RESUMO Introdução: A utilização da tecnologia digital tem contribuído para aprimorar e facilitar o diagnóstico, planejamento e execução dos tratamentos ortodônticos. Entre as diversas aplicações do sistema CAD/CAM (Computer-Aided Design / Computer-Aided Manufacturing) destacamos a sequência clínica de tratamento ortodôntico com aparelho fixo, tratamentos com alinhadores estéticos, aparelhos personalizados sobre mini-implantes e confecção de contenções totalmente em ambiente digital. Essa abordagem apresenta diversas vantagens para o profissional e o paciente, na medida em que aumenta a precisão dos aparelhos, interfere diretamente no tempo de tratamento e na previsibilidade do resultado. Embora os benefícios decorrentes do fluxo de trabalho digital sejam evidentes, poucos ortodontistas adotaram essa técnica na prática clínica, principalmente devido ao custo elevado e à falta de preparo técnico para a adequada execução. Objetivo: Dessa forma, diante da importância da utilização da tecnologia digital para aprimorar a atuação ortodôntica e da ainda incipiente incorporação do fluxo digital na prática clínica, o objetivo do presente artigo é apresentar recursos disponíveis e aplicações clínicas da tecnologia CAD/CAM na Ortodontia.

ABSTRACT Introduction: The digital technology has contributed to improve and simplify diagnosis, treatment planning and execution in Orthodontics. Among CAD/CAM system (Computer-Aided Design / Computer-Aided Manufacturing) applications in Orthodontics, we highlight the installation and removal of fixed appliance, clear aligners, customized appliances, and retainers fabricated in digital environment. This approach has several advantages for practitioner and patient, as it enhances appliances precision, directly interferes in treatment time and predictability. Even with all the benefits arising from the digital workflow, few orthodontists have adopted this technique in their clinical practice, most due to high cost and lack of technical preparation for proper execution. Objectives: Thus, given the importance of digital technology to improve specialty performance and the still incipient incorporation of digital flow in Orthodontics, the purpose of this article is to describe the available resources and clinical applications of the CAD/CAM technology in Orthodontics.

OBJETIVO: avaliar, in vitro, a citotoxicidade de resinas acrílicas autopolimerizáveis, de diferentes cores, ao longo do tempo. MÉTODOS: os corpos de prova foram divididos em quatro grupos (n = 3), de acordo com a cor da resina acrílica utilizada (Orto Class, Clássico, São Paulo/SP), sendo: grupo 1, acrílica incolor; grupo 2, acrílica rosa; grupo 3, acrílica azul; e, grupo 4, acrílico verde. Todos os corpos de prova foram confeccionados pela técnica de massa e polidos mecanicamente. Um corpo de prova de amálgama, um de vidro e célula constituíram o controle positivo (C+), controle negativo (C-), e controle de célula (CC), respectivamente. Em seguida, esses foram imersos em meio mínimo essencial de Eagle (MEM) por 24h, quando se removeu o sobrenadante e colocou-os em contato com fibroblastos L929. Avaliou-se a citotoxicidade em quatro períodos: 24, 48, 72 e 168h. Após o contato com o meio, as células foram incubadas por 24h e adicionou-se 100µ do corante vermelho neutro a 0,01%. Posteriormente, as células foram incubadas por 3h, para incorporação do corante, e fixadas. A contagem das células viáveis foi realizada em espectrofotômetro (BioTek, Winooski, EUA), com um comprimento de onda de 492nm (λ = 492nm). RESULTADOS: não houve diferença estatística entre os grupos experimentais e os grupos CC e C-. CONCLUSÇÕES: as resinas acrílicas autopolimerizáveis incolor, rosa, azul e verde, manipuladas pela técnica de massa e polidas mecanicamente não são citotóxicas. O corante utilizado em resinas autopolimerizáveis e tempo não influenciam na citotoxocidade do material.

OBJECTIVE: The aim of this study was to assess the in vitro cytotoxicity of acrylic resins of different colors over time. METHODS: Specimens were divided into 4 groups (n = 6) according to the color of the acrylic resin (Orto Class, Clássico, Campinas, São Paulo, Brazil): Group 1: clear acrylic resin; group 2: pink acrylic resin; group 3: blue acrylic resin and group 4: green acrylic resin. All specimens were fabricated according to the mass manipulation technique and submitted to mechanical polishing protocol. The control was performed with an amalgam specimen (C+), a glass specimen (C-) and cell control (CC). Specimens were immersed in Minimum Eagle's Medium (MEM) and incubated for 24 h at 37o C. The extracts from the experimental material were filtered and mixed with L929 fibroblast. Cytotoxicity was evaluated at 4 different times, 24, 48, 72 and 168 h. After contact, cells were incubated for 24 h and added to 100 µ of 0.01% neutral red dye. The cells were incubated for 3 h for pigment incorporation and fixed. Cells viability was determined by a spectroscopic (BioTek, Winooski, Vermont, USA) with a 492-nm wavelength λ=492 nm). RESULTS: There were no statistical differences between the experimental groups and the CC and C- groups. CONCLUSION: Clear, pink, blue and green self-curing acrylic resins fabricated by means of the mass manipulation technique and mechanically polished are not cytotoxic. Neither the pigment added to the self-curing acrylic resin nor the factor of time influenced the cytotoxicity of the material.

OBJETIVO: avaliar a influência da contaminação por saliva na resistência de união de braquetes metálicos colados ao esmalte com um compósito resinoso hidrofílico. MÉTODOS: oitenta pré-molares foram divididos aleatoriamente em quatro grupos (n=20), de acordo com o material de colagem e a presença de contaminação - G1) colagem com Transbond XT na ausência de contaminação; G2) colagem com Transbond XT na presença de contaminação; G3) colagem com Transbond Plus Color Change na ausência de contaminação; G4) colagem com Transbond Plus Color Change na presença de contaminação. Os resultados foram tratados estatisticamente (ANOVA/Tukey). RESULTADOS: as médias e desvios-padrão (MPa) foram G1 = 10,15 ± 3,75; G2 = 6,8 ± 2,54; G3 = 9,3 ± 3,36; G4 = 8,3 ± 2,95. O índice de adesivo remanescente (IAR) variou entre 0 e 1 no G1 e no G4; no G2, houve predomínio do escore 0 e distribuição similar no G3. CONCLUSÃO: a contaminação por saliva reduziu a resistência de união no grupo que usou a resina hidrofóbica Transbond XT. Por outro lado, a resina hidrofílica Transbond Plus Color Change não foi influenciada pela contaminação.

OBJECTIVE: To evaluate the influence of saliva contamination on the bond strength of metallic brackets bonded to enamel with hydrophilic resin composite. METHODS: Eighty premolars were randomly divided into 4 groups (n = 20) according to bonding material and contamination: G1) bonded with Transbond XT with no saliva contamination, G2) bonded with Transbond XT with saliva contamination, G3) bonded with Transbond Plus Color Change with no saliva contamination and G4) bonded with Transbond Plus Color Change with saliva contamination. The results were statistically analyzed (ANOVA/Tukey). RESULTS: The means and standard deviations (MPa) were: G1)10.15 ± 3.75; G2) 6.8 ± 2.54; G3) 9.3 ± 3.36; G4) 8.3 ± 2.95. The adhesive remnant index (ARI) ranged between 0 and 1 in G1 and G4. In G2 there was a prevalence of score 0 and similar ARI distribution in G3. CONCLUSION: Saliva contamination reduced bond strength when Transbond XT hydrophobic resin composite was used. However, the hydrophilic resin Transbond Plus Color Change was not affected by the contamination.

OBJECTIVE: The aim of this study was to assess the impact of blood contamination on shear bond strength (SBS) and bond failure pattern of metallic brackets bonded using a new hydrophilic resin. MATERIAL AND METHODS: Eighty human premolars were randomly allocated into 4 groups (n=20) according to the bonding material and contamination pattern. GI: brackets bonded with the Transbond XT conventional system without contamination; GII: brackets bonded with the Transbond XT conventional system with blood contamination; GIII: brackets bonded with the Transbond Self Etching Primer and Transbond Plus Color without contamination; GIV: brackets bonded with the Transbond Self Etching Primer and Transbond Plus Color with blood contamination. The specimens were stored in distilled water at 37°C for 24 h and then submitted to SBS test at a crosshead speed of 0.5 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: Blood contamination decreased (P<0.05) shear bond strength when both the hydrophobic (GII) and the hydrophilic resin (GIV) were used. However, the bond strength of Transbond Color Change group was significantly higher (P<0.05) than that of the Transbond XT conventional system group under blood contamination condition. Under dry conditions no difference was observed between the hydrophobic and hydrophilic resin groups. Regarding the bond failure pattern, when blood contaminated the enamel, the adhesive remnant index (ARI) showed predominance of scores 0 and 1, which indicates low adhesion to enamel. CONCLUSIONS: Although there was a significant decrease in the shear bond strength for both adhesive systems under blood contamination, the hydrophilic system showed significantly higher bond strength than the hydrophobic resin adhesive. Therefore, it is advisable to use the hydrophilic resin under risk of blood contamination.