Avaliação do sistema de força e estabilidade a longo prazo gerado por molas T do grupo B
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Data
2010-08-20
Autores
Caldas, Sergei Godeiro Fernandes Rabelo [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Comparar o efeito do tipo de pré-ativação (curvatura ou dobra) e avaliar o efeito do alívio de tensão estrutural sobre a estabilidade do sistema de força gerado por molas “T” do grupo B confeccionadas com fio de beta-titânio 0,017” x 0,025” (TMA®, Ormco Corporation, Glendora, EUA). Materiais e Métodos: Dois artigos científicos foram redigidos e utilizados para a avaliação dos propósitos apresentados. Resultados: As molas “T” pré-ativadas por curvatura produziram forças horizontais significativamente menores (variando de 51 gf a 405 gf) do que as molas pré-ativadas por dobras (variando de 106 gf a 431 gf). Não foram encontradas diferenças em relação aos momentos produzidos durante a desativação em ambos os grupos. As proporções momento-força foram sistematicamente maiores nas molas “T” pré-ativadas por curvatura do que as molas pré-ativadas por dobras (de 5,7 mm a 41,1 mm versus 5,4 mm a 15,2 mm), exceto para 5 mm de ativação. Foram encontradas diferenças significativas nas relações carga-deflexão (grupo curvatura = 78,07 gf/mm e grupo dobra = 71,65 gf/mm) e na posição neutra (grupo curvatura = - 0,18 mm e grupo dobra = -0,99 mm). As forças horizontais foram maiores (P<0,001) para o grupo imediato (267,6 gf) comparado aos demais grupos (200,7 gf a 181,7 gf), os quais não foram diferentes entre si. A posição neutra foi maior no grupo imediato (-0,99 mm) do que nos demais grupos (P<0,001) e o tempo não teve influência sobre a relação carga-deflexão (P=0,129). Os momentos gerados na desativação foram geralmente maiores (P=0,001) no grupo imediato (1932,6 gf.mm) do que nos demais grupos (1696,6 gf.mm a 1471,3 gf.mm), os quais não foram diferentes entre si. Todos os grupos produziram proporção momento-força semelhantes (P=0,640). Conclusões: As molas “T” pré-ativadas por curvatura apresentaram forças horizontais menores...
Compare the effect of preactivation (curvature or concentrated bend) and evaluate the changes in force system caused by stress relaxation of group B T-loop springs made with .017” x .025” beta-titanium (TMA®, Ormco Corporation, Glendora, USA) wires. Materials and Methods: Two research papers were written and analyzed for the evaluation of the aims presented. Results: TLSs preactivated by curvature delivered horizontal forces significantly lower (ranging from 51 gf to 405 gf) than the TLS preactivated by concentrated bends (ranging from 106 gf to 431 gf). No differences were found in relation to the moments produced throughout the deactivation of both groups. The moment-to-force ratios were systematically higher on the TLSs preactivated by curvature than the TLS preactivated by concentrated bends (from 5.7 mm to 41.1 mm versus 5.4 mm to 15.2 mm), except on 5 mm of activation. Significant differences were found in the load-deflection rates (curvature group = 78.07 gf/mm and concentrated bends group = 71.65 gf/mm) and neutral position (curvature group = -0.18 mm and concentrated bends group = -0.99 mm). The horizontal forces were higher (P<.001) for immediate group (267.6 gf) compared to the other 8 groups (200.7 gf to 181 gf) which were not different among themselves. The neutral position was greater in immediate group (-0.99 mm) than on the other groups (P<.001), and time did not have an effect on the load-deflection ratio (P=.129). The moment levels produced throughout the deactivation were generally higher (P=.001) for immediate group than for the other groups (1696.6 gf.mm to 1471.3 gf.mm) which were not different among themselves. All groups produced similar moment-to-force ratios (P=.640). Conclusions: The TLSs preactivated by curvature delivers lower horizontal forces and higher MF and LD ratios than the TLS preactivated by concentrated bends... (Complete abstract click electronic access below)
Compare the effect of preactivation (curvature or concentrated bend) and evaluate the changes in force system caused by stress relaxation of group B T-loop springs made with .017” x .025” beta-titanium (TMA®, Ormco Corporation, Glendora, USA) wires. Materials and Methods: Two research papers were written and analyzed for the evaluation of the aims presented. Results: TLSs preactivated by curvature delivered horizontal forces significantly lower (ranging from 51 gf to 405 gf) than the TLS preactivated by concentrated bends (ranging from 106 gf to 431 gf). No differences were found in relation to the moments produced throughout the deactivation of both groups. The moment-to-force ratios were systematically higher on the TLSs preactivated by curvature than the TLS preactivated by concentrated bends (from 5.7 mm to 41.1 mm versus 5.4 mm to 15.2 mm), except on 5 mm of activation. Significant differences were found in the load-deflection rates (curvature group = 78.07 gf/mm and concentrated bends group = 71.65 gf/mm) and neutral position (curvature group = -0.18 mm and concentrated bends group = -0.99 mm). The horizontal forces were higher (P<.001) for immediate group (267.6 gf) compared to the other 8 groups (200.7 gf to 181 gf) which were not different among themselves. The neutral position was greater in immediate group (-0.99 mm) than on the other groups (P<.001), and time did not have an effect on the load-deflection ratio (P=.129). The moment levels produced throughout the deactivation were generally higher (P=.001) for immediate group than for the other groups (1696.6 gf.mm to 1471.3 gf.mm) which were not different among themselves. All groups produced similar moment-to-force ratios (P=.640). Conclusions: The TLSs preactivated by curvature delivers lower horizontal forces and higher MF and LD ratios than the TLS preactivated by concentrated bends... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Ortodontia, Biomecânica, Movimentação dentária, Orthodontics, Biomechanics, Tooth movement
Como citar
CALDAS, Sergei Godeiro Fernandes Rabelo. Avaliação do sistema de força e estabilidade a longo prazo gerado por molas T do grupo B. 2010. 123 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Odontologia de Araraquara, 2010.