Tratamento de má oclusão de Classe II por meio de distalização sequencial posterior com alinhadores ortodônticos ClearCorrect / Treatment of Class II malocclusion through upper distalization with ClearCorrect aligners

Resumo A segunda mais prevalente má oclusão de Angle na população é a de Classe II. Dentre as abordagens de tratamento consideradas pelos profissionais, está a distalização dos dentes posteriores superiores ou exodontias. A distalização, dependendo do nível de complexidade do caso, pode ser desafiadora e necessitar de mecânicas auxiliares para realizar movimentos translacionais e não somente de inclinação coronária. A escolha da abordagem para esses tratamentos depende diretamente da colaboração do paciente, severidade da má oclusão, caracterização da Classe II, idade do paciente e habilidade técnica do profissional responsável. Com o aumento da procura por tratamentos ortodônticos mais estéticos, os alinhadores ortodônticos têm sido frequentemente uma alternativa aos pacientes. Dependendo da severidade da má oclusão, pode-se associar aos auxiliares comumente utilizados na Ortodontia convencional fixa. Portanto, o objetivo deste trabalho é apresentar a resolução de uma má oclusão de Classe II, divisão 1, com impactação do canino superior direito e desvio de linha média superior para a direita tratada com alinhadores ortodônticos ClearCorrect. (AU)

Abstract The second more prevalent Angle's malocclusion on the population is Class II. Among the continuously considered treatment approaches by clinicians, is the distalization of upper teeth or extractions. The distalizations, depending on the case's complexity, can be challenging and need auxiliary mechanics to perform translation movements and not just crown tipping. The choose of the appliance for these treatments relies directly on the option/collaboration of the patient, malocclusion severeness, patient's age, and technical ability of the main professional taking care of the case. With the crescent search for more aesthetic orthodontic treatments, the clear aligners have been frequently looked for by the patients as an alternative and, regularly related to auxiliaries commonly associated to the conventional fixed appliances. Regarding this context, the objective of this study is to present the case report of a patient with Class II, division 1, upper midline deviation to the right and unerupted upper right canine through the ClearCorrect aligners' system. (AU)

Abordagem precoce da má oclusão de Classe II esquelética com atresia maxilar e mordida aberta anterior e o uso de alinhadores ClearCorrect ­ relato de caso / Early approach to skeletal Class II malocclusion with maxillary atresia and anterior open bite and the use of ClearCorrect aligners ­ case report

Resumo O adequado planejamento e o tratamento precoce da má oclusão de Classe II de Angle, com atresia maxilar e mordida aberta anterior, proporciona a harmonização das bases ósseas maxilo-mandibulares nos três planos do espaço. Os alinhadores ortodônticos surgiram como uma alternativa de tratamento, tendo como vantagens: serem mais estéticos e mais confortáveis para o paciente, permitirem menor tempo de tratamento, quando corretamente indicados, menor tempo de cadeira, menos intercorrências, possibilidade de monitoramento à distância, maior facilidade de alimentação e higienização dentária. Por outro lado, apresentam dificuldades em tratamentos de adultos com más oclusões severas de Classe II esquelética, de mordida cruzada posterior e de mordida aberta anterior. Portanto se objetiva com esse relato de caso clínico corrigir precocemente a má oclusão de Classe II esquelética com atresia maxilar, por meio do uso de ortopedia mecânica e dispositivos que auxiliam na eliminação de hábitos e fechamento da mordida aberta anterior e, posteriormente, a utilização de alinhadores ortodônticos para a finalização do tratamento. Concluiu-se que o tratamento interceptativo precoce da má oclusão foi eficiente para a harmonização entre as bases ósseas nos sentidos ântero-posterior, vertical e transversal, transformando essa má oclusão de alta para baixa complexidade e, consequentemente, altamente previsível e com excelente prognóstico para o tratamento com alinhadores ortodônticos. O tratamento com os alinhadores ClearCorrect corrigiu a oclusão em um curto período de tempo, quando comparado com Ortodontia corretiva e com uma alta previsibilidade em relação ao setup virtual. (AU)

Abstract Adequate planning and early treatment of Angle Class II malocclusion with maxillary atresia and anterior open bite provides harmonization of maxillomandibular bone bases in the three planes of space. Orthodontic aligners have emerged as an alternative treatment having the following advantages: being more aesthetic and more comfortable for the patient, less treatment time when they are correctly indicated, less chairside time, less complications, possibility of remote monitoring, easier feeding, and dental hygiene. On the other hand, they offer difficulties to treat adults with severe skeletal Class II malocclusions, posterior crossbite and anterior open bite. Therefore, the objective of this clinical case report is to early correct skeletal Class II malocclusion with maxillary atresia through the use of mechanical orthopedics and devices that help eliminate habits and close the anterior open bite, and later the use of orthodontic aligners to finish the treatment. It was concluded that the early interceptive treatment of malocclusion was efficient to harmonize the bone bases in the anteroposterior, vertical, and transversal directions, changing this malocclusion from high to low complexity and, consequently, highly predictable and with an excellent prognosis for treatment with orthodontic aligners. The treatment with ClearCorrect aligners corrected the occlusion in a shorter period of time when compared to corrective orthodontics and with a high (AU)

Tratamento da má oclusão de Classe II/2 com alinhadores ClearCorrect ­ relato de caso / Class II/2 maloclusion treatment with ClearCorrect aligners ­ case report

Resumo O objetivo deste trabalho foi abordar o planejamento e o tratamento de uma má oclusão de Classe II/2 tratada sem extrações, utilizando alinhadores transparentes. No tratamento dessa má oclusão é necessário considerar o grau de severidade, se é dentária ou esquelética (avaliar se acomete somente a maxila, somente a mandíbula ou ambas), se há ou não crescimento, a colaboração do paciente, dentre outros fatores. Atualmente, muitos pacientes que procuram o tratamento ortodôntico desejam utilizar aparelhos mais estéticos, principalmente aqueles que já utilizaram o aparelho fixo convencional. Dessa forma houve um grande incremento na demanda pelos alinhadores transparentes removíveis, proporcionando benefícios como estética, maior facilidade de higienização e menor tempo de tratamento. No presente caso clínico, procurou-se manter o bom relacionamento maxilo-mandibular, o perfil e o bom selamento labial. Para tanto foram utilizados os alinhadores da ClearCorrect®, optou-se por não extrair pré-molar e realizar a distalização sequencial do lado da má oclusão de Classe II, associando com elásticos intermaxilares de Classe II, desgastes interproximais (IPR) e attachments. Os resultados alcançados foram altamente satisfatórios, restabelecendo o bom engrenamento dos molares e caninos, as inclinações vestíbulo-linguais adequadas dos incisivos superiores e inferiores, o overjet, o overbite e a correção das linhas médias. Portanto se concluiu que o tratamento desse caso clínico com alinhadores foi relativamente rápido, tão eficiente quanto o tratamento com aparelho fixo convencional e atendeu às expectativas estéticas da paciente. (AU)

Abstract The aim of this research was to address the planning and treatment of a Class II/2 malocclusion treated without extractions, using orthodontic clear aligners. For this malocclusion treatment it is necessary to consider the severity degree, whether it is dental or skeletal (assess whether it affects only maxilla, mandible, or both), whether there is growth or not, patient collaboration, among other factors. Currently, many patients that search for orthodontic treatment seek more aesthetic appliances, mainly those who have already used the conventional fixed appliance. Thus, there was a great increase in the demand for removable clear aligners, since they provide benefits such as aesthetics, easier hygiene and shorter treatment time. In this case report, we tried to maintain good maxillomandibular relationship, the profile and good lip sealing. To do so, ClearCorrect® aligners were used, also it was chosen not to extract premolars and to perform a sequential distalization on the Class II malocclusion side, associated with Class II intermaxillary elastics, stripping (IPR) and atttachments. The results were highly satisfactory, restoring good molars and canines relationship, adequate upper and lower incisors buccolingual inclinations, overjet, overbite and middle line correction. Therefore, it was concluded that the treatment of this case with clear aligners was relatively quick, as efficient as the treatment with a conventional fixed appliance and met the patient's aesthetic expectations. (AU)

Bone response after immediate placement of implants in the anterior maxilla: a systematic review.

PURPOSE: The objective of this systematic review was to assess the three-dimensional changes in bone tissue after immediate installation of a single implant in a fresh extraction socket in the anterior maxilla. METHODS: After defining a strategy, an electronic search was carried out using the databases PubMed, Embase, LILACS, Web of Science, Cochrane, and Scopus. In addition, the gray literature was also researched using Google Scholar and ProQuest. Two reviewers independently screened for eligible studies, assessed the methodological quality, and extracted the data. The inclusion criteria were observational studies and experimental studies that assessed bone response after the immediate installation of a single implant in a fresh extraction socket, immediately loaded or not, in the region between the maxillary canines. Studies were included in any language, with no publication date restrictions and with a minimum of 6 months of follow-up after the surgical procedure. RESULTS: From a total of 3272 articles, only 12 studies met the inclusion criteria and were selected for the review. Bone remodeling after immediate installation of a dental implant was assessed using standardized periapical radiographs and cone beam computed tomography (CBCT). CONCLUSION: It can be concluded that bone remodeling occurs after tooth extraction and immediate implant installation.

Avaliação da percepção e da satisfação estética de pacientes que foram tratados com toxina botulínica tipo A para correção do sorriso gengival / Assessment of patients' perception and satisfaction with the botulinum toxin type A treatment for gummy smile

O sorriso gengival é caracterizado pela exposição excessiva da gengiva ao sorrir. Esta alteração pode ser classificada em anterior, posterior, mista e assimétrica. Sua etiologia está associada a diversos fatores, tais como gengivais, esqueléticos e musculares. A toxina botulínica tipo A tem sido bastante utilizada na Odontologia para a correção do sorriso gengival, tendo como vantagem ser um procedimento pouco invasivo, seguro e eficaz. Esta pesquisa teve como objetivo avaliar, por meio de questionários, a satisfação dos pacientes em relação aos resultados obtidos com a aplicação da toxina botulínica tipo A para a correção do sorriso gengival. O questionário foi respondido antes da aplicação da toxina e 15 dias após. Participaram da pesquisa um total de 15 pacientes. Os resultados obtidos indicaram que os participantes classificaram seus sorrisos, após a aplicação da toxina botulínica, como muito bom e excelente. Todos os participantes da pesquisa relataram que ao sorrir não apresentavam exposição gengival e sentiam-se confortáveis durante o sorriso após a aplicação da toxina. Portanto, concluiu-se que os participantes da presente pesquisa apresentaram alto grau de satisfação com os resultados obtidos no tratamento do sorriso gengival com a aplicação da toxina botulínica tipo A (AU).

Gummy smile is characterized by gingival tissue excessive exposure while smiling. It can be classified as anterior, posterior, mixed, and asymmetric. Its etiology is associated with several factors, such as gingival, skeletal, and muscular. Botulinum toxin type A has been widely used in Dentistry for gingival smile correction with the advantage of being a less invasive, safe, and effective procedure. The purpose of this study was to investigate patient satisfaction in relation to the results obtained with botulinum toxin type A application for gummy smile correction using questionnaires. The questionnaire was answered before and after 15 days of the toxin application. A group of 15 patients participated of the study. The results showed that the participants classified their smiles, after the application of botulinum toxin, as very good and excellent. All study participants reported no more discomfort with gingival exposure when smiling and everyone felt comfortable with the smile after botulinum toxin application. Therefore, it was concluded that all participants were satisfied with the results obtained after botulinum toxin type A gummy smile treatment (AU).

Comparative Analysis of Cutting Efficiency and Surface Maintenance Between Different Types of Implant Drills: An In Vitro Study.

INTRODUCTION: This study evaluated cutting efficiency (CE) and linear wear of dental implant drills after 450 standardized osteotomies on bovine ribs. Diamond-like carbon-coated steel drills (SG), acid-treated steel drills (EG), and ceramic drills (ZG) were divided into 6 subgroups according to the number of uses. MATERIALS AND METHODS: A robot-controlled program performed systematic instrumentation, timing, axial loading, and managed feed rate. CE was recorded in a polyurethane resin blank and end wear (VBBmax) was analyzed under stereo microscopy. RESULTS: After osteotomies in beef ribs, CE for the Ø2.0-mm drill decreased 10.2% in SG and 10.9% in ZG; for the Ø3.0-mm drill, CE decreased 30.6% in SG, 8.5% in ZG, and improved in EG. The greatest wear occurred in Ø2.0-mm drills; ZG drills (Ø3.0 mm) exhibited only edge frittering, as confirmed on scanning electron microscopy. CONCLUSION: After 50 exposures to mechanical loads, steel and ceramic drills lost CE. Whereas cutting and thermal performance improved in experimental drills, the Ø2.0-mm drill exhibited the most signs of wear proportional to use. These findings suggest that, with the methodology employed, the life of these drills exceeds 50 osteotomies.

Thermal Variation During Osteotomy With Different Dental Implant Drills: A Standardized Study in Bovine Ribs.

INTRODUCTION: This study evaluated thermal variation (heat generation) by dental drills of similar geometries, made from different materials, during performance of 450 standardized osteotomies in bovine ribs to simulate implant site preparations. MATERIALS AND METHODS: Each of the 3 groups-steel with a diamond-like carbon coating (SG), experimentally surface-treated steel (EG), and aluminum-toughened zirconium ceramic (ZG)-included 3 drills, distributed across 6 subgroups. An implant motor provided torque, rotation, and irrigation for 50% of subgroups. RESULTS: In preparations drilled to 5 mm under irrigation, the number of osteotomies, material, and diameter did not influence thermal variation (ΔT); when drilling to 13 mm, the greatest ΔT occurred in EG (2.8°C). When drilling to 5 mm without irrigation, drill material influenced mean temperature; when drilling to 13 mm without irrigation, the greatest ΔT (5.5°C) occurred in EG. The highest temperature was observed in SG (79.6°C). CONCLUSION: After 50 uses, the greatest ΔT occurred in EG and the ∅3.0-mm drill exhibited the highest mean and peak temperatures. Temperatures were influenced by irrigation, number of uses, depth, drill diameter, geometry, and material; however, mean values were within physiological limits.

Gingival condition associated with two types of orthodontic fixed retainers: a meta-analysis.

BACKGROUND: The maintenance of gingival health around orthodontic fixed retainers (FRs) is difficult and different designs have been proposed. OBJECTIVE: The goal of this systematic review was to analyse whether FR designs that allow unobstructed interproximal flossing, compared with the ones that do not, improve gingival parameters. SEARCH METHODS: Detailed individual database search strategies for Cochrane Library, 'Latin' American and 'Caribbean' Health Sciences Literature, PubMed, Scopus, and Web of Science were developed. Grey literature was also considered. SELECTION CRITERIA: Clinical trials and cross-sectional studies that compared two types of FRs (plain and waved) were included and evaluated. DATA COLLECTION AND ANALYSIS: Study selection, data extraction, and risk of bias (RoB) assessment were performed individually and in duplicate. The methodology quality was assessed using the MAStARI RoB tool. RESULTS: Four studies met the inclusion criteria, and all presented moderate RoB. While two of those studies found a statistically significant difference in gingival parameters, the other two did not report differences. A meta-analysis was conducted based on two of the selected studies, which performed evaluations of plaque index (PI) and calculus index (CI). The results revealed no differences on PI between wave FR and plain FR of 0.46 (0.24 to 0.69) and no differences on CI of 0.12 (-0.10 to 0.33). Regarding comfort, no clear differences were identified. CONCLUSIONS: There is not enough scientific evidence to support or not an association between FR design and gingival health, flossing frequency, or patient comfort. REGISTRATION: PROSPERO - CRD42016030059.

Expansão rápida da maxila osseossuportada: um relato de caso e passo a passo laboratorial / Rapid bone-borne maxillary expansion: a case report and laboratorial step-by-step

A expansão rápida da maxila osseossuportada tem sido amplamente utilizada na clínica ortodôntica, entretanto ainda existem dúvidas em relação ao planejamento e efeitos do tratamento. É objetivo do presente artigo relatar um caso clínico descrevendo passo a passo as etapas de planejamento, confecção e instalação do aparelho. Paciente com mordida cruzada posterior, 11 anos de idade foi indicada para tratamento com aparelho. Inicialmente, foi realizada tomografia computadorizada de feixe cônico a fim de planejar o local ideal de instalação de 4 mini-implantes considerando a disponibilidade óssea no palato. Imediatamente após a instalação dos mini-implantes foi realizada moldagem, adaptação de mini-implantes de latão no alginato e confeccionado modelo de trabalho. O disjuntor em acrílico, apoiado apenas nos mini-implantes, foi adaptado em boca e a paciente instruída a ativar o torno expansor » de volta pela manhã e a noite durante 14 dias. Após esse período nova tomografia foi realizada, assim como após o tempo de contenção de 4 meses. Mensurações nas tomografias mostraram expansão maxilar sem efeitos de vestibularização de molares. Após 4 meses foi observada leve redução da expansão esquelética e inclinação lingual dos dentes posteriores. Pode ser concluído que o tratamento foi bem sucedido, resultando em correção da mordida cruzada posterior sem efeitos colaterais nos dentes posteriores.(AU)

Rapid bone-borne maxillary expansion has been widely used in orthodontic clinic, however there are still some doubts about its planning and treatment effects. The aim of this paper is to report a case describing step-by-step planning, manufacturing and installation of the appliance. Patient with posterior crossbite, 11 years-old was indicated to treatment with this appliance. A cone bean computed tomography was achieved to plan the ideal site for installing 4 miniscrews, considering bone availability of the palatal area. Immediately after miniscrews insertion, an impression was taken and miniscrews were inserted in the alginate to obtain the cast model. The acrylic appliance, supported exclusively on miniscrews, was adapted and the patient instructed to activate » turn twice a day for 14 days. After this period a new tomography was obtained and also after a 4-month retention period. Tomography measurements showed maxillary expansion with no molars vestibularization. After 4 months there was a slight decrease on maxillary expansion and molars lingual tipping. It can be concluded that the treatment was successful with correction of the crossbite and no deleterious effects in the posterior teeth.(AU)

Assessing the effects of hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets.

BACKGROUND: Tooth bleaching is, today, one of the most widespread cosmetic treatments in dental practice,  so it is important to determine whether it can interfere with orthodontic bonding or not. AIM: The aim of this study was to assess the in vitro effects of 35% hydrogen peroxide bleaching agent on the shear bond strength of orthodontic brackets. MATERIALS AND METHODS: Forty-five upper bicuspids were divided into three groups (n = 15). In the control Group (C), the brackets were bonded without previous bleaching treatment. Group 1 (G1) was treated with 35% hydrogen peroxide bleaching agent 24 h before bracket bonding. Group 2 was also bleached, and the brackets were bonded after 30 days. The shear bond strength of the brackets was measured using an EMIC machine, and the results were analyzed by ANOVA. RESULTS: There were no statistically significant differences between the three groups (P > 0.05), with Group C showing a mean bond strength of 9.72 ± 2.63 MPa, G1 of 8.09 ± 2.63 MPa, and G2 of 11.15 ± 4.42 MPa. CONCLUSION: It was possible to conclude that 35% hydrogen peroxide bleaching agent does not affect the shear strength of orthodontic brackets bonded 24 h and 30 days after bleaching.

Estudo comparativo entre dois diferentes métodos de ancoragem esquelética para intrusão de molares superiores / Comparative study of two different methods of skeletal anchorage for upper molar intrusion

O objetivo deste trabalho foi comparar a efetividade de dois dispositivos de ancoragem ortodôntica, nos movimentos de intrusão de molares superiores. Neste estudo clínico prospectivo, 12 indivíduos que necessitavam de intrusão de molares superiores receberam miniplacas e mini-implantes para proporcionar ancoragem esquelética temporária. Observaram-se os aspectos clínicos e os sintomas pós-operatórios, bem como a efetividade dos métodos. Houve a perda de uma miniplaca por infecção e de mini-implantes palatinos, por falta de higiene local. Os dois tipos de dispositivos de ancoragem se mostraram capazes de auxiliar o movimento ortodôntico de intrusão sem causar nenhum tipo de prejuízo aos pacientes.

The aim of this study was to compare the effectiveness of two orthodontic anchorage devices for upper molar intrusion. In this prospective clinical study, 12 subjects received miniplates and mini-implants to provide temporary skeletal anchorage. Clinical and postoperative symptoms were observed as well as the effectiveness of both methods. One miniplate and palatal mini-implants were lost due to lack of local hygiene. Both types of anchoring devices can help orthodontic intrusion movement without patient compromising.

Differences in the force system delivered by different beta-titanium wires in elaborate designs.

OBJECTIVE: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. METHODS: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. RESULTS: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. CONCLUSION: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends.

Differences in the force system delivered by different beta-titanium wires in elaborate designs

Abstract Objective: Evaluation of the force system produced by four brands of b-Ti wires bent into an elaborate design. Methods: A total of 40 T-loop springs (TLS) hand-bent from 0.017 x 0.025-in b-Ti were randomly divided into four groups according to wire brand: TMATM(G1), BETA FLEXYTM (G2), BETA III WIRETM (G3) and BETA CNATM (G4). Forces and moments were recorded by a moment transducer, coupled to a digital extensometer indicator adapted to a testing machine, every 0.5 mm of deactivation from 5 mm of the initial activation. The moment-to-force (MF) ratio, the overlapping of the vertical extensions of the TLSs and the load-deflection (LD) ratio were also calculated. To complement the results, the Young's module (YM) of each wire was determined by the slope of the load-deflection graph of a tensile test. The surface chemical composition was also evaluated by an energy dispersive X-ray fluorescence spectrometer. Results: All groups, except for G2, produced similar force levels initially. G3 produced the highest LD rates and G1 and G4 had similar amounts of overlap of the vertical extensions of the TLSs in "neutral position". G1 and G3 delivered the highest levels of moments, and G2 and G3 produced the highest MF ratios. b-Ti wires from G3 produced the highest YM and all groups showed similar composition, except for G2. Conclusion: The four beta-titanium wires analyzed produced different force systems when used in a more elaborate design due to the fact that each wire responds differently to bends.

Resumo Objetivo: avaliar os sistemas de força produzidos por quatro marcas de fios de -Ti, dobrados em formas complexas. Métodos: quarenta molas T-Loop (TLS) dobradas à mão, confeccionadas a partir de fios de -Ti, calibre 0,017" x 0,025", foram aleatoriamente divididas em quatro grupos, de acordo com a marca do fio: TMA (G1), BETA FLEXY (G2), BETA III Wire (G3) e BETA CNA (G4). Forças e momentos foram registrados por um transdutor de momento - acoplado a um extensômetro digital, adaptado a uma máquina de ensaios -, a cada 0,5mm de desativação, a partir de 5mm da ativação inicial. A proporção momento-força (M/F), a sobreposição das extensões verticais das TLSs e a relação carga-deflexão (C/D) também foram calculadas. Para completar os resultados, o módulo de Young (MY) de cada fio foi determinado pelo declive no gráfico de carga-deflexão em um ensaio de tração. Ademais, a composição química da superfície foi avaliada por um espectrômetro de fluorescência de raios X por energia dispersiva. Resultados: todos os grupos, exceto o G2, produziram níveis de força semelhantes, inicialmente. O G3 produziu as maiores taxas de C/D, enquanto G1 e G4 tiveram quantidades similares de sobreposição das extensões verticais das TLSs em posição neutra. G1 e G3 geraram os mais altos níveis de momentos, enquanto G2 e G3 produziram os mais altos índices de M/F. Os fios -Ti do G3 produziram o maior MY, e todos os grupos apresentaram composição semelhante, exceto G2. Conclusão: os quatro fios de beta-titânio analisados produziram diferentes sistemas de forças, quando utilizados para formas mais complexas, devido ao fato de que cada fio responde de forma diversa à confecção de dobras.

Considerações mecânicas sobre a verticalização de molar inferior associada à ancoragem esquelética temporária: relato de caso / Mechanical considerations about mandibular molar uprighting with skeletal anchorage: case report

A verticalização de molares é um movimento frequente na clínica ortodôntica, no entanto, a maioria das mecânicas empregadas causa a extrusão do molar, gerando interferências oclusais, abertura de mordida e problemas periodontais. O propósito deste artigo é a resolução de um caso clínico de verticalização do segundo molar inferior e a apresentação e discussão do sistema de forças do cantilever duplo. As vantagens da técnica do arco segmentado utilizando cantileveres, associadas à ancoragem esquelética com mini-implante, foram abordadas no presente artigo como uma alternativa mecânica para obter maior controle das forças que atuam na verticalização do molar e redução dos efeitos indesejáveis gerados nos dentes adjacentes. Como consideração final, pode-se afirmar que a verticalização de dentes posteriores utilizando um sistema de forças estaticamente determinado, como o cantilever duplo associado à ancoragem esquelética temporária, mostrou-se uma opção de mecânica eficiente com excelente controle vertical.

Molar uprighting is a common movement in orthodontic practice, however, most of the applied mechanical cause molar extrusion, creating occlusal interferences, bite opening, and periodontal problems. The purpose of this paper is to present a case of a lower second molar uprighting and a discussion about force system with double cantilevers. The advantages of the segmented arch technique using cantilevers, associated with skeletal anchorage with mini-implants, were addressed in this article as a mechanical alternative to obtain greater control of the forces acting on the molar uprighting and reduction of the undesirable effects on the adjacent teeth. As a final consideration, it can be said that the uprighting of posterior teeth using a statically determined system of forces, as double cantilever associated with temporary skeletal anchorage, proved to be an efficient mechanical option with excellent vertical control.

Vertical microgap and passivity of fit of three-unit implant-supported frameworks fabricated using different techniques.

PURPOSE: This study compared the vertical microgaps of milled zirconia and cobalt-chromium (Co-Cr) implant-supported fixed dental prosthesis frameworks to those seen in one-piece frameworks cast with different techniques. MATERIALS AND METHODS: Two threaded implants were used to simulate the rehabilitation of a maxillary partially edentulous space from the second premolar to the second molar. Three-unit screw-retained prosthetic frameworks were fabricated and divided into the following groups (n = 10 in each group): 1 = cast in Co-Cr using burnout cylinders; 2 = cast in Co-Cr using cast-on Co-Cr cylinders; 3 = one-piece cast in Co-Cr using a passive fitting technique; 4 = milled Co-Cr framework; 5 = milled zirconia framework. The microgap was measured under an optical microscope at ×25. Readings were made with one screw tightened and with both screws tightened. Data were submitted to statistical analysis to enable comparison between groups (α = .05). RESULTS: All frameworks presented microgaps less than 70 µm under all reading conditions, except for group 1 with the readings made on the side opposite the tightened side (124.22 µm). With one screw tightened, the microgap on the tightened side was significantly smaller in groups 2, 3, and 4. On the opposite side, groups 3, 4, and 5 presented significantly smaller microgaps compared to the other groups. When both screws were tightened, the microgap was significantly smaller in groups 2, 3, and 4. CONCLUSION: One-piece cast frameworks associated with a passive fitting technique and milled Co-Cr frameworks presented smaller microgaps than the other fabrication methods and materials that were tested.

Efeito de diferentes níveis de torques na resistência ao destorque do parafuso e dos pilares de duas peças em junções cone-morse. Estudo in vitro / The effect of different torque levels on detorque resistance of a two-piece, cone Morse abutment and screw. An in vitro study

Objetivos: determinar se a quantidade da pré-carga influencia a resistência ao destorque do parafuso e pilar de duas peças com junção cone-morse indexada. Material e métodos: foram utilizados 60 análogos de implantes conexão tipo cone-morse de 11,5° com indexador hexagonal e 60 munhões universal cone-morse parafuso passante (4,5 mm de diâmetro, 2,5 mm de altura cinta de transmucoso e 4 mm de altura, não indexados), divididos em três grupos segundo o torque aplicado: 15 Ncm (G1); 20 Ncm (G2) e 25 Ncm (G3). A análise de variância fator único (Anova) e o teste LSD foram usados para as comparações entre os grupos (nível de significância 5%). Imagens em MEV foram realizadas na cabeça do parafuso e na chave de aplicação de torque. Resultados: os valores médios para os destorques dos parafusos foram: G1=17,48 Ncm, G2=21,16 Ncm e G3=26,42 Ncm, com diferencas estatisticamente significativas (p < 0,001) entre todos os grupos. Os valores médios para os destorques nos pilares foram: G1=15,17 Ncm, G2=19,58 Ncm e G3=21,64 Ncm, sendo (G1 e G2) e (G1 e G3) (p < 0,001); e G2 e G3 (p=0,02). Conclusão: 1) o aumento do torque no parafuso gerou valor médio aumentado do destorque em todos os grupos; 2) o aumento do torque gerou valor médio de destorque equivalente ao torque inicial dado para o G1 e G2, sendo este aumento menor no G3; 3) torques maiores do que os indicados pelo fabricante foram capazes de promover a deformação plástica na cabeça do parafuso após apertos repetidos

Objectives: to determine whether the applied preload influences on detorque resistance of abutment and abutment screw of a two-piece, indexed cone-morse taper connection. Material and methods: Sixty implant analogs (cone-morse taper=11,5 degrees) with internal hexagonal indexing and sixty cone morse universal abutments (4.5 mm diameter, 2.5 mm collar height, and 4 mm in height, non-indexed), were divided into three groups according to applied torques: 15 Ncm (G1); 20 Ncm (G2), and 25 Ncm (G3). The one-way Anova and LSD tests were used for comparisons among groups (at 5% level). Representative SEM images were obtained from screw heads and key drivers. Results: mean detorque abutment screw values were as follows: G1=17.48 Ncm, G2=21.16 Ncm, and G3=26.42 Ncm, with statistically significant differences (p < 0,001) among all tested groups. Also, the mean detorque abutment levels were: G1=15.17 Ncm, G2=19.58 Ncm, and G3=21.64 Ncm, being (G1 and G2); (G1 and G3) (p < 0.001); and G2 and G3 (p=0.02). Conclusion: 1) an increase on abutment screw torque level also increases detorque values for all groups; 2) an increase on abutment torque level provided detorque values proportional to that found in G1 and G2, being this lower for G3; 3) torque values higher than those preconized by the manufacturer lead to plastic deformation at screw heads after repeated tightening sequences

Lower molar uprighting with miniscrew anchorage: direct and indirect anchorage.

Lower molar uprighting has been increasingly indicated in clinical orthodontics, mainly because of adult patients with rehabilitation needs. The aim of this study was to determine the success rate of miniscrew use for lower molar uprighting and to compare the use of direct and indirect anchorage. One hundred and eighty-one miniscrews were inserted in 102 rehabilitation patients, with a mean age of 42.24 years. In 71 patients, indirect anchorage was used (116 miniscrews); in the other 31 patients, direct anchorage was employed (65 miniscrews). The choice of direct or indirect anchorage was determined by the orthodontist according to the force system that would be used for the movement and the bone availability. The overall success rate for miniscrews was 90. 05%; 18 miniscrews failed, including 15 that were used as indirect anchorage and 3 that were used as direct anchorage. Considering the results of this study, it can be concluded that both direct and indirect anchorage can be successfully used for molar uprighting.

Determination of the force systems produced by different configurations of tear drop orthodontic loops.

OBJECTIVE: To determine the mechanical characteristics of teardrop loop with and without helix fabricated using different metal alloy compositions (stainless steel and beta-titanium), submitted to different intensities of bends preactivation (0° and 40°), and with different cross-sectional dimension of the wire used to build these loops (0.017 x 0.025-in and 0.019 x 0.025-in). METHODS: Eighty loops used to close spaces were submitted to mechanical tests. The magnitudes of horizontal force, the moment/force ratio, and the load/deflection ratio produced by the specimens were quantified. Loops were submitted to a total activation of 5.0 mm and the values were registered for each 1.0 mm of activation. For statistic data analysis, a analysis of variance was performed and a Tukey's Multiple Comparison test was used as supplement, considering a 5% level of significance. RESULTS: In general, teardrop loops with helix produced lower magnitudes of horizontal force and load/deflection ratio, and higher moment/force ratio than teardrop loops without helix. Among all analyzed variables, metal alloy composition presented greater influence in the horizontal force and in the load/deflection ratio. The moment/force ratio showed to be more influenced by the preactivation of loops for space closure.

Determination of the force systems produced by different configurations of tear drop orthodontic loops

OBJECTIVE: To determine the mechanical characteristics of teardrop loop with and without helix fabricated using different metal alloy compositions (stainless steel and beta-titanium), submitted to different intensities of bends preactivation (0º and 40º), and with different cross-sectional dimension of the wire used to build these loops (0.017 x 0.025-in and 0.019 x 0.025-in). METHODS: Eighty loops used to close spaces were submitted to mechanical tests. The magnitudes of horizontal force, the moment/force ratio, and the load/deflection ratio produced by the specimens were quantified. Loops were submitted to a total activation of 5.0 mm and the values were registered for each 1.0 mm of activation. For statistic data analysis, a analysis of variance was performed and a Tukey's Multiple Comparison test was used as supplement, considering a 5% level of significance. RESULTS: In general, teardrop loops with helix produced lower magnitudes of horizontal force and load/deflection ratio, and higher moment/force ratio than teardrop loops without helix. Among all analyzed variables, metal alloy composition presented greater influence in the horizontal force and in the load/deflection ratio. The moment/force ratio showed to be more influenced by the preactivation of loops for space closure.

OBJETIVO: determinar as características mecânicas de alças em gota e em gota com helicoide, quando da incorporação de variações na liga metálica (aço inoxidável e beta-titânio), na intensidade de dobras de pré-ativação (0º e 40º) e na secção transversal do fio utilizado para a construção dessas alças (0,017" x 0,025" e 0,019" x 0,025"). MÉTODOS: foram submetidas ao ensaio mecânico 80 alças para fechamento de espaços, sendo quantificadas as magnitudes de força horizontal, proporção momento/força e relação carga/deflexão produzidas pelos corpos de prova. As alças foram submetidas a uma ativação total de 5,0mm, sendo registrados os valores a cada 1,0mm de ativação. No tratamento estatístico dos dados obtidos, foi realizada a análise de variância, sendo essa complementada pelo teste de comparações múltiplas de Tukey, considerando o nível de significância de 5%. RESULTADOS: de maneira geral, as alças em gota com helicoide produziram menores magnitudes de força horizontal e relação carga/deflexão e maiores valores de proporção momento/força do que as alças em gota. Dentre todas as variáveis analisadas, aquela que apresentou uma maior influência na força horizontal e na relação carga/deflexão produzidas pelas alças foi a liga metálica. Já a proporção momento/força mostrou ser influenciada em maior grau pela pré-ativação das alças de fechamento de espaços.

Ancoragem esquelética ortodôntica: distalização de molares e fechamento de espaços com mini-implantes para correção da má oclusão Classe II sub-divisão esquerda / Skeletal anchorage: distalization of molars and spaces closure using miniscrews in the treatment of a Class II sudvision left

Os dispositivos intrabucais convencionais de ancoragem nem sempre são capazes de oferecer grande eficiência e resultam em movimentações dentárias indesejadas que podem comprometer o resultado final ou aumentar o tempo total de tratamento. A utilização de sistemas de ancoragem esquelética representa atualmente uma importante ferramenta na estratégia do tratamento ortodôntico por fornecer ancoragem estacionária, minimizando os efeitos indesejáveis em vários movimentos dentários e sem necessitar da cooperação dos pacientes. Neste relato de caso clínico é abordada a correção de má oclusão de Classe II subdivisão esquerda de Angle, com mecânica de distalização de molares por meio de Helical Bulbous Loop e com a utilização de mini-implantes para ancoragem. O objetivo do tratamento foi plenamente alcançado e, tanto as distalizações dos molares quanto o fechamento de espaço, foram ancorados em mini-implantes. Nenhum efeito colateral foi verificado durante o tratamento decorrente da ancoragem.

Conventional intraoral skeletal devices are not always efficient since they may cause undesirable dental movement that can compromise the final results and prolong the period of treatment. The use of skeletal anchorage systems represents an excellent tool for orthodontic treatment as it generates a stationary anchorage, with minimum unexpected dental movement and does not depend on patient compliance. The present study reports a clinical case of Angle Class II/2 malocclusion (subdivision left) treated with molars distalization using a Helical Bulbous Loop with the aid of iniscrews for anchorage. The aim of the treatment was fully achieved and both the distalization of molars and space closure were obtained through miniscrew anchorage. No side effect of anchorage was observed during treatment.