Comparison of deflection forces of esthetic archwires combined with ceramic brackets

Abstract Coated archwires and ceramic brackets have been developed to improve facial esthetics during orthodontic treatment. However, their mechanical behavior has been shown to be different from metallic archwires and brackets. Therefore, the aim of this study was to compare the deflection forces in coated nickel-titanium (NiTi) and esthetic archwires combined with ceramic brackets. Material and Methods Non-coated NiTi (NC), rhodium coated NiTi (RC), teflon coated NiTi (TC), epoxy coated NiTi (EC), fiber-reinforced polymer (FRP), and the three different conventional brackets metal-insert polycrystalline ceramic (MI-PC), polycrystalline ceramic (PC) and monocrystalline ceramic (MC) were used. The specimens were set up on a clinical simulation device and evaluated in a Universal Testing Machine (Instron). An acrylic device, representative of the right maxillary central incisor was buccolingually activated and the unloading forces generated were recorded at 3, 2, 1 and 0.5 mm. The speed of the testing machine was 2 mm/min. ANOVA and Tukey tests were used to compare the different archwires and brackets. Results The brackets presented the following decreasing force ranking: monocrystalline, polycrystalline and polycrystalline metal-insert. The decreasing force ranking of the archwires was: rhodium coated NiTi (RC), non-coated NiTi (NC), teflon coated NiTi (TC), epoxy coated NiTi (EC) and fiber-reinforced polymer (FRP). At 3 mm of unloading the FRP archwire had a plastic deformation and produced an extremely low force in 2; 1 and 0.5 mm of unloading. Conclusion Combinations of the evaluated archwires and brackets will produce a force ranking proportional to the combination of their individual force rankings.

Evaluation of the force generated by gradual deflection of orthodontic wires in conventional metallic, esthetic, and self-ligating brackets

ABSTRACT Objective: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires placed in different types of brackets: metallic, reinforced polycarbonate with metallic slots, sapphire, passive and active self-ligating, by assessing strength values variation according to gradual increase in wire diameter and deflection and comparing different combinations in the different deflections. Material and Methods: Specimens were set in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using the ISO 15841 protocol. Data were subjected to One-way ANOVA, followed by Tukey tests (p<0.05). Results: Self-ligating brackets presented the most similar behavior to each other. For conventional brackets there was no consistent behavior for any of the deflections studied. Conclusions: Self-ligating brackets presented the most consistent and predictable results while conventional brackets, as esthetic brackets, showed very different patterns of forces. Self-ligating brackets showed higher strength in all deflections when compared with the others, in 0.020-inch wires.

Avaliação da força gerada pela deflexão gradual de fios ortodônticos em braquetes convencionais metálicos, estéticos e autoligáveis / Evaluation of the force generated by gradual deflection of orthodontic wires in conventional mettalic, esthetic and self-ligated brackets

PROPOSIÇÃO: O objetivo deste trabalho foi avaliar a força gerada pela deflexão de fios ortodônticos de Nitinol associados a diferentes tipos de braquetes por meio da avaliação dos valores da força através do aumento gradual do calibre e da deflexão dos fios e comparação entre as distintas combinações, nas diferentes deflexões. MATERIAL E MÉTODOS: Os corpos de prova foram montados em um modelo de simulação clínica e avaliados em uma máquina de ensaio universal INSTRON 3342, com célula de carga de 10N e, como protocolo, foi seguida a norma ISO 15.841. Foram confeccionados cinco destes modelos para a colagem de cada conjunto de acessórios a serem testados: metálico (Mini Diamond), policarbonato com fibra de vidro e canaleta metálica (Spirit), safira (Inspire ICE) e os autoligáveis passivo (Damon Q/Ormco) e ativo (In-Ovation R/GAC). Para os testes, o dispositivo de acrílico que representava o incisivo central direito foi movimentado no sentido palatino-vestibular, com leituras das resistências geradas nas deflexões de 3; 2; 1 e 0,5mm, com velocidade constante de 2mm/min. Os resultados foram avaliados por meio da análise de variância (ANOVA) a dois e a um critério, havendo diferença significante, a análise comparativa das médias foi feita por meio do teste de Tukey (p<0,05). RESULTADOS: A força de desativação foi gradativamente maior, com o aumento do calibre dos arcos e maior deflexão, nos diferentes tipos de braquetes. Nas combinações entre os diferentes tipos de braquetes selecionados com os fios de Nitinol verificou-se que os braquetes autoligáveis foram os que apresentaram os resultados mais parecidos entre si, mantendo-os decrescentes conforme a deflexão diminuía. Já, entre os braquetes convencionais Mini Diamond, Spirit e Inspire ICE verificou-se que não existe um padrão em nenhuma deflexão estudada. CONCLUSÕES: A avaliação dos valores da força, através do aumento gradual do calibre e da deflexão dos fios, demonstrou que a mesma foi crescente em todos...

OBJECTIVE: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires, placed in different kinds of brackets by assessing strength values variation according to gradual increase in the diameter and the deflection of the wires, comparing the different combinations, in the different deflections. MATERIAL AND METHODS: Specimens were mounted in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using a 10 N load cell and, as a protocol, ISO 15841. Five of these models were prepared, each one for the bonding of each set of accessories to be tested: metallic (Mini Diamond), reinforced polycarbonate with metallic slots (Spirit), sapphire (Inspire ICE), and passive (Damon Q/Ormco) and active self-ligated (In-Ovation R/GAC). For performing the tests, the acrylic device corresponding to the right central incisor was moved in the buccal-lingual direction, and values of resistance generated for 3, 2, 1 and 0.5mm deflections, at a constant speed of 2mm/min, were registered. Data were subjected to Oneand Two-way ANOVA; since significant differences were observed, comparative analysis of mean values was performed by Tukey's post hoc test (p<0.05). RESULTS: Elastic deflection results showed that deactivation force increased with increase in the diameter of the wires and deflection in the different brackets evaluated. For the combinations of the different types of brackets with the Nitinol wires, it was found that self-ligating brackets were those with the most similar results to each other, which decreased as the deflection was decreased. For Mini Diamond, Spirit and Inspire ICE conventional brackets there was no pattern for any of the deflections studied. CONCLUSIONS: Strength values evaluation according to gradual increase in the diameter and the deflection of the wires showed that it increased in all evaluated brackets. Self-ligating brackets were those which presented the most consistent and...

Avaliação da força gerada pela deflexão gradual de fios ortodônticos em braquetes convencionais metálicos, estéticos e autoligáveis / Evaluation of the force generated by gradual deflection of orthodontic wires in conventional mettalic, esthetic and self-ligated brackets

PROPOSIÇÃO: O objetivo deste trabalho foi avaliar a força gerada pela deflexão de fios ortodônticos de Nitinol associados a diferentes tipos de braquetes por meio da avaliação dos valores da força através do aumento gradual do calibre e da deflexão dos fios e comparação entre as distintas combinações, nas diferentes deflexões. MATERIAL E MÉTODOS: Os corpos de prova foram montados em um modelo de simulação clínica e avaliados em uma máquina de ensaio universal INSTRON 3342, com célula de carga de 10N e, como protocolo, foi seguida a norma ISO 15.841. Foram confeccionados cinco destes modelos para a colagem de cada conjunto de acessórios a serem testados: metálico (Mini Diamond), policarbonato com fibra de vidro e canaleta metálica (Spirit), safira (Inspire ICE) e os autoligáveis passivo (Damon Q/Ormco) e ativo (In-Ovation R/GAC). Para os testes, o dispositivo de acrílico que representava o incisivo central direito foi movimentado no sentido palatino-vestibular, com leituras das resistências geradas nas deflexões de 3; 2; 1 e 0,5mm, com velocidade constante de 2mm/min. Os resultados foram avaliados por meio da análise de variância (ANOVA) a dois e a um critério, havendo diferença significante, a análise comparativa das médias foi feita por meio do teste de Tukey (p<0,05). RESULTADOS: A força de desativação foi gradativamente maior, com o aumento do calibre dos arcos e maior deflexão, nos diferentes tipos de braquetes. Nas combinações entre os diferentes tipos de braquetes selecionados com os fios de Nitinol verificou-se que os braquetes autoligáveis foram os que apresentaram os resultados mais parecidos entre si, mantendo-os decrescentes conforme a deflexão diminuía. Já, entre os braquetes convencionais Mini Diamond, Spirit e Inspire ICE verificou-se que não existe um padrão em nenhuma deflexão estudada. CONCLUSÕES: A avaliação dos valores da força, através do aumento gradual do calibre e da deflexão dos fios, demonstrou que a mesma foi crescente em todos...

OBJECTIVE: The purpose of this study was to evaluate the deflection forces of Nitinol orthodontic wires, placed in different kinds of brackets by assessing strength values variation according to gradual increase in the diameter and the deflection of the wires, comparing the different combinations, in the different deflections. MATERIAL AND METHODS: Specimens were mounted in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using a 10 N load cell and, as a protocol, ISO 15841. Five of these models were prepared, each one for the bonding of each set of accessories to be tested: metallic (Mini Diamond), reinforced polycarbonate with metallic slots (Spirit), sapphire (Inspire ICE), and passive (Damon Q/Ormco) and active self-ligated (In-Ovation R/GAC). For performing the tests, the acrylic device corresponding to the right central incisor was moved in the buccal-lingual direction, and values of resistance generated for 3, 2, 1 and 0.5mm deflections, at a constant speed of 2mm/min, were registered. Data were subjected to Oneand Two-way ANOVA; since significant differences were observed, comparative analysis of mean values was performed by Tukey's post hoc test (p<0.05). RESULTS: Elastic deflection results showed that deactivation force increased with increase in the diameter of the wires and deflection in the different brackets evaluated. For the combinations of the different types of brackets with the Nitinol wires, it was found that self-ligating brackets were those with the most similar results to each other, which decreased as the deflection was decreased. For Mini Diamond, Spirit and Inspire ICE conventional brackets there was no pattern for any of the deflections studied. CONCLUSIONS: Strength values evaluation according to gradual increase in the diameter and the deflection of the wires showed that it increased in all evaluated brackets. Self-ligating brackets were those which presented the most consistent and...

Stability of Class II treatment with the Bionator followed by fixed appliances

Objective: This prospective study assessed the stability of Class II treatment with the Bionator, followed by fixed appliances, 10 years after treatment. Material and Methods: The experimental group comprised 23 patients of both sexes (10 boys, 13 girls) at a mean initial age of 11.74 years (late mixed or early permanent dentitions), treated for a mean period of 3.55 years who were evaluated at three stages: initial (T1), final (T2) and long-term posttreatment (T3). A total of 69 lateral cephalograms were evaluated and 69 dental casts were measured using the PAR index. The difference between initial and final PAR indexes, the percentage of occlusal improvement obtained with therapy and the percentage of relapse were calculated, using the PAR index. The variables were compared by repeated measures analysis of variance (ANOVA) followed by Tukey tests. Results: The significant improvement in apical base relationship, the palatal inclination of the maxillary incisors and the labial inclination of the mandibular incisors, and the significant improvement in molar relationship and reduction of overjet and overbite, obtained with treatment, remained stable in the long-term posttreatment period. There was also significant improvement in the occlusal relationships which remained stable in the long-term posttreatment period. The percentage of occlusal improvement obtained was of 81.78% and the percentage of relapse was of 4.90%. Conclusions: Treatment of Class II division 1 malocclusions with the Bionator associated with fixed appliances showed to be stable in the long-term posttreatment period. .

Propriedades dos fios de NiTi superelásticos termicamente ativados – uma revisão literária / Properties of thermally activated superelastic NiTi archwires – a literature review

A utilização de fios de níquel-titânio superelásticos (NiTi) consiste em uma nova opção disponível no mercado mundial para tratamentos ortodônticos, o que torna necessária a reunião de informações que possa auxiliar na tomada de decisões dos ortodontistas quanto à sua utilização ou não, conforme o caso clínico a ser trabalhado. Diante disso, são apresentadas, nesta revisão de literatura, algumas informações científicas sobre os fios de NiTi termicamente ativados, bem como suas propriedades físicas, suas diferenças entre carga e deflexão, e os resultados de alguns testes realizados. São discutidos aspectos quanto à melhor fase de utilização desses fios e, dentre as marcas que estão disponíveis no mercado, quais são as mais adequadas para a utilização nas diferentes fases de tratamento.

Superelastic nickel-titanium (NiTi) archwires are a brand new marketable option for orthodontic treatment, which makes the discussion of scientific information regarding their use essential in helping professionals to plan and perform evidence-based treatments. Therefore, this literature review ponders scientific information related to thermally activated superelastic NiTi archwires, taking into account their physical properties, the differences between load and deflection and the results of some accomplished studies. The moment best indicated for their application and, among the available trademarks, the most suitable ones for each treatment phase are mainly discussed.

Mordida aberta anterior: etiologia e tratamento / Anterior open bite: etiology and treatment

Os hábitos bucais deletérios interferem no desenvolvimento normal da oclusão e sua persistência induz más oclusões sendo, a mordida aberta, a mais freqüente. Quanto mais precoce o tratamento, menor a possibilidade de recidiva e maior a estabilidade. Dois relatos de casos foram apresentados. O primeiro caso mostra um plano de tratamento, em dentição mista, iniciado com a instalação do aparelho interceptador removível, com parafuso expansor, grade palatina, arco vestibular ativação dos grampos de Adams nos primeiros molares permanentes e grampos auxiliares entre os molares decíduos. O tratamento durou 5 meses. No segundo caso a paciente com dentição permanente apresentava má oclusão de Classe II divisão 1 subdivisão direita. Os dentes 16, 26, 36 e 46 foram bandados com os seus respectivos tubos voltados para a cervical, para a adaptação do arco extrabucal AEB (IHG) e uma PLA (Placa Lábio Ativa). Foi instalado o aparelho Hyrax, dento-suportado construído com fios rígidos e com parafuso o mais próximo possível do palato. Em seguida a remoção do disjuntor, foi feita uma avaliação e realizada as extrações dos dentes 14, 24 e 34 com finalidade de eliminar a discrepância dentária e cefalometria, corrigindo, assim, a linha média do paciente. O alinhamento e o nivelamento dos dentes foram realizados com fios redondos com periodicidade, durante o período de 8 meses e a contenção utilizada foi a mesma dos tratamentos ortodônticos convencionais com a placa de Hawley superior e barra 3x3 inferior. O tratamento foi de três anos.