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In this study, we evaluated the cellular viability of various esthetic, metallic, and nickel-free orthodontic brackets.The sample was divided into 11 groups (n = 8): cellular control, negative control, positive control, metallic, polycarbonate, 2 types of monocrystalline ceramic, 3 types of nickel free, and polycrystalline ceramic brackets. Cell culture (NIH/3T3-mice fibroblasts) was added to the plates of 96 wells containing the specimens and incubated in 5% carbon dioxide at 37°C for 24 hours. Cytotoxicity was analyzed qualitatively and quantitatively. Cell growth was analyzed with an inverted light microscope, photomicrographs were obtained, and the results were recorded as response rates based on modifications of the parameters of Stanford according to the size of diffusion halo of toxic substances. Cell viability was analyzed (MTT assay); a microplate reader recorded the cell viability through the mitochondrial activity in a length of 570 nm. The values were statistically analyzed.All tested brackets had higher cytotoxicity values than did the negative control (P0.05), with the exception Rematitan and Equilibrium (both, Dentaurum, Ispringen, Germany) (P0.05), suggesting low toxicity effects. The values showed that only polycarbonate brackets were similar (P0.05) to the positive control, suggesting high toxicity.The brackets demonstrated different ranges of cytotoxicity; nickel-free brackets had better biocompatibility than the others. On the other hand, polycarbonate brackets were made of a highly cytotoxic material for the cells analyzed.

The early phase of orthodontic tooth movement involves sterile acute inflammation of the periodontal ligament in response to biomechanical forces. Anti-inflammatories are pharmacologic agents used in medical and dentistry clinics. The aim of the study was to analyse the bone remodelling during orthodontic movement under non-steroidal and steroidal treatment. Male Wistar rats (n = 90) were randomly divided into three groups: C (control), non-steroidal anti-inflammatory drug (NSAID; potassium diclofenac), and steroidal anti-inflammatory drug (SAID; dexamethasone dissodium phosphate). The animals of the C group received 0.9 per cent saline solution, the NSAID group received potassium diclofenac CATAFLAM® (5 mg/kg), and the SAID group received dexamethasone dissodium phosphate DEXANIL® (2 mg/kg). Animals were sacrificed 3, 7, or 14 days after placement of the orthodontic appliance. The upper first molars were processed histologically; we quantified the blood vessels, Howship lacunae, and osteoclast-like cells present on the tension and compression sides of the periodontal ligament. Bone formation was evaluated under polarized light microscopy; 4.5 Image Pro-Plus® software calculated the percentage of immature/mature collagen present. The results showed that, in 3 and 7 days, NSAID and SAID groups presented fewer blood vessels, Howship lacunae, and osteoclast-like cells when compared to the control group. On the 7th and 14th days, there was a lower percentage of mature collagen in the SAID group (P < 0.001). These data demonstrate that potassium diclofenac and dexamethasone inhibit bone resorption during the initial period of orthodontic movement and that dexamethasone delays the collagen maturation process in established bone matrix.

There is controversy in the literature about possible interaction of the respiratory mode with the facial and dental structures. OBJECTIVES: The aim of this study was to perform a longitudinal assessment of the changes in facial and dental structures in Angle's Class II, division 1 malocclusion individuals, divided according to the respiratory pattern (predominantly nasal or mouth), at two distinct moments of craniofacial development. MATERIAL AND METHODS: Pogonium and nose measurements were made on the lateral cephalometric tracings (LS'-Pog', LS'-B', B'-Pog', Pog'-PogTeg', Line NB, Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn, Prn-Sn-LS). Dental measurements were made on the plaster models (distances between the tips of the canine cusps and the tips of mesial cusps of the first molars) of 40 individuals aged 10 to 14 years (moment 1) and 13 to 16 years (moment 2), 23 being nose breathers (NB) and 17 being predominantly mouth breathers (MB). RESULTS: The Student's-t test and two-way ANOVA with repeated measures were applied to indicate differences between the mean values of these variables according to the moments and/or respiratory mode. CONCLUSIONS: There were alterations in the facial measurements, without interference of the breathing pattern. However, the breathing pattern infuenced dental alterations.

The organic matrix of alveolar bone is composed fundamentally of type I collagen. Polarized light microscopy provides unique information about the structure, composition and polymerization degree of a variety of organic and inorganic tissues that is not available with other techniques. The aim of this research was to compare two methodologies of polarized light analysis for collagen organization in bone formation during orthodontic tooth movement and determined maturity of collagen over the time. Thirty Wistar rats were euthanized 3, 7 and 14 days after the NiTi unilateral closed-coil spring was stretched between the upper right first molar and the incisors. The control consisted by contra-lateral site. The first molar area was fixed, decalcified and histologically processed using picrosirius pigment. The collagen birefringence of bone turnover was analyzed by color percentage and phase retardation. We observed an increase in collagen fiber organization over time with two methodologies. The Pearson coefficient correlation indicated a strong relationship (0.76) among the two polarized light analyses. In summary, there is collagen maturation over 3, 7 and 14 days. We successfully evaluated the molecular organization, arrangement, degree of polymerization and maturation process of collagen fibers in bone turnover through color percentages and phase retardation.

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, 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.

INTRODUCTION: The teeth position, specially maxillary and mandibular incisors, in relation to basal bone and surrounding soft tissues must be considered in the elaboration of diagnosis, treatment planning and execution to obtain alignment, leveling, intercuspation, facial balance and harmony with stability of results. OBJECTIVES: To evaluate the modifications in the positioning of incisors in individuals with Angle Class II, division 1 malocclusion in two distinct moments of dentocraniofacial development, with mean interval of 2 years and 5 months. METHODS: The measures were obtained by means of lateral cephalograms of 40 individuals, being 23 nasal breathers (NB) and 17 mouth breathers (MB). The analyzed measures were overjet, overbite, UCI-NA, LCI-NB, UCI.NA, LCI.NB, UCI.SN, LCI.GoGn, UCI.LCI, ANB, GoGn.SN, and OccPl.SN. Statistical analysis (2-way repeated-measures ANOVA) was applied to verify intergroups differences. RESULTS: Overjet, UCI-NA, LCI-NB, ANB, GoGn.SN, and OccPl.SN demonstrated statistically significant difference (p < 0.05) when observed the moment or the respiratory method. CONCLUSION: There is alteration in the positioning of incisors during growth with interference of the respiratory pattern. INTRODUÇÃO: a posição dos dentes, principalmente incisivos superiores e inferiores, em relação às bases ósseas e tecidos moles circundantes deve ser considerada na elaboração do diagnóstico, planejamento e execução do tratamento, para se obter alinhamento, nivelamento, intercuspidação, equilíbrio e harmonia facial com estabilidade dos resultados. OBJETIVOS: avaliar as modificações no posicionamento dos incisivos em indivíduos com má oclusão de Classe II, divisão 1, de Angle, em dois momentos distintos do desenvolvimento dentocraniofacial, num intervalo médio de 2 anos e 5 meses. MÉTODOS: as medidas foram obtidas por meio de telerradiografias em norma lateral de 40 indivíduos, sendo 23 respiradores predominantes nasais (RN) e 17 predominantemente bucais (RB). As medidas avaliadas foram sobressaliência, sobremordida, ICS-NA, ICI-NB, ICS.NA, ICI.NB, ICS.SN, ICI.GoGn, ICS.ICI, ANB, GoGn.SN, Plo.SN. Para verificar a diferença intergrupos, utilizou-se a ANOVA a dois critérios com medidas repetidas. RESULTADOS: sobressaliência, ICS-NA, ICI-NB, ANB, GoGn.SN, Plo.SN apresentaram diferença estatisticamente significativa (p < 0,05) quando observado o momento ou o modo respiratório. CONCLUSÃO: existe alteração no posicionamento dos incisivos no decorrer do crescimento, com interferência do modo respiratório.

INTRODUCTION: Tooth movement is initially characterized by an acute sterile inflammation, followed by sequential multiple reactions in the periodontal ligament in response to biomechanical forces. Pharmacological agents such as corticosteroids may affect the course of orthodontic movement. Scientific studies show antagonistic actions of these drugs on bone resorption during tooth movement. OBJECTIVE: To review the literature about the effect of corticosteroids on orthodontic tooth movement. CONCLUSION: Patients should be questioned regarding the use of these drugs in the orthodontic practice and for those who use them, the orthodontic treatment should be differentiated, with longer intervals between visits and periodic X-rays due to the delay in bone formation observed in some scientific studies.INTRODUÇÃO: a movimentação dentária é caracterizada, inicialmente, por uma inflamação aguda estéril, seguida por reações múltiplas sequenciais no ligamento periodontal em resposta às forças biomecânicas. Agentes farmacológicos, como os corticosteroides, podem alterar o curso da movimentação ortodôntica. Os estudos científicos demonstram ações antagonistas dessas drogas sobre a reabsorção óssea durante a movimentação dentária. OBJETIVO: realizar revisão de literatura sobre a ação dos corticosteroides no movimento dentário ortodôntico. CONCLUSÃO: os pacientes devem ser questionados quanto ao uso dessas drogas na clínica ortodôntica e, para aqueles que fazem uso, o tratamento ortodôntico deve ser diferenciado, com intervalos maiores entre as consultas e solicitação periódica de radiografias devido ao atraso na neoformação óssea observado em alguns estudos científicos.

INTRODUÇÃO: o perfil mole do indivíduo é resultado de mudanças complexas que ocorrem nos tecidos duros e moles das estruturas faciais. O pogônio e o nariz são estruturas dominantes na face e influenciam no grau de convexidade do perfil. Assim, é fundamental a análise das estruturas do pogônio e a inclusão das estruturas nasais no plano de tratamento ortodôntico. OBJETIVO: avaliar longitudinalmente as modificações dimensionais no plano anteroposterior do pogônio e do nariz de indivíduos com má oclusão de Classe II, divisão 1 de Angle, em dois momentos distintos do desenvolvimento craniofacial. MÉTODOS: foram realizados traçados cefalométricos sobre telerradiografias em norma lateral de 40 indivíduos, sendo 23 respiradores predominantemente nasais (RN) e 17 predominantemente bucais (RB). RESULTADOS: foram obtidas as medidas lineares e angulares LS'-Pog', LS'-B', B'-Pog', Pog'-PogTeg', Linha NB, Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn e Prn-Sn-LS. O teste ANOVA a dois critérios com medidas repetidas foi aplicado para indicar diferenças entre os valores médios dessas variáveis segundo os momentos e/ou modo respiratório. Observou-se que as variáveis LS'-B', Pog'-PogTeg', Linha NB e Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn e Prn-Sn-LS apresentaram diferença significativa (p

Este estudo avaliou a resistência de união entre o conjunto resina composta/adesivo e diferentes tipos de substrato dentinário. Quinze molares humanos extraídos foram divididos em três grupos de acordo com o tipo de dentina: 5 dentes com dentina afetada por cárie (C), 5 restaurados com amálgama (R) e 5 dentes hígidos (H). Todos os dentes tiveram sua superfície oclusal desgastada até expor uma superfície dentinária plana. As diferentes superfícies foram condicionadas com ácido fosfórico a 37% (3M ESPE), seguindo-se a aplicação e fotopolimerização do adesivo Single Bond (3M ESPE) para a imediata inserção de incrementos de 1 mm de resina composta (Z250 – 3M ESPE) até atingir 4 mm de altura. Após 24 horas de armazenagem em água destilada (37ºC), os corpos-de-prova em forma de palito com secção transversal de 1 mm2 de área foram submetidos ao ensaio de microtração (Instron). A análise estatística (ANOVA/Tukey) revelou que o fator substrato interferiu na resistência adesiva (p

OBJECTIVES: To determine the influence of the light curing units on the shear bond strength of orthodontic brackets. MATERIAL AND METHODS: Seventy-two premolars were divided into six groups (n=12): Group I: brackets bonded with Transbond and polymerization with halogen light; Group II: Transbond and LED; Group III: Fuji Ortho and halogen light; Group IV: Fuji Ortho and LED; Group V: Fuji Ortho, without acid and halogen light; Group VI: Fuji Ortho, without acid and LED. The groups were tested to shear strength in a universal testing machine at a crosshead speed of 0.5 mm/min. Data were analyzed statistically by ANOVA and Tukey's test. RESULTS: The composite resin presented higher shear bond strength than the resin-modified glass ionomer cement (p0.05). CONCLUSION: The shear bond strength was influenced by the material but not by the light-curing unit. The use of LED reduced the experimental time by approximately 60%, with the same curing efficiency.

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

OBJECTIVE: To evaluate the influence of saliva contamination on shear bond strength and the bond failure pattern of 3 adhesive systems (Transbond XT, AdheSE and Xeno III) on orthodontic metallic brackets bonded to human enamel. MATERIAL AND METHODS: Seventy-two permanent human molars were cut longitudinally in a mesiodistal direction, producing seventy-two specimens randomly divided into six groups. Each system was tested under 2 different enamel conditions: no contamination and contaminated with saliva. In T, A and X groups, the adhesive systems were applied to the enamel surface in accordance with manufacturer's instructions. In TS, AS and XS groups, saliva was applied to enamel surface followed by adhesive system application. The samples were stored in distilled water at 37ºC for 24 h, and then tested for shear bond strength in a universal testing machine (Emic, DL 2000) running at a crosshead speed of 1 mm/min. After bond failure, the enamel surfaces were observed under an optical microscope at 40x magnification. RESULTS: The control and contaminated groups showed no significant difference in shear bond strength for the same adhesive system. However, shear bond strength of T group (17.03±4.91) was significantly higher than that of AS (8.58±1.73) and XS (10.39±4.06) groups (p

Introduction Ameloblastomas are benign asymptomatic intraosseous lesions that affect the bones of the maxillomandibular complex, interfering both in function and facial esthetic appearance. A 14-year-4-month-old girl was referred by her clinician complaining her anterior teeth were crooked and inclined forward. The lower left mandibular tooth presented with increased pericoronal space compatible with dentigerous cyst. Methods and Results The aim of this report is to relate a case of unicystic ameloblastoma with conservative treatment and with indication for orthodontic treatment. The conservative therapy was performed and the lesion had been completely removed. The need for radiographic and clinical follow-up for up to 10 years, initially performed every 6 months during the first 2 years and afterwards annually, in addition to the risk of late recurrence were explained for patient and her guardian. Conclusion The histopathologic exam of the surgical tissue provided the final diagnosis of ameloblastoma, as the lesion had not presented in its classical form and in atypical locations, as in this case involving a tooth that had not yet erupted.

O objetivo desta pesquisa foi avaliar, in vitro, a influência do tipo de adesivo na resistência de união de “brackets” metálicos colados ao esmalte de dentes humanos. Trinta molares humanos extraídos foram incluídos em tubos de PVC e aleatoriamente divididos em três grupos (n=10): Grupo I – “bracket” colado com Transbond (3M/Unitek), Grupo II – “bracket” colado com AdheSE (Ivoclar/Vivadent) e Grupo III – “bracket” colado com Xeno III (Dentsply). O preparo da superfície de esmalte foi realizada profilaxia, seguido da aplicação dos adesivos conforme instruções dos fabricantes. Os “brackets” metálicos (Morelli®) foram colados na porção central de cada fragmento com resina fotoativada Transbond XT (3M/Unitek). Os corpos-de-prova foram armazenados em água destilada a 37ºC durante 24 horas. Em seguida, foram submetidos ao teste de cisalhamento em máquina de ensaio universal (EMIC, DL 2000), com velocidade de 1 mm/minuto e ao Índice de Adesivo Remanescente (IAR). A análise estatística (ANOVA/Tukey) demonstrou que o fator adesivo não influencia a resistência de união ao cisalhamento. Dessa forma, os adesivos autocondicionantes são uma boa alternativa para a colagem de “brackets” metálicos. The aim of this in vitro study was evaluate the influence of the adhesive type in the shear bond strength of metallics brackets to the dental enamel. Thirty molars human were placed into PVC rings and randomly divided into three groups (n=10). Group I - bracket bonded with Transbond (3M/Unitek), Group II – bracket bonded with AdheSE (Ivoclar/ Vivadent) and Group III – bracket bonded with Xeno III (Dentsply). The enamel surface was subjected to prophylaxis, followed by application of the adhesive systems, accor-ding to the manufacturer’s recommendations. The metallic brackets (Morelli®) were bonded in the central portion of the fragments with light-cure resin Transbond XT (3M/ Unitek). The specimens were stored in distilled water at 37ºC for 24 hours. The samples were then submitted to shear bond strength in a universal testing machine EMIC DL2000 at a cross-head speed of 1 mm/minute and Index of Remainder Adhesive (ARI). The statistical analyses (ANOVA/ Tukey) showed the adhesive system didn’t influence the shear bond strength. In that way, the self-etching primers are a good alternative for the metallic brackets bonding.