Thesis (doctoral)--Universität München, 1934. / At head of title: Aus der Abteilung für Zahn- und Kieferersatz ... des Zahnärtzlichen Instituts der Universität München. "Lebenslauf": p. 5. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains vi, 108 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 52-61).

Thesis (M.S.)--University of Florida, 2004. / Typescript. Title from title page of source document. Document formatted into pages; contains 35 pages. Includes Vita. Includes bibliographical references.

Introduction Dental caries is the most common chronic infectious disease and is associated with plaque, bacteria, diet and saliva. Previous caries experience predicts 1/3 of future caries development. However, there is a lack of knowledge regarding the natural history of caries development at different surfaces and their relative ability to predict caries progression.   Aim The aim of this study was to describe the caries experience and progression of caries at different tooth surfaces during 5 years in patients undergoing orthodontic multibracket treatment. Methods In the previously conducted 452-study, children were examined at 12 and 17 years of age. There were 66 patients with multibrackets at the follow-up who we analyzed. Degrees of caries, fillings and missing tooth were registered in an excel file according to the dental statuses (baseline and follow up).  Excel and SPSS were used to compare the files and create figures.  Results The most affected pair of surfaces at 12 years of age are 36/46 buccally, then occlusally and at 17 years of age 36/46 occlusally and then approximally. The progression of caries and fillings during five years mostly affects 37/47 occlusally and then 17/27 occlusally. A progression also occurred at buccal surfaces 13-23. Conclusion  The results show that occlusal and approximal surfaces at molars experience caries most frequently and the progression is highest for the second molars. There was also a progression of caries noted on 13-23 which could be associated with the multibrackets. This information may be important in future risk assessment models.

Indiana University-Purdue University Indianapolis (IUPUI) / Understanding the factors that increase patients susceptibility to orthodontically induced root resorption is of the utmost importance to the practicing clinician. Numerous studies have been conducted that investigated contributing and etiological factors that tend to increase the amount of external apical root resorption a patient may incur during orthodontic treatment. However, there has been little research that has attempted to determine if patients treated with different slot size orthodontic brackets exhibit the same amount of external apical root resorption. The purpose of this research was to determine if patients treated with the 0.018 x 0.025 slot size bracket and patients treated with the 0.022 x 0.028 exhibited similar amounts of external apical root resorption during orthodontic treatment. Pre and Post treatment panoramic films from 91 consecutively treated orthodontic patients from a private orthodontic practice were used for this study. Each case that was included in the study had been treated with standard edgewise brackets using the Tweed-Merrifield philosophy of treatment. Forty-three cases from the 0.018 group and 48 from the 0.022 group were obtained. Each film that was analyzed was blinded prior to measuring to minimize observer bias. Mitutoyo Digimatic® calipers accurate to the nearest tenth of a millimeter were used for obtaining tooth measurements. Measurements were made from the Cemento-enamel junction and from incisal/occlusal to most apical portion of each incisor and all first molars. Statistical analysis was performed and the results showed no significant correlation between the size of the bracket and the amount of root resorption. No significant correlations existed between the groups for patient age, time in treatment, gender, and angle classification. Statistically significant differences were noted for cases in which extraction of four bicuspids was performed. Subjects belonging to the extraction group demonstrated significantly more external apical root resorption than those in which extractions were not done. This study demonstrated that the incidence of EARR that a patient may incur during treatment is independent of the size of the slot of the orthodontic bracket.

No description available.

published_or_final_version / Dentistry / Master / Master of Dental Surgery

published_or_final_version / Dentistry / Master / Master of Dental Surgery

Thesis (M.Sc.D.)--Boston University School of Graduate Dentistry, 1973. Orthodontics. / Bibliography included.

Orientador: João Roberto Gonçalves / Banca: Cyneu Aguiar Pansani / Banca: Arno Locks / Resumo: A possibilidade de usar fios superelásticos retangulares com níveis de força mais leves (biológicos) permitiria simultâneo alinhamento, nivelamento e torque, o que resultaria em um menor número de fios utilizados, reduzindo custos e tempo de tratamento. Existe uma tendência, principalmente na ortodontia lingual, de se dobrar fios superelásticos (manualmente ou com tratamento térmico/elétrico) para adequar o fio à forma do arco. O objetivo deste trabalho foi avaliar as propriedades mecânicas de fios de NiTi de quatro marcas comerciais diferentes (0,017" x 0,025") após dobras e tratamento elétrico. Os fios foram dobrados com alicates elétricos (sistema DERHT) e com alicate 139 e depois foram comparados com fios retos sem nenhum tratamento (grupo controle) e fios retos com tratamento elétrico sem dobras (grupo controle tratamento elétrico). Na tentativa de simular uma situação clínica, todos os fios foram testados a 36oC na máquina de testes FSI (Sistema Identificador de Forças). Foram testados usando-se braquetes autoligáveis tipo Damon, simulando ativações em segunda ordem de 0 mm a 2 mm. Foram analisadas as seguintes variáveis: força e deslocamento no ponto do limite elástico, força máxima, energia total, energia dissipada, energia perdida, força e deslocamento no início e no fim do platô, inclinação e comprimento do platô. As diferenças estatísticas para os diferentes fios, nos diferentes testes, foram avaliadas pela ANOVA. Os resultados mostraram que: (1) o tratamento elétrico afetou as propriedades mecânicas de todos os fios de maneira geral, existindo uma tendência de diminuição nos níveis de força; (2) quando os fios receberam dobras, todos perderam os platôs de superelasticidade; (3) se o uso de forças leves e constantes é desejável no tratamento ortodôntico, os fios termodinâmicos deveriam ser recomendados na seguinte ordem: Copper NiTi 400, Neo Sentalloy 100 e Copper NiTi 270. / Abstract: The possibility of using superelastic rectangular Nickel-Titanium wires in early stages of treatment with light forces, could allow more three-dimensional control, a small number of wires, lowering costs and treatment time. There is a tendency, especially in lingual orthodontics of bending superelastic wires (manually or with heat treatment) to adequate the wire in the arch anatomy. The aim of this study was to evaluate the mechanical properties of four commercially available 0.017 x 0.025 inch NiTi archwires after bending and heat treatment. The wires were bent with electrical pliers (DERHT System) and with standard bird beak plier and then compared with straight wires as a control group and another electrical treatment control group. All the wires were tested at 360 C in an orthodontic wire-testing device, a so called Force System Identification (FSI) apparatus. In the FSI a two-bracket system using self ligating Damon brackets simulated second order displacements up to 2 mm. The following variables from the activation/deactivation curves were calculated: force and displacement at yield point, maximum force level, total energy up to maximum displacement, energy loss after deactivation, force and displacement at the beginning and at finish of the plateau, and the slope and length of the plateau. Any statistically significant differences in these variables for the different brands and tests were analyzed using one-way analysis of variance. The results showed that: (1) the electrical treatment affected the characteristics of all the wires tested in a different way but with a tendency of lowering the force levels. (2) When the wires were bent they all lost activation and deactivation plateau of superelasticity. (3) If the use of low and constant force levels are desirable in orthodontic treatment, the thermodynamic wires should be recommended in the following order: Copper Niti 400 , NeoSentalloy 100 and Copper Niti 270. / Mestre