Evaluation of the force generated by gradual deflection of 0.016-inch NiTi and stainless steel orthodontic wires in self-ligating metallic and esthetic brackets

The purpose of this study was to evaluate the deflection forces of 0.016-inch Nitinol and stainless steel orthodontic wires, in association to different self-ligating brackets. Specimens were mounted in a clinical simulation model and evaluated in a Universal Testing Machine (INSTRON 3342), using a 10N load cell and ISO 15,841, as a protocol. Eight of these models were prepared, each one for the bonding of each set of self-ligating accessories to be tested: Damon Q, Damon Clear (Ormco), In-Ovation R, In-Ovation C (GAC), BioQuick, QuickClear (Forestadent), SmartClip and Clarity SL (3M). Data were subjected to One-way ANOVA, followed by Tukey tests (P<0.05). Elastic deflection results showed that the deactivation forces increased with increase in wire deflection in the different brackets evaluated. For the different combinations, Clarity SL generated the greatest force and Damon Clear presented the lowest force when compared to the other brackets in all alloys and deflections. BioQuick and QuicKlear were those with the most similar behavior with each other. Strength values increased with gradual increase in wire deflection in all evaluated brackets. Clarity SL generated the greatest and Damon Clear the lowest force when compared to the other brackets in all alloys and deflections tested

Comparison of deflection forces of esthetic archwires combined with ceramic brackets

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

Stability of the correction of the Class II, division 1 malocclusion with the Balters Bionator associated to fixed appliances

Recursos ortopédicos e ortodônticos, utilizados de forma associada, têm se mostrado uma opção terapêutica eficiente no tratamento da má oclusão de Classe II, 1ª divisão desde que o paciente ainda apresente um potencial de crescimento favorável. Entretanto, as alterações nas relações esqueléticas, dentárias e tegumentares só podem ser consideradas satisfatórias caso permaneçam estáveis. Assim, este trabalho teve o propósito de avaliar cefalometricamente e por meio de modelos de estudo, a estabilidade das alterações decorrentes do tratamento com o aparelho Bionator de Balters, seguido do aparelho fixo, após um período médio de 10 anos. O grupo experimental compreendeu 23 pacientes que foram avaliados em três fases: inicial (T1), final (T2) e longo tempo pós-tratamento (T3). Foram avaliadas as telerradiografias em norma lateral (inicial, final e longo tempo pós-tratamento), totalizando 69 telerradiografias, e foram mensurados 69 modelos de estudo, avaliados nas fases previamente descritas, através do índice PAR. Também calculou-se a diferença entre o PAR inicial e o PAR final, a % de melhora obtida com esta terapia e a % de recidiva, ambas através do índice PAR. As variáveis analisadas foram comparadas por meio da análise de variância (ANOVA) para medidas repetidas e o teste de comparações múltiplas de Tukey. A terapia estudada não propiciou alterações no desenvolvimento maxilar. Observou-se um aumento na protrusão mandibular, bem como um maior incremento no comprimento efetivo da mandíbula. A relação maxilomandibular foi corrigida, notou-se uma melhora na convexidade facial, com a diminuição do ângulo ANB. Alterações significantes no padrão de crescimento craniofacial não foram observadas. Verificou-se, através da variável FMA e no período de longo tempo pós-tratamento, uma rotação do plano mandibular no sentido anti-horário. O posicionamento vertical da maxila (SN.PP) também não se alterou. Os incisivos superiores sofreram lingualização e retrusão. Os primeiros molares superiores mostraram um pequeno aumento no sentido vertical semelhante ao fisiológico, que ocorre pelo processo de flutuação normal. Em contrapartida, os incisivos inferiores sofreram vestibularização e protrusão. Os primeiros molares inferiores, por sua vez, apresentaram um deslocamento no sentido vertical (extrusão) e horizontal (mesialização), contribuindo, assim, para a correção da má-oclusão de Cl II. O tratamento também foi efetivo em corrigir os respasses, horizontal e vertical, bem como a relação molar. O ângulo nasolabial não foi afetado pelo tratamento, mostrando que os aparelhos ortopédicos não afetam substancialmente esta variável. Além disso, é de suma importância, ressaltarmos que, as alterações obtidas, com o tratamento realizado, permaneceram estáveis no período de longo tempo pós-tratamento; demostrando, dessa maneira, a efetividade da terapia selecionada. Finalmente, na análise dos modelos de estudo, os valores do índice PAR sofreram uma redução estatisticamente significante e permaneceram estáveis no período de longo tempo pós-tratamento. A porcentagem de melhora obtida com esta terapia foi de 81,78% e a de recidiva foi de 4,90%. Esses dados refletem que o Bionator de Balters, associado ao aparelho fixo, é uma efetiva alternativa para o tratamento da má-oclusão de Cl II, 1ª divisão.Orthopedic and orthodontic approaches, used in an associated way, are being considered an efficient therapeutic option for the treatment of the Class II, division 1 malocclusion when the patient still presents a favorable growth potential. However, changes in skeletal, dental and soft tissue relationships only can be considered satisfactory if they remain stable. This study aimed to evaluate, cephalometrically and in dental casts, the stability of the changes resulting from the treatment with the Balters Bionator followed by the fixed appliances, after a mean period of 10 years. The experimental group comprised 23 patients who were evaluated in three stages: initial (T1), final (T2) and long-term posttreatment (T3). A total of 69 lateral cephalograms (initial, final and long-term posttreatment) were evaluated and also 69 dental casts were measured, in the stages previously described, using the PAR index. Furthermore, the difference between initial PAR and final PAR, the percentage of obtained improvement with the therapy and the percentage of relapse were calculated, using the PAR index. Evaluated variables were compared by the analysis of variance (ANOVA) for repeated measures and Tukey test. The studied therapy did not provide changes in maxillary development. An increase in mandibular protrusion, as well as a greater increase in effective length of the mandible, was observed. The maxillomandibular relationship was corrected, and an improvement in the facial convexity was observed, with a decrease of the ANB angle. Significant changes in craniofacial growth were not observed. The analysis of the FMA variable and of the long-term posttreatment revealed a rotation of the mandibular plane in a counterclockwise direction. The vertical positioning of the maxilla (SN.PP) also did not change. The maxillary incisors presented a palatal inclination and retrusion. The maxillary first molars showed a small increase in the vertical direction, similar to the physiological one, which occurred by the normal fluctuation process. In contrast, the mandibular incisors presented a buccal inclination and protrusion. The mandibular first molars showed a displacement in the vertical (extrusion) and horizontal (mesial) direction, which contributed to the correction of the Class II malocclusion. The treatment was also effective in correcting the overbite and overjet, and the molar relationship. The nasolabial angle was not affected by treatment, showing that orthopedic appliances did not significantly affect this variable. Finally, the analysis of the dental casts showed that the values of the PAR index presented a statistically significant reduction and remained stable at the long-term posttreatment. The percentage of improvement obtained with this therapy was of 81.78% and the percentage of relapse was of 4.90%. These data denote that Balters Bionator associated to the fixed appliances is an effective alternative for the treatment of the Class II, division 1 malocclusion

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 os braquetes avaliados. Os braquetes autoligáveis foram os que apresentaram os resultados mais constantes e previsíveis enquanto que nos demais essa característica não foi observada.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 predictable results while for others kinds of brackets such pattern was not observed

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

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 (

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

Force level of small diameter nickel-titanium orthodontic wires ligated with different methods

Abstract Background The aim of this study was to compare the deflection force in conventional and thermally activated nickel-titanium (NiTi) wires in passive (Damon Q) and active (Bioquick) self-ligating brackets (SLB) and in conventional brackets (CB) tied by two different methods: elastomeric ligature (EL) and metal ligature (ML). Methods Two wire diameters (0.014 and 0.016 in.) and 10 specimens per group were used. The specimens were assembled in a clinical simulation device and tested in an Instron Universal Testing Machine, with a load cell of 10 N. For the testing procedures, the acrylic block representative of the right maxillary central incisor was palatally moved, with readings of the force at 0.5, 1, 2, and 3 mm, at a constant speed of 2 mm/min and temperature of 36.5 °C. Results The conventional NiTi released higher forces than the thermally activated NiTi archwires in large deflections. In general, the SLB showed lower forces, while the ML had higher forces, with both showing a similar force release behavior, constantly decreasing as the deflection decreased. The EL showed an irregular behavior. The active SLB showed smaller forces than passive, in large deflections. Conclusions The SLB and the ML exhibit standard force patterns during unloading, while the elastomeric ligatures exhibit a randomly distributed force release behavior

Comparison of deflection forces of esthetic archwires combined with ceramic brackets

<div><p>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.</p></div