Avaliação in vitro da resistência adesiva de braquetes ortodônticos variando-se o tempo de armazenamento e o tipo de fotoativação: luz halógena e led
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Data
2007-10-31
Autores
Di Nicoló, Rebeca [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo in vitro foi comparar os efeitos da fotoativação pelos sistemas luz halógena e LED na adesão de braquetes ortodônticos em diferentes tempos pós-colagem (imediato, 24h e 7d). Braquetes com adesivo pré-aplicado (Gemini series; APC adhesive precoated brackets; 3M Unitek, USA) foram colados na superfície vestibular de dentes bovinos. O esmalte dos dentes foi condicionado utilizando-se o primer auto-condicionante (Transbond SEP, 3M Unitek, USA) em todos os espécimes, conforme recomendações do fabricante. Setenta e dois dentes foram divididos em 2 grupos (n=36), conforme o sistema de fotoativação (luz halógena ou LED) e sub-divididos (n=12) de acordo com o tempo pós-colagem. Para os grupos luz halógena, o tempo de fotoativação foi de 20s e para os grupos LED foi de 10s. O teste de resistência ao cisalhamento foi realizado com auxílio de uma máquina de ensaios universal nos diferentes tempos pós-colagem: imediato, 24h e 7d. O valor médio de adesão para os grupos luz halógena foi de 20,01±5,24MPa e, para os grupos fotoativados pelo sistema LED 17,35±5,07MPa, sendo estes resultados estatisticamente diferentes. Quando comparado o efeito do tempo pós-colagem, os resultados revelaram que os valores de adesão foram significantemente maiores para o tempo de 7d. O resultado do teste ANOVA 2 – fatores revelou não existir diferença estatística entre a interação sistema de fotoativação e tempos pós-colagem. O teste de Tukey mostrou que para as 4 condições experimentais nos tempos imediato e 24h, os resultados não diferiram estatisticamente, independentemente do sistema de fotoativação. Somente com relação ao grupo luz halógena-7d, os resultados mostraram diferenças estatisticamente significantes. O grupo LED-7d desempenhou comportamento intermediário entre os grupos. O índice de adesivo remanescente não revelou diferenças... (Resumo completo, clicar acesso eletrônico abaixo)
The objective of this in vitro study was to compare the effects of polymerization using halogen and LED system on shear bond strengths (SBS) at different debond times of immediately, 24 hours and 7 days after bonding. Pre-coated brackets (Gemini series; 3M Unitek, USA) were bonded to bovine incisors in all specimens. Teeth were conditioned with a self-etching primer (Transbond SEP, 3M Unitek, USA) as recommended by the manufacturer for all groups. Seventy two bovine teeth were divided in 2 groups (n=36) according to the polymerization system (halogen or LED) and subdivided (n=12) according to the debond time. For the halogen groups light-cure time was 20 seconds and for the LED groups light-cure time was 10 seconds. The shear bond test was performed with a universal testing machine at the different times of immediately, 24 hours and 7 days after bonding. Mean values of SBS for the halogen groups was (20,01±5,24 MPa) and (17,35±5,07MPa) for the LED groups with statistical difference between the groups. When comparing the different debond times, results revealed that SBS were significantly greater for the 7 days period. Two-way ANOVA test showed no statistical difference between the co-relation of light source and debond times. Results of Tukey test revealed that the four experimental conditions established for the immediately and 24 hours times did not differ statistically, but differed for the seven day period with the halogen system. The LED seven day condition performed as an intermediately result. The Adhesive Remanescent Index revealed no significative differences among all groups. As a conclusion it is reliable that although halogen groups differed from LED groups, the SBS mean values are greater than those clinically accepted.
The objective of this in vitro study was to compare the effects of polymerization using halogen and LED system on shear bond strengths (SBS) at different debond times of immediately, 24 hours and 7 days after bonding. Pre-coated brackets (Gemini series; 3M Unitek, USA) were bonded to bovine incisors in all specimens. Teeth were conditioned with a self-etching primer (Transbond SEP, 3M Unitek, USA) as recommended by the manufacturer for all groups. Seventy two bovine teeth were divided in 2 groups (n=36) according to the polymerization system (halogen or LED) and subdivided (n=12) according to the debond time. For the halogen groups light-cure time was 20 seconds and for the LED groups light-cure time was 10 seconds. The shear bond test was performed with a universal testing machine at the different times of immediately, 24 hours and 7 days after bonding. Mean values of SBS for the halogen groups was (20,01±5,24 MPa) and (17,35±5,07MPa) for the LED groups with statistical difference between the groups. When comparing the different debond times, results revealed that SBS were significantly greater for the 7 days period. Two-way ANOVA test showed no statistical difference between the co-relation of light source and debond times. Results of Tukey test revealed that the four experimental conditions established for the immediately and 24 hours times did not differ statistically, but differed for the seven day period with the halogen system. The LED seven day condition performed as an intermediately result. The Adhesive Remanescent Index revealed no significative differences among all groups. As a conclusion it is reliable that although halogen groups differed from LED groups, the SBS mean values are greater than those clinically accepted.
Descrição
Palavras-chave
Ortodontia, LED, Braquetes ortodônticos, Resistência adesiva
Como citar
DI NICOLÓ, Rebeca. Avaliação in vitro da resistência adesiva de braquetes ortodônticos variando-se o tempo de armazenamento e o tipo de fotoativação: luz halógena e led. 2007. 129 f. Tese (Livre-docência) - Universidade Estadual Paulista, Faculdade de Odontologia de São José dos Campos, 2007.