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.

Classe II tratada com distalizador associado à ancoragem esquelética / Angle class II malocclusion treated with intraoral distalizer associated with skeletal anchorage

O caso relatado no presente artigo refere-se a uma paciente com má oclusão de Classe II de Angle que foi tratada em duas fases: a primeira consistindo na instalação de um distalizador intrabucal First Class modificado, associado a mini-implantes no palato e a segunda consistindo no aparelho fixo. A severidade da discrepância anteroposterior era moderada, com apinhamento leve em ambos os arcos, sem comprometimento esquelético significante. O aparelho promoveu distalização dos molares, bem como uma pequena perda de ancoragem nos dentes anteriores à distalização. A segunda fase com aparelho fixo visou promover o alinhamento e nivelamento dos arcos, bem como a retração anterior, auxiliada por uma ancoragem baseada em um botão de Nance associado aos mini-implantes. Ao final do tratamento foram observadas a correção da discrepância anteroposterior dos arcos, bem como uma oclusão balanceada e estética satisfatória.(AU)

The present case report refers to a patient with Angle Class II malocclusion who was treated in two phases: the first phase consisting of the installation of a modified First Class intraoral distalizer associated with mini implants on the palate, and the second phase consisting of a fixed appliance. The anteroposterior discrepancy severity was moderate, with light crowding in both arches, without significant skeletal component. The device promoted distalization of the molars, as well as a small loss of anchorage in the anterior teeth. The second phase with a fixed appliance promoted the alignment and leveling of the arches, as well as the anterior retraction, assisted by an anchorage reinforcement based on a Nance button associated to the mini implants. At the end of the treatment the anteroposterior discrepancy was corrected and a balanced and esthetic occlusion was observed.(AU)

Cantilever ancorado a mini implante para distalização de molares superiores / Cantilever with mini-screw for maxillary molar

Dentre as diversas formas de tratar a má oclusão de Classe II, a distalização de molares superiores com aparelhos intrabucais fixos é uma alternativa conservadora e com mínima necessidade de colaboração do paciente. O cantilever para distalização utilizado no presente caso clínico, confeccionado no Departamento de Ortodontia da Faculdade de Odontologia de Bauru, é ancorado a um mini-implante e tem o objetivo de ser um dispositivo simplificado, de fácil confecção, instalação e ativação. O objetivo deste relato de caso é apresentar as características deste distalizador e sua utilização em um paciente com má oclusão de Classe II, divisão 1. A relação molar de Classe I foi obtida no período de aproximadamente 5 meses, acompanhada de movimento distal dos pré-molares e sem provocar protrusão anterior.(AU)

Maxillary molar distalization with fixed intraoral appliances is a conservative alternative that requires minimal need of patient collaboration. The cantilever for molar distalization used in the present case report was made in the Department of Orthodontics of Bauru Dental School. It is anchored to a mini-screw and aims to be a simplified device, easy to make, to install and to activate. The objective of this case report is to present the characteristics of the distalizer and its use in a patient with Class II division 1 malocclusion. The Class I molar relationship was efficiently achieved after a period of 5 months, followed by premolars distal movement and overjet maintenance. (AU)

Evaluation of deflection forces of orthodontic wires with different ligation types

Abstract The aim of this study was to evaluate deflection forces of orthodontic wires of different alloys engaged into conventional brackets using several ligation types. Stainless steel, conventional superelastic nickel-titanium and thermally activated nickel-titanium archwires tied into conventional brackets by a ring-shaped elastomeric ligature (RSEL), a 8-shaped elastomeric ligature (8SEL) and a metal ligature (ML) were tested. A clinical simulation device was created especially for this study and forces were measured with an Instron Universal Testing Machine. For the testing procedure, the block representing the maxillary right central incisor was moved 0.5 and 1 mm bucco-lingually at a constant speed of 2 mm/min, and the forces released by the wires were recorded, in accordance with the ISO 15841 guidelines. In general, the RSEL showed lighter forces, while 8SEL and ML showed higher values. At the 0.5 mm deflection, the 8SEL presented the greatest force, but at the 1.0 mm deflection the ML had a statistically similar force. Based on our evaluations, to obtain lighter forces, the thermally activated nickel-titanium wire with the RSEL are recommended, while the steel wire with the 8SEL or the ML are recommended when larger forces are desired. The ML exhibited the highest force increase with increased deflections, compared with the elastomeric ligatures.

Evaluation of force released by deflection of orthodontic wires in conventional and self-ligating brackets

ABSTRACT Introduction: The aim of the study was to evaluate deflection forces of rectangular orthodontic wires in conventional (MorelliTM), active (In-Ovation RTM) and passive (Damon 3MXTM) self-ligating brackets. Material and Methods: Two brands of stainless steel and nickel-titanium (NiTi) wires (MorelliTM and GACTM), in addition to OrmcoTM copper-nickel-titanium wires were used. Specimens were assembled in a clinical simulation device especially designed for this study and tested in an Instron universal testing machine. For the testing procedures, an acrylic structure representative of the maxillary right central incisor was lingually moved in activations of 0 to 1 mm, with readings of the force released by deflection in unloading of 0.5, 0.8 and 1 mm at a constant speed of 2 mm/min. Inter-bracket forces with stainless steel, NiTi and CuNiTi were individually compared by two-way ANOVA, followed by Tukey’s tests. Results: Results showed that there were lower forces in conventional brackets, followed by active and passive self-ligating brackets. Within the brands, only for NiTi wires, the MorelliTM brand presented higher forces than GACTM wires. Conclusions: Bracket systems provide different degrees of deflection force, with self-ligating brackets showing the highest forces.

RESUMO Objetivo: o objetivo deste estudo foi avaliar as forças de deflexão de fios ortodônticos retangulares em braquetes convencionais (MorelliTM) e autoligáveis ativos (In-Ovation RTM ) e passivos (Damon 3MXTM). Material e Métodos: foram utilizadas duas marcas comerciais (MorelliTM e GACTM) de fios de aço inoxidável e de níquel-titânio (NiTi), além do fio de NiTi com adição de cobre (OrmcoTM). Os espécimes foram montados em um dispositivo de simulação clínica especialmente desenhado para esse estudo e testado em uma máquina universal de ensaios Instron. Para o procedimento dos testes, a peça representativa do incisivo central superior direito foi movida no sentido vestibulolingual em ativações de 0 a 1 mm, com leituras da força liberada pela deflexão em 0,5; 0,8 e 1 mm, em uma velocidade constante de 2 mm/min. As forças interbraquetes com os fios de aço, de NiTi e NiTi com adição de cobre foram individualmente comparadas pelo teste de ANOVA a dois critérios, seguido pelo teste de Tukey. Resultados: houve menor liberação de forças nos braquetes convencionais, seguidos pelos braquetes autoligáveis ativos e passivos. Entre as marcas comerciais, somente houve diferença para o fio de NiTi, onde a marca MorelliTM apresentou maiores forças do que a GACTM. Conclusão: os braquetes promovem diferentes graus de forças de deflexão, sendo que os braquetes autoligáveis liberam as maiores forças.

Influência de medicamentos e alterações sistêmicas na movimentação dentária e reabsorções associadas / The influence of drugs and systemic changes in tooth movement and resorption associated

O objetivo desta revisão de literatura foi discutir a influência de medicamentos e alterações sistêmicas na movimentação dentária induzida e reabsorções dentárias associadas. Em grande parte dos trabalhos experimentais, falta explicação de como a dosagem e a posologia foram escolhidas, além da variação quanto à intensidade e distribuição das forças aplicadas para se obter a movimentação dentária, e das espécies animais utilizadas. A falta de metodologia padronizada e alométrica dos estudos compromete os resultados obtidos, e dificulta a comparação dos mesmos. É necessário avaliar cuidadosamente os métodos experimentais dos estudos antes de extrapolar os resultados para a clínica ortodôntica. Durante o tratamento ortodôntico, as alterações sistêmicas, em especial as endocrinopatias (hipotireoidismo, hipertireoidismo, hiperparatireoidismo, hipoparatireoidismo, diabetes mellitus tipos 1 e 2, síndrome dos ovários policísticos e climatério), são empiricamente associadas a uma ação potencializadora das reabsorções dentárias. As causas da reabsorção dentária estão relacionadas com a perda dos cementoblastos da superfície radicular, e esta perda tem origem local. Estas células não têm receptores para mediadores sistêmicos e nem são alvos de ação secundária dos medicamentos. Com base em trabalhos metodologicamente planejados e executados, não se pode afirmar que haja alteração na movimentação dentária induzida e influência sobre o índice de reabsorções dentárias, causada pelo uso de analgésicos, anti-inflamatórios, corticoides, bisfosfonatos, anticoncepcionais ou alteração sistêmica durante o tratamento ortodôntico...

The objective of this review was to discuss the influence of drugs and systemic changes in induced tooth movement and associated root resorption. In most of the experimental works, there is a lack of explanation of how the dosage and dosage regimen was chosen, in addition to the variation in the intensity and distribution of forces applied to obtain tooth movement and the animal species used. The lack of standardized and allometric methodology of the studies compromises the results and makes it difficult to compare them. It is necessary to carefully evaluate the experimental methods of the studies before extrapolating the results to the orthodontic clinic. During orthodontic treatment the systemic changes, especially endocrine diseases such as hypothyroidism, hyperthyroidism, hyperparathyroidism, hypoparathyroidism, diabetes mellitus type 1 and 2, polycystic ovary syndrome and menopause are empirically associated with a potentiating action of root resorption. The causes of resorption are related to the loss of cementoblasts root surface, and this loss has local origin. These cells do not have receptors for systemic mediators nor are targets of secondary action of drugs. Based on methodological works planned and executed, it cannot be said that there is a change in induced tooth movement and influence on the root resorption index, caused by use of analgesics, anti-inflammatories, corticosteroids, bisphosphonates, birth or systemic change during treatment orthodontic...

Tratamento da má oclusão de Classe II com Distal Jet e aparelho fixo / Treatment of Class II malocclusion with the Distal Jet and fixed appliance

O presente relato de caso clínico refere-se a um tratamento de má oclusão de Classe II de Angle utilizando aparelho distalizador intrabucal Distal Jet. Este aparelho é considerado eficaz na correção dessa má oclusão e com boas alternativas para controlar os efeitos adversos oriundos do tratamento. O paciente apresentava má oclusão de Classe II divisão 1 sem componente esquelético significante. O aparelho foi eleito para este caso baseado na possível falta de colaboração do paciente e pela má oclusão encontrada. Na segunda fase do tratamento, o aparelho foi convertido em um botão de Nance para reforço de ancoragem e o aparelho fixo foi instalado com o objetivo de corrigir os efeitos colaterais resultantes da primeira fase. O aparelho extrabucal de uso noturno e elásticos de Classe II foram utilizados para evitar a mesialização dos molares durante esta fase. Ao final do tratamento foram observadas correção da relação molar, oclusão balanceada e estética.

The present case report refers to thetreatment of Angle Class II malocclusion using Distal Jet appliance. This device is considered effective in correcting this malocclusion, and has good alternatives to control the adverse effects arising from the treatment. The patient showed Class II division 1 malocclusion, without significant skeletal component. The device was cho-sen for the first phase of the treatment based on the possible lack of patient’s cooperation and the malocclusion presented. In the second phase, the Distal Jet was converted into a Nance button to reinforce the anchorage and the fixed appliance was installed to correct the side effects resulting from the first phase. The headgear for night use and Class II elastics were used to prevent mesial movement of the molars during this phase. At the end of the treatment, the molar relationship was corrected and a balanced and aesthetic occlusion was observed.