remoção dos remanescentes resinosos embora nenhum deles tenha sido capaz de remover totalmente o material de colagem, todos danificaram o esmalte, sendo o protocolo Komet carbide o mais diferenciado. / The objective of this study was to evaluate the quantity of residual resin after removal of brackets and the loss and//or wear-and-tear of enamel occurring during the phases of fixing, detaching and removal of remnant resin in the bracket area and its adjacent. The sample was made up of 150 premolars, divided into two groups in accordance with the type of bracket material used: metal (n=75) and ceramic (n=75), in the two initial phases of study, fixing and removal. Fixing procedures were carried out in accordance with the International Organization for Standardization, (2003), and removal according to orientation advocated by the manufacturer. In the removal of remnant resin phase five groups were considered, all in agreement with the finishing/polishing protocol and prescription of the respective manufacturers: FF diamantada + Soflex; Pedra Shofu; Dentaurum Carbide; Komet Carbide and Jet Carbide, and with the aid of telescopic magnifying glass of three-fold magnification Qualitative evaluation (ARIm and ESI) was done by means of digital photographs(stereoscopic magnifying glass Olympus SZ61). Quantitative evaluation was conducted using the coordinate medication method - Coordinate Measuring Machines (Mitutoyo), mod. Legex CNC 9106 - line profile. Possible differences between finishing/polishing protocols were evaluated via variance analysis (ANOVA), and by Tukey Multiple Comparison test. Median quantities of residual resin found in the region below the base of the bracket, following finishing/polishing were: Diamantada FF + Soflex (10,4 m ±10,5), Pedra Shofu (18,5m ± 12,1), Dentaurum Carbide (11,2 m ± 11,9), Komet Carbide (9,5 m ± 10,8) and Jet Carbide (22,8 m ± 24,0). In this way, it was confirmed that finishing/polishing protocols, in general, left the major part of residual resin below the adjacent area than in the bracket area, with the exception of Komet Carbide protocol, displaying similar performance in both areas Median quantities of loss and/or wearand- tear of enamel in the bracket area were: Diamantada FF + Soflex (-134,9 m ± 56,4), Pedra Shofu ( 39,2 m ± 12,8), Dentaurum Carbide ( 70,5 m ± 27,9), Komet Carbide (-44,8 m ± 14,3) and Jet Carbide ( 68,2 m ± 35,7) in bracket area, while in adjacent area: Diamantada FF + Soflex (-124,7 m ± 133,1), Pedra Shofu (- 37,9 m ± 25,1), Dentaurum Carbide (- 60,1 m ±32,4), Komet Carbide (-36,6 m ± 19,5) and (Jet Carbide 65,4 m ± 65,0) (Table 5.9) Standing out in both areas of evaluation, protocol (Diamantada FF + Soflex) was responsible for the major quantity of loss and /or wear and tear, differentiating itself from the other protocols by significant statistics. Based on these results, we can conclude that the finishing/polishing protocols evaluated, displayed excellent performance in the removal of remnant resin, although none have totally been capable of removing fixing material, and all damaged the enamel, with Komet protocol being the most differentiated.

Magister Chirurgiae Dentium - MChD / To compare the efficacy of two fluoride containing materials, namely, FluorSure and Duraphat, in protecting the enamel around and underneath the orthodontic brackets against decalcification. / South Africa