Does the composite attachment of clear aligners compromise the effectiveness of dental bleaching? An in vitro study.

INTRODUCTION: This study aimed to evaluate the effectiveness of dental bleaching with hydrogen peroxide 35% on the surface below the attachments. METHODS: Twenty-four blocks of bovine incisors were equally divided into 2 groups. The control group comprises the enamel surface free of attachments, whereas the attachment group comprises the enamel surface with attachment. Initial staining of samples was performed with black tea for 7 days; then, an attachment was made in the attachment group with Z250 resin and new staining for another 7 days in all samples. After staining, in-office bleaching was performed in both groups, and the attachments from the attachment group were removed. Color reading was performed with a spectrophotometer at all stages: initial (baseline), after 7 days of staining, after 14 days of staining, after immediate bleaching, and after 24 hours of bleaching. The color difference was calculated, and data analysis was performed using the t test for intergroup analysis. RESULTS: The results showed effective bleaching in both groups; however, there was a statistically significant difference in color change between them 24 hours after bleaching. CONCLUSION: It was concluded that the presence of attachment did not impair the action of the bleaching agent on the tooth surface.

Post-COVID-19 influence in orthodontic care from the patient's perspective / Influência nos cuidados ortodônticos, pós-COVID 19, na perspectiva do paciente

Objective: considering the behavioral and paradigm changes due to the social isolation imposed by the new coronavirus pandemic, patients and orthodontists also have anxieties and insecurities in face of the new reality in dental clinics and educational institutions. This study aimed to evaluate, by means of an online questionnaire, the applicability of tele-orthodontics and tele-assistance, the behavior of patients regarding the initiation of or return to orthodontic treatment, and the new changes in clinical care. Material and Methods: the questionnaire was based on the Google Forms platform and consisted of three parts: the first one involved study presentation and informed consent form; the second one involved demographic data collection and characterization of the respondents, and the third one was the questionnaire itself. The questionnaire was sent by email and instant-messaging apps, with data being submitted for descriptive analyzis. Results: a total of 116 replies were returned, and most of the respondents were aged between 18 and 30 years old, female, and residents of the Southeast region. The results showed that tele- orthodontics is still unknown to a significant number of patients (66.4%) and almost half of them (41.4%) want their treatments to be monitored in person, even those whose devices do not require activation. They also prefer the first consultation and diagnosis to be done in person (55.2%). However, they are receptive to the idea of having their data and images transmitted via the Internet, including some remote consultations interspersed with in-person ones, understanding that costs can be lowered. Conclusion: tele-orthodontics is a reality, but for orthodontic patients, its applicability remains restricted to sending images and records (AU)

Objetivo: considerando as mudanças comportamentais e de paradigmas decorrentes do isolamento social imposto pela pandemia do novo coronavírus, pacientes e ortodontistas também apresentam ansiedades e inseguranças diante da nova realidade nas clínicas odontológicas e instituições de ensino. Este estudo teve como objetivo avaliar, por meio de questionário online, a aplicabilidade da teleortodontia e da teleassistência, o comportamento dos pacientes quanto ao início ou retorno do tratamento ortodôntico e as novas mudanças no atendimento clínico. Material e Métodos: o questionário baseou-se na plataforma 'Google Forms" e foi constituído por três partes: a primeira envolveu a apresentação do estudo e o termo de consentimento livre e esclarecido; a segunda envolveu a coleta de dados demográficos e caracterização dos respondentes, e a terceira foi o próprio questionário. O questionário foi enviado por e-mail e aplicativos de mensagens instantâneas, sendo os dados encaminhados para análise descritiva. Resultados: foram devolvidas 116 respostas, sendo a maioria dos respondentes com idade entre 18 e 30 anos, do sexo feminino e residentes na região Sudeste. Os resultados mostraram que a teleortodontia ainda é desconhecida por um número significativo de pacientes (66,4%) e quase metade deles (41,4%) deseja que seus tratamentos sejam acompanhados presencialmente, mesmo aqueles cujos aparelhos não requerem ativação. Preferem também que a primeira consulta e diagnóstico seja presencial (55,2%). No entanto, eles estão receptivos à idéia de ter seus dados e imagens transmitidos pela Internet, incluindo algumas consultas à distância intercaladas com as presenciais, entendendo que os custos podem ser reduzido. Conclusão: a teleortodontia é uma realidade, mas para os pacientes ortodônticos sua aplicabilidade permanece restrita ao envio de imagens e registros (AU)

Deficiências biomecânicas dos alinhadores ­ dentes posteriores / Biomechanical limitations of clear aligners ­ posterior teeth

Resumo Nos últimos anos, um número crescente de pacientes adultos tem procurado tratamento ortodôntico e expressado o desejo de alternativas estéticas e confortáveis aos aparelhos fixos convencionais. A possibilidade de usar aparelhos ortodônticos transparentes foi introduzida em 1946, quando Kesling desenvolveu o conceito de usar uma série de posicionadores termoplásticos para mover progressivamente os dentes desalinhados para as posições corretas. Contudo, as deficiências biomecânicas próprias dos alinhadores levaram a se desenvolver, além de planejamentos digitais customizados e inteligentes, ferramentas auxiliares, como attachments otimizados, ancoragem esquelética e tratamentos híbridos combinados com aparelhos fixos com arco contínuo ou segmentado, os quais podem ser incorporados antes, durante ou após o uso dos alinhadores, permitindo que os objetivos ideais pretendidos sejam alcançados. Para ilustrar, apresentamos um caso clínico de segundos molares superiores posicionados em mordida cruzada, torque lingual de coroa e giroversão para mesial, corrigidos com mecânica segmentada, utilizando fios retangulares de TMA com alças em "T" para obtenção de um melhor controle tridimensional do movimento (AU)

Abstract In recent years, an increasing number of adult patients are seeking orthodontic treatment and have expressed a desire for esthetic and comfortable alternatives to conventional fixed appliances. The possibility of using orthodontic clear aligners was introduced by Kesling, in 1946, with the concept of a thermoplastic positioners to progressively move misaligned teeth into correct positions. However, the biomechanical limitations of clear aligners led to the development of auxiliary tools, such as optimized attachments, skeletal anchorage and hybrid treatments combined with fixed appliances with continuous or segmented arches, which can be incorporated before, during, or after the use of the clear aligners. To illustrate, we present a clinical case of maxillary second molars positioned in crossbite, crown lingual torque and mesial rotation, corrected with segmented mechanics, using rectangular TMA archwires with "T" loops to obtain a better three-dimensional control of the movement (AU)

Passo a passo do planejamento digital para confecção de alinhadores ortodônticos in office / Step-by-step digital planning for in office orthodontic aligners

Resumo Nos últimos anos, a rotina dos ortodontistas vem sendo impactada com o desenvolvimento da tecnologia de softwares de planejamento ortodôntico digital. Por ser uma excelente ferramenta para diagnóstico e planejamento para qualquer técnica ortodôntica e ser um passo fundamental do tratamento ortodôntico com alinhadores transparentes, é importante a adequação a essa nova realidade e rotina clínica. Esse pode ser um processo lento e pode significar trabalho árduo e um grande sacrifício por parte de profissionais menos adeptos à tecnologia ou com pouca experiência e conhecimento dos processos necessários. Este estudo propôs orientar o ortodontista e conduzi-lo, por meio de um passo a passo, ao conhecimento e aplicação do fluxo de planejamento digital (workflow), tendo em vista que essas dificuldades podem representar uma barreira para o desenvolvimento profissional. Foram descritas as etapas que devem ser seguidas no processo de tratamento ortodôntico com alinhadores, explicando e elucidando as ferramentas de planejamento virtual utilizadas em softwares gratuitos ou pagos, disponíveis no momento de desenvolvimento desse trabalho. Concluiu-se que o workflow exige conhecimento ortodôntico, além de uma abordagem técnica e apresenta 9 estágios que devem ser rigorosamente seguidos e executados de maneira sequencial e com atenção.(AU)

Abstract Over the last years the orthodontist's routine has been impacted by the development of digital orthodontic planning software technology. As an excellent tool for diagnosis and planning for any orthodontic technique and as a fundamental step in orthodontic treatment with clear aligners, it is necessary to adapt to this new reality and clinical routine. However, this can be a slow process and may require demanding work and a great sacrifice on the part of professionals who are less adept at the technology or with little experience and knowledge of the necessary processes. This article aimed to guide orthodontists through a step-by-step approach to the knowledge and application of digital planning flow (workflow) since these difficulties can represent a barrier to professional development. The steps that should be followed in the process of orthodontic treatment with aligners were described, explaining, elucidating the virtual planning tools used in free or paid software, available at the time of developing this work. It was concluded that workflow requires orthodontic knowledge, in addition to a technical approach, and has nine stages which should be strictly followed and executed in a sequential and careful manner. (AU)

Laser-photobiomodulation on titanium implant bone healing in rat model: comparison between 660- and 808-nm wavelength.

Laser-photobiomodulation (L-PBM) has been widely studied and its biomodulatory effects have been established on irradiated cells, increasing viability and proliferation and on damaged tissues. In addition, L-PBM may reduce and modulate the inflammatory process. The effect of 660-nm and 808-nm laser-photobiomodulation on bone repair around titanium dental implants placed in rat's femur was evaluated by histomorphometry. Twenty-seven Wistar rats were divided into 3 groups of nine animals: group C - non-irradiated control; group R - λ=660nm irradiated; and group IR - λ=808nm irradiated. Each group was further divided in 3 subgroups of three animals each, according to histomorphometry analysis in 3 days, 7 days, and 14 days after irradiation. Histological H.E.-stained slides were photographed, and bone matrix measured in new-formed bone area. Bone matrix histomorphometry analysis indicates that at 7 days in the irradiated groups (R and IR), a bigger area matrix was observed in relation to control group (C) (p=0.04 and p=0.048 respectively). On the other hand, at 14 days, control group (C) presented a bigger area than infrared irradiated (IR) (p=0.001) and red irradiated group (R) also showed a bigger area than infrared irradiated group (IR) (p=0.019). Histological analysis indicates that irradiated groups (R and IR) exhibited a faster bone tissue matrix production than control group.

Reference standard thickness for bone plates of upper teeth: an ultra-high-resolution study using tomographic mapping / Padrão de referência de espessura para cristas ósseas de dentes superiores: um estudo de ultra-alta resolução usando mapeamento tomográfico

Objective: it is important to know the thicknesses of the alveolar bone plates (ABPs) based on the current literature for the planning and success of orthodontic treatment. However, studies have scientific limitations regarding ABPs as the image resolution is not adequate and is restricted to a few teeth or buccal face only. This study was aimed at reporting a reference standard for bone plates of upper teeth, in which 15 patients (mean age of 21.79 years) with balanced occlusion and a harmonious facial profile were evaluated using cone-beam computed tomography at a voxel size of 0.1 mm. Material and Methods: bone tissues of the cervical, middle, and apical thirds of the root (buccal and palatal), the distance between cement-enamel junction (CEJ) and alveolar bone crest (ABC), and inclination of the teeth to the palatal plane were evaluated. Paired t-test, Spearman's correlation tests, and linear regression tests were used (P < 0.05). Results: the buccal distance between the CEJ and ABC was greater than the palatal one in all pairs of teeth. Most of the bone tissues had a thickness ≤ 1 mm in the buccal face, whereas in the cervical-apical direction, the thickness was ≥ 2 mm. There is no equivalence between genders in the sample. Conclusion: the reduced buccal bone architecture around the first premolars was indicative of local gingival recessions, and the lack of gender uniformity was suggestive of individual evaluation. References of normal bone tissue determining the orthodontic limits were provided to assist in the treatment planning. (AU)

Objetivo: é importante conhecer as espessuras das cristas ósseas alveolares (COAs) com base na literatura atual para o planejamento e sucesso do tratamento ortodôntico. No entanto, os estudos apresentam limitações científicas em relação às COAs, pois a resolução da imagem não é adequada e está restrita apenas a alguns dentes ou face vestibular. Este estudo teve como objetivo descrever um padrão de referência para corticais ósseas de dentes superiores, no qual 15 pacientes (idade média de 21,79 anos) com oclusão equilibrada e perfil facial harmonioso foram avaliados por meio de tomografia computadorizada de feixe cônico no tamanho de voxel de 0,1 mm. Material e Métodos: os tecidos ósseos dos terços cervical, médio e apical da raiz (vestibular e palatina), a distância entre a junção cemento-esmalte (JCE) e a crista óssea alveolar (COA) e a inclinação dos dentes ao plano palatino foram avaliados. Foram utilizados o teste t pareado, os testes de correlação de Spearman e os testes de regressão linear (P < 0,05). Resultados: a distância vestibular entre a JEC e a COA foi maior que a palatina em todos os pares de dentes. A maioria dos tecidos ósseos apresentou espessura ≤ 1 mm na face vestibular, enquanto no sentido cérvico-apical a espessura foi ≥ 2 mm. Não há equivalência entre os gêneros na amostra. Conclusão: a arquitetura óssea vestibular reduzida ao redor dos primeiros pré-molares foi indicativa de recessões gengivais locais, e a falta de uniformidade de gênero foi sugestiva de avaliação individual. Referências de tecido ósseo normal determinando os limites ortodônticos foram fornecidas para auxiliar no planejamento do tratamento. (AU)

Miniscrew insertion sites of infrazygomatic crest and mandibular buccal shelf in different vertical craniofacial patterns: A cone-beam computed tomography study.

OBJECTIVE: To identify optimal areas for the insertion of extra-alveolar miniscrews into the infrazygomatic crest (IZC) and mandibular buccal shelf (MBS), using cone beam computed tomography (CBCT) imaging in patients with different craniofacial patterns. METHODS: CBCT reconstructions of untreated individuals were used to evaluate the IZC and MBS areas. The participants were divided into three groups, based on the craniofacial pattern, namely, brachyfacial (n = 15; mean age, 23.3 years), mesofacial (n = 15; mean age, 19.24 years), and dolichofacial (n = 15; mean age, 17.79 years). In the IZC, the evaluated areas were at 11, 13, and 15 mm above the buccal cusp tips of the right and left first molars. In the MBS, the evaluated areas were at the projections of the first molars' distal roots and second molars' mesial and distal roots, at a 4- and 8-mm distance from the cementoenamel junction. Intergroup comparisons were performed with analysis of variance and the Tukey test. RESULTS: There was no statistically significant difference in the IZC bone thickness among the groups. For MBS bone availability, some comparisons revealed no difference; meanwhile, other comparisons revealed increased MBS bone thickness in the brachyfacial (first molars distal roots) and dolichofacial (second molars mesial and distal roots) patterns. CONCLUSIONS: There was no significant difference in the IZC bone thickness among the groups. The facial skeletal pattern may affect the availability of ideal bone thickness for the insertion of extra-alveolar miniscrews in the MBS region; however, this variability is unlikely to be clinically meaningful.

Predictors of orthodontic treatment conclusion: A historical cohort study.

INTRODUCTION: The study investigated which patient and orthodontic treatment factors act as predictors for the conclusion of the ongoing treatment in a dental clinic of a specialization program in Orthodontics. METHODS: Data were collected from the records of patients treated from 1997 to 2015. Potential predictors for treatment conclusion were investigated: patient-related factors (PRFs) and treatment-related factors (TRFs). PRFs were sex, age, face balance, Angle malocclusion classification, open bite, denture, facial pattern, facial profile, buccal corridor, crossbite, maxillary deficiency, and sagittal mandibular behavior; and TRFs were therapeutic approaches, treatment modality, extractions, and Bolton discrepancy. The initial and final treatment dates were collected. Descriptive data analysis, univariate, and multivariate logistic regression were performed (5% significance). RESULTS: Of the 903 records, 561 patients were included in the study. It was demonstrated that starting the treatment at a young age (PRF) and the presence of crossbite (TRF) are predictive factors for the treatment conclusion. A vertical facial pattern (dolichofacial or brachyfacial) and a greater number of extractions for orthodontic reasons may contribute positively to the conclusion of the treatment. The frequency of treatment inconclusion was higher during the first 2 years of treatment (more than 50% of the patients that initiated the treatment). CONCLUSIONS: Young age at the beginning of treatment and the presence of crossbite malocclusion can increase the chance of treatment conclusion.

Treatment of maxillary canine transposition.

Transposition of maxillary teeth is an eruptive disturbance occurring in approximately 1 of every 300 orthodontic patients. Such cases are frequently very challenging in terms of treatment planning and orthodontic management. The canine is one of the most commonly transposed teeth, ectopically positioned with either the lateral incisor or the first premolar. This case report illustrates unique orthodontic treatment, describes treatment procedures, and presents the final outcome of bilateral maxillary canine-lateral incisor complete transpositions in which the involved teeth were moved to their clinically normal position in the dental arch without extracting premolars.

An in vitro assessment of the influences of different wire materials and bracket systems when correcting dental crowding.

A recently developed orthodontic wire alloy known as GUMMETAL® is claimed to deliver more physiological forces to correct dental mispositioning. However, its mechanical characteristics have not been fully characterized yet. This study aimed to determine and compare the elastic properties of different wire alloys, such as nickel-titanium (NiTi), stainless steel (SS), and GUMMETAL®, and assess their unloading forces when combined with either conventional or self-ligating brackets (CL and SL) when correcting dental crowding. All wires had a 0.016″ cross-section diameter. A three-point bending test was performed to assess the maximum deflection of each wire. Then, a subsequent analysis measured the unloading force for each wire/bracket system in a dental crowding clinical simulation device. The test was carried out in a universal testing machine with a cross-speed displacement of 0.5 mm/min. Data were recorded in different ranges and statistically evaluated using two-way analysis of variance. GUMMETAL® displayed higher unloading mean forces in SL brackets (2228.78 cN) than CL brackets (1967.38 cN) for the 1.6-3.0 deflection interval (p = 0.018). Within this interval, NiTi showed higher forces when used with CL brackets (2683.06 cN) than with SL brackets (1179.66 cN) (p < 0.0001). For the CL bracket systems, SS wires showed higher forces (2125.31 cN) in the 1.0-1.6 deflection interval than the other two wire alloys (NiTi, 1541.52 cN and GUMMETAL®, 852.65 cN) (p < 0.0001). SS wires also displayed lower forces with SL brackets (1844.01 cN) than in CL brackets (2125.31 cN) (p = 0.049). Thus, only GUMMETAL® revealed to be an optimal choice for SL brackets, whereas NiTi for CL brackets.

Análisis de flexión en alambres de níquel-titanio con y sin propiedades de transformación térmica / Bending analysis of nickel-titanium wires with and no thermal transformation properties

Objetivo: Evaluar el comportamiento de los alambres de aleación de níquel-titanio con y sin propiedades de transformación térmica en la relación carga/deflexión. Materiales y método: Para ello, 30 segmentos de alambres de níquel-titanio con calibre .014" y 30 mm de largo fueron cortados, conformando 10 segmentos de alambre Flexy NiTi de Orthometric®, 10 segmentos Flexy Copper NiTi termoactivado y 10 segmentos CuNiTi de OrmcoTM. Se usó una máquina universal de ensayos Instron® para analizar el comportamiento de carga y deflexión de los segmentos en una prueba de tres puntos, registrando las fuerzas alcanzadas en 0,5 mm: 1 mm, 2 mm y 4 mm de deflexión. Resultados: Hubo una diferencia estadísticamente significativa entre todos los alambres y entre todas las deflexiones, ya que el alambre Flexy Cooper NiTi presentó la menor carga entre todas las deflexiones analizadas. Conclusión: Se concluye que los alambres termoactivados alcanzan fuerzas más leves, lo que los hace más apropiados para alineaciones iniciales, las cuales requieren un mayor rango de deflexión(AU)

Elásticos intermaxilares e bráquetes autoligáveis passivos no tratamento da Classe II dentoalveolar: uma relação sinérgica / Intermaxillary elastics and passive self-ligating brackets in the treatment of dentoalveolar Class II: a synergistic relationship

A má oclusão de Classe II caracteriza-se por um desequilíbrio no sentido anteroposterior dos arcos dentários. Essa discrepância maxilomandibular desencadeia problemas estéticos e funcionais, justificando o grande número de pacientes que apresentam essa má oclusão nos consultórios de todo o mundo. Este caso clínico apresenta o tratamento ortodôntico compensatório de um paciente em crescimento, portador de má oclusão de Classe II com retrognatismo mandibular e sobremordida aumentada. Elásticos intermaxilares de Classe II foram utilizados na mecânica com bráquetes do sistema autoligável Damon para a correção sagital. Os resultados do tratamento mostraram uma melhora no corredor bucal dada pelos torques adequados dos dentes posteriores, manutenção dos planos verticais e crescimento facial significativo durante o período do tratamento ortodôntico. No aspecto dentário, foram corrigidas as inclinações vestíbulo-linguais dos incisivos superiores e os incisivos inferiores mantiveram sua posição inicial. (AU)

Class II malocclusion is presented by an imbalance in the anteroposterior relationship of dental arches. This maxillomandibular discrepancy causes aesthetic and functional problems, justifying the large number of patients who present this malocclusion in clinics around the world. This clinical case presents the compensatory orthodontic treatment of a Class II growing patient with retrognathism and increased overbite. Class II intermaxillary elastics were used in the mechanics with Damon system passive self-ligating brackets for sagittal correction. The results showed an improvement in the oral corridor due to adequate torques of the posterior teeth, maintenance of the vertical planes and significant facial growth during the orthodontic treatment. In dental aspect, buccolingual inclinations of upper incisors were corrected and the lower incisors maintained their initial position. (AU)

Proteoglycans and dental biology: the first review.

Proteoglycans (PGs) are proteins which are vital components located in the extracellular matrix, cell surface or intracellular granules. They are linked to polysaccharides called glycosaminoglycans. There are several aspects associated with PGs, such as cell signaling and organization of the extracellular matrix (ECM), making them pivotal participants in many tissue compositions. In teeth, PGs also play an essential role, as many of its components have elaborate ECM structures. However, lack of information on how PGs constitute the various tissues of the tooth and on their roles makes it difficult to elicit the major importance associated with this class of proteins. This review seeks to detail how proteoglycans are involved in many aspects of tooth organization and development, and as far as we are concerned, this has not been performed yet. We have also exemplified the participation of small leucine-rich proteoglycans, a special class of PGs seen in dental trauma cases.

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.

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.

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

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.

Evaluation of Damon system effects in alveolar bone support by cone-beam computed tomography (CBCT) / Avaliação dos efeitos do sistema Damon no suporte ósseo dentário por meio da tomografia computadorizada de feixe cônico (TCFC)

Introduction: The aim of this study was to assess changes in buccal bone thickness, buccolingual inclinations and transversal width of teeth during treatment with the Damon System. Material and Methods: Twenty-one patients of both sexes, with a mean initial age of 14.99 ± 1.27 years, with complete permanent dentition up to second molars, treated with no extractions and minimum initial crowding of 4mm (maxillary: - 6.71mm (SD 2.99), mandibular: -5.12 mm (SD 2.03)) were taken to CBCT scan before (T1) and after (T2) orthodontic treatment with the Damon System. In the maxilla, buccal bone thickness was measured at 4mm and 6mm from the cementoenamel junction of the right first molar in the apical direction. For the mandible, the same protocol was used, but the axial sections were performed at 4mm and 8mm. Buccolingual inclinations were verified using CBCT-panoramic cross-sectionals based on the image that presented the most appropriate view of buccal face of the clinical crown. Transversal width measurements were performed in intermolar, intersecond premolar, interfirst premolar and intercanine distances by 3D multiplanar reconstruction in the two-time periods. Distribution of the variables was verified by Shapiro-Wilk test. Changes in all variables from T1 to T2 were compared using paired t-test. The correlation between changes in bone thickness, buccolingual inclinations and transversal width was assessed by Pearson correlation coefficient. Results: At 4mm height, treatment with Damon System produced a statistically significant decrease in buccal bone thickness, mainly in the posterior teeth of the maxillary and mandibular arches. At 8mm, there was a statistically significant decrease in buccal bone thickness only in mandibular molar and premolar teeth. Regarding buccolingual inclinations, a statistically significant increase was observed in the maxillary arch, mainly in the incisors and premolars teeth. In the mandibular arch, all teeth showed a statistically significant increase of buccal inclination, except for the left canine and first molar. Concerning transversal width, there was a statistically significant increase in maxillary and mandibular transversal width at the end of treatment, exception of the maxillary canines. Conclusion: In general, orthodontic treatment with the Damon self-ligating brackets system showed an expansion of the dental arches followed by a decrease in buccal bone thickness, caused by buccal inclination of dental crowns in both arches.(AU)

Introdução: O objetivo do presente estudo foi avaliar as alterações nas espessuras das tábuas ósseas vestibulares, nas inclinações dentárias e nas dimensões transversais dos arcos durante o tratamento com o Sistema Damon de braquetes autoligáveis. Materiais e Métodos: Vinte e um adolescentes de ambos os gêneros com idade média de 14,99 ± 1,27 anos, dentadura permanente completa até os segundos molares, tratados sem extrações e apinhamento inicial mínimo de 4mm (superior: -6,71mm (DP 2,99), inferior: -5,12mm (DP 2,03) foram submetidos a exames de Tomografia Computadorizada de Feixe Cônico (TCFC) antes (T1) e após (T2) o tratamento ortodôntico com o Sistema Damon. A espessura da tábua óssea vestibular da maxila foi determinada por cortes axiais nas distâncias de 4mm e 6mm localizados apicalmente à junção amelocementária do primeiro molar superior direito. Para a mandíbula, foi realizado o mesmo protocolo, porém os cortes axiais selecionados foram realizados nas distâncias de 4mm e 8mm apicalmente à junção amelocementária do primeiro molar inferior direito. Para mensuração das inclinações dentárias, foram utilizados cortes parassagitais gerados a partir da imagem panorâmica da TCFC. As medidas foram realizadas a partir do ângulo formado pela linha vestibular da coroa clínica (LVCC) e a borda superior ou inferior da imagem selecionada. As dimensões transversais dos arcos (6-6/5-5/4-4/3-3) foram mensuradas por meio de cortes axiais das reconstruções 3D. As variáveis foram submetidas ao teste de Shapiro-Wilk para testar sua distribuição. As alterações de todas as variáveis de T1 para T2 foram comparadas por meio dos testes t-pareado. A correlação entre as alterações das espessuras ósseas com as alterações nas inclinações dentárias e dimensões transversais dos arcos foi verificada pelo coeficiente de correlação de Pearson. Resultados: o tratamento com o Sistema Damon produziu uma diminuição estatisticamente significante na espessura da tábua óssea vestibular predominantemente na região posterior dos arcos superior e inferior no corte realizado a 4mm. Nos cortes realizados a 8mm, houve uma diminuição estatisticamente significante na espessura óssea vestibular somente na região de molares e premolares inferiores. Em relação as inclinações vestibulolinguais dos dentes, um aumento estatisticamente significante foi observado no arco superior, com predomínio nos incisivos e premolares. No arco inferior, todos os dentes mostraram um aumento estatisticamente significante da inclinação para vestibular, com exceção do canino e primeiro molar esquerdos. As dimensões transversais dos arcos superiores e inferiores sofreram um aumento estatisticamente significante ao final do tratamento com o Sistema Damon, com exceção dos caninos superiores. Conclusão: De maneira geral, o tratamento ortodôntico com o Sistema Damon de braquetes autoligáveis produziu um aumento nas dimensões transversais seguida por uma redução da espessura óssea na parede vestibular dos dentes, ocasionada pela inclinação vestibular das coroas dentárias em ambos os arcos.(AU)

Opções de tratamento ortodôntico compensatório da classe III sem exodontias de premolares / Treatment options of compensatory orthodontic treatment without premolar extractions

O tratamento ortodôntico, em pacientes adultos com padrão esquelético apresentando pequena discrepância, pode ser realizado com a camuflagem ortodôntica, por meio das compensações dentárias. Essas compensações, muitas vezes, são consideradas como fatores de risco para a saúde periodontal, principalmente, quando associadas à movimentos de inclinação dos incisivos, tanto para lingual como para vestibular. A finalidade do presente artigo foi apresentar, através de dois de casos clínicos, duas opções diferentes de tratamento compensatório para a Classe III. A primeira com o emprego de bráquetes autoligáveis do Sistema Damon, com prescrição individualizada para os arcos dentários superior e inferior, além dos elásticos intermaxilares de Classe III. Essa modalidade tem sua indicação na correção dos problemas dentários com suave discrepância esquelética entre as bases ósseas, corrigindo os problemas oclusais sem grandes sequelas para os dentes e tecidos de suporte, devido ao torque diferenciado dos bráquetes. A segunda opção é a movimentação sagital dos dentes inferiores para distal por meio de ancoragem esquelética com miniplacas de titânio. Esses dispositivos de ancoragem temporária (DATs) oferecem uma estável e efetiva ancoragem para a movimentação ortodôntica no tratamento da Classe III.(AU)

Orthodontic treatment, in adult patients with a skeletal pattern presenting a small discrepancy, can be performed with orthodontic camouflage by dental compensations. These compensations are many times considered as risk factors for periodontal health, especially when associated with incisor inclination, both lingual and buccal. The aim of this paper was to present, through two clinical cases, two different options for compensatory Class III treatment. The first one with the use of self-ligating brackets (Damon System), with individualized prescriptions for upper and lower dental arches, in addition to Class III intermaxillary elastics. This modality has its indication in the correction of dental problems with mild skeletal discrepancy between bone bases, correcting the occlusal problems without major sequelae for teeth and supporting tissues, due to brackets different torque. The second option is retracting the whole lower dentition through skeletal anchorage with titanium miniplates. These temporary anchoring devices (TADs) provide a stable and effective anchorage for orthodontic movement in Class III treatment.(AU)

External root resorption with the self-ligating Damon system-a retrospective study.

BACKGROUND: The aim of this study was to compare the degree of external apical root resorption (EARR) in patients treated with self-ligating Damon appliances and with conventional preadjusted appliances. METHODS: The sample comprised 52 patients, divided into two groups. Group 1 consisted of 25 patients treated with self-ligating Damon appliances, with an initial age of 16.04 years, final age of 18.06 years, and treatment time of 2.02 years. Group 2 consisted of 27 patients, treated with conventional preadjusted appliances, with an initial age of 16.77 years, final age of 18.47 years and treatment time of 1.70 years. The groups were matched regarding the initial and final ages, treatment time, type of malocclusion, and treatment protocol without extractions. Root resorption was evaluated on periapical radiographs of the maxillary and mandibular incisors at the end of orthodontic treatment with the scores of Levander and Malmgren. Intergroup comparisons of root resorption were performed with Mann-Whitney tests. RESULTS: No significant difference in the degree of root resorption between the two groups was found. CONCLUSIONS: Similar degrees of resorption can be expected after non-extraction treatment with Damon self-ligating or conventional preadjusted appliances.

Bráquetes autoligáveis / Self-ligating brackets

Os bráquetes autoligáveis tornaram-se populares recentemente no mercado ortodôntico com diversos atrativos, incluindo um modo de ligação mais rápida, menor atrito, menor dor e maior conforto ao paciente, menor número de atendimentos e menor tempo de cadeira. Embora diversos tipos de bráquetes autoligáveis tenham estado disponíveis por diversos anos, só recentemente cresceram novamente em popularidade. O objetivo deste trabalho é revisar a literatura sobre o assunto, elucidando as vantagens da utilização desses bráquetes, os efeitos dos mesmos sobre a forma do arco, inclinação dos incisivos e as diferenças com relação aos torques.

Self-ligating brackets have become popular recently in the orthodontic market with many attractions including a faster ligation, less friction, less pain and greater patient comfort, fewer appointments and shorter chair time. Although several types of self-ligating brackets have been available for several years, only recently they have grown in popularity again. The objective of this work is to review the literature on the subject, explaining the advantages of using these brackets, their effects on arch form, inclination of incisors and differences related to torques.