Potentialities and limitations of computer-aided design and manufacturing technology in the nonextraction treatment of Class I malocclusion.

INTRODUCTION: Computer-aided design and manufacturing (CAD-CAM) systems have assisted orthodontists to position brackets virtually. The purpose of this study was to evaluate if a CAD-CAM system could predict the orthodontic treatment outcome of patients with Angle Class I malocclusion with mild crowding or spacing and with no need for orthodontic extraction. METHODS: Using the American Board of Orthodontics Cast-Radiograph Evaluation (ABO-CRE) and color map superimposition, the treated occlusion was compared with the virtual final occlusion of 24 young adults with Class I occlusion. Using eXceed software (eXceed, Witten, Germany), we created the final occlusion prediction for each patient (virtual set up group). A digital model of the final occlusion of each patient was created (treated occlusion group). ABO-CRE score was used to compare groups. In addition, a color map was created for all subjects to access the mean and range values between the virtual set up model and treated occlusion model of each patient. Random and systematic errors were calculated. In addition, chi-square and t test were used. RESULTS: Comparisons between virtual set up occlusion and treated occlusion showed statistically significant differences in 3 out of 7 measurements: interproximal contact score was larger for treated than virtual occlusion (0.45 mm and 0.04 mm, respectively), and the treated occlusion showed larger values than the virtual occlusion for occlusal contacts (14.13 mm and 7.62 mm, respectively) and overjet (7.37 mm and 0.66 mm, respectively). Although the treated occlusion showed a larger score than the virtual occlusion (50.41 mm and 34.58 mm, respectively), there is no significant difference between both. Root angulation decreased (from 1.95 ± 1.29 to 0.65 ± 0.71) because of the treatment. CONCLUSIONS: ABO-CRE overall score presents no difference between groups. In addition, CAD-CAM setup occlusion closely predicts the final teeth alignment and leveling with interarch relationships showing less ABO-CRE score deduction.

Effect of Yd:YAG laser irradiation on the shear bond strength of orthodontic metal brackets.

OBJECTIVE: The purpose of this study was to evaluate the effect of the Yd:YAG laser irradiation on orthodontic bracket base surface. Shear bond strength (SBS) values and sites of the bonding failure interfaces were quantified. METHODS: Brackets were divided into two groups: OP (One Piece - integral sandblast base) and OPL (One Piece - laser irradiation). The brackets were randomly bonded on an intact enamel surface of 40 bovine incisors. The SBS tests were carry out using a universal test machine. A stereomicroscopy was used to evaluate the adhesive remnant index (ARI), and surface characterization was performed by scanning electron microscopy (SEM). Student's t-test was used to compare the SBS between the two groups (p< 0.05). Frequencies and chi-square analysis were applied to evaluate the ARI scores. RESULTS: OPL group showed higher value (p< 0.001) of SBS than OP group (43.95 MPa and 34.81 MPa, respectively). ARI showed significant difference (p< 0.001) between OPL group (ARI 0 = 100%) and OP group (ARI 0 = 15%). SEM showed a higher affinity between the adhesive and the irradiated laser base surface. CONCLUSIONS: Yd:YAG laser irradiation on bracket base increased SBS values, showing that bonding failure occurs at the enamel/adhesive interface. Laser-etched bracket base may be used instead of conventional bases in cases where higher adhesion is required, reducing bracket-bonding failure.

Effect of Yd: YAG laser irradiation on the shear bond strength of orthodontic metal brackets

ABSTRACT Objective: The purpose of this study was to evaluate the effect of the Yd:YAG laser irradiation on orthodontic bracket base surface. Shear bond strength (SBS) values and sites of the bonding failure interfaces were quantified. Methods: Brackets were divided into two groups: OP (One Piece - integral sandblast base) and OPL (One Piece - laser irradiation). The brackets were randomly bonded on an intact enamel surface of 40 bovine incisors. The SBS tests were carry out using a universal test machine. A stereomicroscopy was used to evaluate the adhesive remnant index (ARI), and surface characterization was performed by scanning electron microscopy (SEM). Student's t-test was used to compare the SBS between the two groups (p< 0.05). Frequencies and chi-square analysis were applied to evaluate the ARI scores. Results: OPL group showed higher value (p< 0.001) of SBS than OP group (43.95 MPa and 34.81 MPa, respectively). ARI showed significant difference (p< 0.001) between OPL group (ARI 0 = 100%) and OP group (ARI 0 = 15%). SEM showed a higher affinity between the adhesive and the irradiated laser base surface. Conclusions: Yd:YAG laser irradiation on bracket base increased SBS values, showing that bonding failure occurs at the enamel/adhesive interface. Laser-etched bracket base may be used instead of conventional bases in cases where higher adhesion is required, reducing bracket-bonding failure.

RESUMO Objetivo: O objetivo do presente estudo foi avaliar o efeito da aplicação do laser Yd:YAG sobre a superfície metálica da base de braquetes ortodônticos, a resistência da colagem ao cisalhamento (RU) e os locais das falhas nas interfaces adesivas. Métodos: Os braquetes foram divididos em dois grupos, de acordo com o tipo de base: OP (One Piece - monobloco, base jateada) e OPL (One Piece - monobloco, base irradiada a laser). Foram selecionados 40 incisivos bovinos hígidos para a colagem de braquetes na superfície do esmalte. Os testes de RU foram realizados por meio de uma máquina de ensaio universal EMIC DL1000. O Índice de Adesivo Remanescente (ARI) e a caracterização das superfícies foram realizados empregando-se estereomicroscópio e microscópio eletrônico de varredura (MEV). O teste t de Student foi aplicado para comparar a RU entre os dois grupos (p< 0,05). O ARI foi avaliado por meio da análise de Frequência e teste do Qui-quadrado. Resultados: O grupo OPL obteve maiores valores de RU (p<0,001) do que o grupo OP (43,95 MPa e 34,81 MPa, respectivamente), e o ARI obteve diferença significativa (p<0,001) entre os grupos OPL (ARI 0 = 100%) e OP (ARI 0 = 15%). A análise proveniente do MEV mostrou alta interação adesiva entre a resina e a superfície metálica da base irradiada pelo feixe de laser. Conclusões: A irradiação com laser Yd:YAG sobre a superfície da base de braquetes metálicos aumentou os valores da RU, demonstrando que as falhas adesivas ocorreram na interface esmalte/adesivo. O uso de braquetes modificados com irradiação a laser pode ser adotado como alternativa aos braquetes com bases convencionais nos casos em que uma maior retentividade for requerida para reduzir as falhas de adesividade.

O uso da tecnologia CAD/CAM na Ortodontia ­ setup ortodôntico e colagem indireta pelo sistema eXceed™ / The CAD/CAM technology in Orthodontics ­ Orthodontic setup and indirect bonding using the eXceedTM System

Os sistemas CAD/CAM, incluindo o sistema eXceed™, possibilitam aos ortodontistas a realização de diagnóstico, planejamento de casos clínicos e posicionamento virtual de bráquetes. A posição de cada acessório, determinada pelo software, é transferida para o modelo tridimensional do paciente sobre o qual um dispositivo de transferência para colagem indireta (CI) de bráquetes é produzido. A CI permite uma melhoria na precisão da colagem de acessórios ortodônticos, diminuindo o tempo e o custo do tratamento devido a uma menor necessidade de dobras de finalização e reposicionamento de bráquetes. O caso clínico apresentado tem o objetivo de apresentar um tratamento ortodôntico utilizando o método de CI com posicionamento virtual de bráquetes idealizado pelo sistema eXceed™. O posicionamento dos bráquetes programado pelo sistema eXceed™ permitiu um posicionamento "ideal" dos dentes dispensando a implementação de dobras de finalização e proporcionando uma oclusão equilibrada. Essa nova tecnologia demonstrou ser eficiente e eficaz, e o setup ortodôntico fornecido pelo sistema ficou acordante com o resultado final do tratamento ortodôntico (AU)

CAD/CAM systems, including the eXceed™ system, allow orthodontists to perform diagnosis, treatment plan, and brackets virtual positioning. The positioning of each bracket, determined by the software, is transferred to a tridimensional patient model enabling to build an indirect bonding (IB) tray. IB allows improvement in the ideal bracket positioning, decreasing treatment time and cost due to less detailed finishing bends and/or bracket repositioning. The clinical case report purpose is to present an orthodontic treatment using IB with virtual bracket positioning using eXceed™ system. The bracket virtual positioning from eXceed™ system allowed an ideal final teeth positioning eliminating detailed finishing bends and reaching the ideal occlusion as planned. This new technology has shown to be efficient and effective, and the virtual tridimensional orthodontic setup has been in agreement with the final treatment occlusion (AU)

Acurácia e confiabilidade de modelos digitais tridimensionais ­ validação do software eXceedtm / Three-dimensional digital models accuracy and reliability ­ eXceedtm software validation

Resumo Introdução: Os sistemas CAD/CAM auxiliam ortodontistas na confecção de alinhadores estéticos e na colagem indireta (posicionamento virtual de bráquetes) em modelos digitais tridimensionais. Este estudo avaliou a precisão e validade do software eXceedTM. Métodos: Vinte modelos de gesso de pacientes foram digitalizados utilizando um escâner de mesa e os arquivos obtidos foram convertidos em estereolitografia pelo software OrthoAnalyserTM. Utilizando os modelos de gesso e digital, seis medidas foram aferidas: Largura Intermolares (LM), Largura Intercaninos (LC), Comprimento do Arco posterior (CA), Diâmetro da Coroa do Pré-Molar (DP), Altura da Coroa do Canino (AC) e Overjet (OJ). Os erros sistemáticos e aleatórios foram avaliados em análises das réplicas das mensurações. As diferenças foram avaliadas usando o teste t de Student. Os erros aleatórios foram quantificados usando o erro do método (V(Sd2/2n) e o Coeficiente de Correlação Intraclasse (ICC). Resultados: Duas das medidas das réplicas em modelos digitais (CA) e de gesso (LC) demostraram erros sistemáticos estatisticamente significativos. O ICC variou de 0,916 a 0,997. Os erros do método foram todos inferiores a 0,41 mm (0,22 mm). Os gráficos de Bland-Altman mostraram que as diferenças de repetitividade entre os dois métodos estavam dentro dos limites de concordância. Os valores DP (0,253 mm), LC (0,396 mm), AC (0,314 mm) e CA (0,359 mm) foram maiores em modelos de gesso do que nos modelos digitais. Conclusão: As medidas realizadas em ambos os métodos foram confiáveis e reprodutíveis, e as medidas dos modelos de gesso foram ligeiramente maiores do que os dos modelos digitais correspondentes (AU)

Abstract Introduction: CAD/CAM systems help orthodontists in the production of aesthetic aligners and in indirect bonding (virtual bracket positioning) in three-dimensional digital models. This study evaluated the accuracy and validity of the eXceedTM 3D software (Roosikrantsi, Tallinn, Estonia). Methods: Twenty patient plaster models were digitized by a desktop scanner, and the files obtained were converted to stereolithography by OrthoAnalyserTM software. Using the cast and digital models, six measurements were performed: Intermolar Width (LM); Intercanine Width (LC); Posterior Arch Length (CA); Premolar Crown Diameter (DP); Canine Crown Hight (AC) and Overjet (OJ). Intra-observer systematic differences between the replicates were described with mean absolute differences and standard errors (SE); differences were assessed using a paired Students t test. Random errors were quantified using the method error statistic (V[Sd2/2n]) and Intraclass Correlation Coefficient (ICC). Differences between methods was evaluated using Students t test. Results: Two of the measurements of the replicas in the digital model (CA) and in the plaster model (LC) showed statistically significant systematic errors. The ICC ranged from 0.916 to 0.997. The method errors were all less than 0.41 mm (0.22 mm). Bland-Altman plots showed that the differences of repeatability between the two methods were within the limits of agreement. The values DP (0.253 mm), LC (0.396 mm), AC (0.314 mm) and CA (0.359 mm) were higher in plaster models than in digital models. Conclusion: The measurements performed in both methods were reliable and reproducible, and plaster models measurements were slightly higher than those of the corresponding digital models. (AU)

Sarcoidose hepática associada a esteato-hepatite não alcoólica (EHNA) / Hepatic sarcoidosis associated to nonalcoholic steatohepatitis

Os autores relatam o caso de uma paciente portadora de síndrome metabólica, apresentando-se com poucos sintomas, radiografia de tórax normal e elevação de enzimas hepáticas. Estudo histopatológico evidenciou alterações compatíveis com NASH em associação com granulomas não caseosos portais. Posteriormente, foi firmado o diagnóstico de sarcoidose, obtendo-se boa resposta com corticoterapia associada às medidas para tratamento da NASH.