Biofilm formation is the preferred mode of growth lifestyle for many microorganisms, including bacterial and fungal human pathogens. Biofilm is a strong and dynamic structure that confers a broad range of advantages to its members, such as adhesion/cohesion capabilities, mechanical properties, nutritional sources, metabolite exchange platform, cellular communication, protection and resistance to drugs (e.g., antimicrobials, antiseptics, and disinfectants), environmental stresses (e.g., dehydration and ultraviolet light), host immune attacks (e.g., antibodies, complement system, antimicrobial peptides, and phagocytes), and shear forces. Microbial biofilms cause problems in the hospital environment, generating high healthcare costs and prolonged patient stay, which can result in further secondary microbial infections and various health complications. Consequently, both public and private investments must be made to ensure better patient management, as well as to find novel therapeutic strategies to circumvent the resistance and resilience profiles arising from biofilm-associated microbial infections. In this work, we present a general overview of microbial biofilm formation and its relevance within the biomedical context.

Resumo Objetivo Avaliar a resistência ao cisalhamento e o índice de remanescente adesivo (IRA) dos bráquetes que tiveram o polímero Primekote® incorporado a suas bases. Material e método Foram confeccionados trinta corpos de prova com incisivos bovinos, divididos em dois grupos: o colado com bráquete TP® Nu-Edge(n=15) e grupo controle com bráquetes Morelli® (n=15) sem tratamento na base. O sistema adesivo TransbondTM XT foi utilizado nos dois grupos seguindo o mesmo protocolo de colagem e respeitando as instruções do fabricante. Os corpos de prova foram armazenados em água destilada por 24 horas, e posteriormente submetidos ao teste de cisalhamento na máquina de ensaios universais (EMIC-DL2000). O IRA foi avaliado por dois examinadores calibrados utilizando lupa estereoscópica com aumento de 20 vezes. Resultado Na resistência ao cisalhamento o teste T-independente mostrou não haver diferença estatisticamente significante entre os grupos (p>0,05), ambos tiveram desempenho semelhante. O teste Wilcoxon foi utilizado nos valores obtidos no IRA revelando diferença estatística, sendo que os bráquetes TP® deixaram menos remanescente adesivo na superfície dental que os bráquetes Morelli®. Conclusão Bráquetes TP® apresentaram maior adesão ao sistema adesivo pois foi encontrado menor IRA nos mesmos, porém esta característica não reflete em melhora no desempenho clínico.

Abstract Objective The Primekote® (TP) polymer was incorporated to the of Orthodontic Bracket mesh base to improve bond strength and make it more efficient. The purpose of this study was to assess the shear bond strength and adhesive remnant index (ARI) of these brackets. Material and method The test sample consisted of thirty bovine incisors divided into 2 groups: with a group with TP® brackets (n=15), and a control group with Morelli® brackets (n=15) without Primekote® technology. The TransbondTM XT was used as adhesive system in both groups, following the same protocol and manufacturer’s instructions. Specimens were stored in distilled water for 24 hours and then submitted to shear bond strength test in a universal testing machine (EMIC DL2000). The assessment of ARI was performed under stereomicroscope by two calibrated examiners. Result No significant differences (p>0.05) in shear bond strength were found between the two groups according to the independent t-test. The Wilcoxon test was used to assess ARI data and statistical difference was found between Morelli® and TP® Nu-Edge brackets; the last one left less remaining adhesive on tooth surface. Conclusion TP® brackets had higher adherence to the adhesive system as shown by lower ARI scores, but this does not improve its clinical performance.

Orthodontic tooth movement (OTM) is a dynamic process of bone modeling involving osteoclast-driven resorption on the compression side. Consequently, to estimate the influence of various situations on tooth movement, experimental studies need to analyze this cell. Objectives The aim of this study was to test and validate a new method for evaluating osteoclastic activity stimulated by mechanical loading based on the fractal analysis of the periodontal ligament (PDL)-bone interface. Material and Methods The mandibular right first molars of 14 rabbits were tipped mesially by a coil spring exerting a constant force of 85 cN. To evaluate the actual influence of osteoclasts on fractal dimension of bone surface, alendronate (3 mg/Kg) was injected weekly in seven of those rabbits. After 21 days, the animals were killed and their jaws were processed for histological evaluation. Osteoclast counts and fractal analysis (by the box counting method) of the PDL-bone interface were performed in histological sections of the right and left sides of the mandible. Results An increase in the number of osteoclasts and in fractal dimension after OTM only happened when alendronate was not administered. Strong correlation was found between the number of osteoclasts and fractal dimension. Conclusions Our results suggest that osteoclastic activity leads to an increase in bone surface irregularity, which can be quantified by its fractal dimension. This makes fractal analysis by the box counting method a potential tool for the assessment of osteoclastic activity on bone surfaces in microscopic examination.

Aim: To compare 2 types of treatment for Class II malocclusion assessing mandibular behavior in subjects submitted to full orthodontic treatment with standard edgewise appliance and cervical headgear (Kloehn appliance) and those who used cervical headgear in the first period and with full orthodontic appliance in the second period. Methods: The sample consisted of 80 children treated with either cervical headgear combined with full fixed appliances (n=40, group 1), or with cervical headgear at first (n=40, group 2). In both groups, lateral cephalometric radiographs were compared with those made at the beginning of treatment, at its end and at 5-year post-retention phase, in order to quantify the cephalometric measures (8 angular and 3 linear), presenting the mandibular behavior in the antero-posterior and vertical directions. All patients were treated with no extraction and no use of Class II intermaxillary elastics during the full orthodontic treatment. Results: In both groups, the effective treatment of skeletal Class II malocclusion did not interfere in the direction and amount of growth of mandibular condyles and remodeling at the lower border, with no influence on the anti-clockwise rotation of the mandible. The mandibular growth also was observed after the orthodontic treatment, suggesting that it is influenced by genetic factors. Conclusions: These observations may lead to the speculation that growing patients with skeletal Class II malocclusion and low mandibular plane are conducive to a good treatment and long-term stability with one or two periods of treatment.

OBJETIVO: avaliar, por meio de imagens de tomografia computadorizada de feixe cônico (TCFC), as mudanças esqueléticas e dentárias, imediatas e após 6 meses de contenção, causadas pela expansão rápida da maxila (ERM) em pacientes com má oclusão de Classe II, divisão 1. MÉTODOS: dezessete crianças com má oclusão de Classe II, divisão 1, e deficiência transversal da maxila, foram submetidas a ERM, de acordo com o protocolo proposto por Haas. TCFC foram realizadas antes da ERM (T1), imediatamente após a fase ativa (T2) e após 6 meses de contenção (T3). Alterações anteroposteriores (SNA, SNB, ANB, overjet e RM) e verticais (N-ANS, ANS-Me, N-Me e overbite) foram analisadas. RESULTADOS: imediatamente após a ERM, enquanto a maxila se deslocou para frente, a mandíbula se movimentou para frente e para baixo, aumentando o overjet e diminuindo o overbite. Durante o período de contenção, a maxila retornou para posterior e a mandíbula deslocou em direção anterior, aumentando a altura facial anterior. CONCLUSÃO: a realização da ERM permitiu que a mandíbula se posicionasse mais anteriormente do que inferior durante o período de contenção, melhorando a relação molar de Classe II em 75% dos pacientes avaliados.

OBJECTIVE: To assess skeletal and dental changes immediately after rapid maxillary expansion (RME) in Class II Division 1 malocclusion patients and after a retention period, using cone beam computed tomography (CBCT) imaging. METHODS: Seventeen children with Class II, Division 1 malocclusion and maxillary skeletal transverse deficiency underwent RME following the Haas protocol. CBCT were taken before treatment (T1), at the end of the active expansion phase (T2) and after a retention period of 6 months (T3). The scanned images were measured anteroposteriorly (SNA, SNB, ANB, overjet and MR) and vertically (N-ANS, ANS-Me, N-Me and overbite). RESULTS: Significant differences were identified immediately after RME as the maxilla moved forward, the mandible moved downward, overjet increased and overbite decreased. During the retention period, the maxilla relapsed backwards and the mandible was displaced forward, leaving patients with an overall increase in anterior facial height. CONCLUSION: RME treatment allowed more anterior than inferior positioning of the mandible during the retention period, thus significantly improving Class II dental relationship in 75% of the patients evaluated.

INTRODUÇÃO: diferentes protocolos de irradiação por laser de baixa potência (LBP) têm sido testados para potencializar o movimento ortodôntico; entretanto, há resultados divergentes. Foi sugerido que seu efeito bioestimulador ocorre nas fases de proliferação e diferenciação celular, não agindo em estágios tardios. OBJETIVO: avaliar o efeito de dois protocolos de irradiação do LBP na movimentação ortodôntica: um com irradiações diárias e outro em que irradiações foram realizadas apenas nos períodos iniciais. MÉTODOS: trinta e seis ratos Wistar foram divididos em grupos controles (GC1, GC2 e GC3) e irradiados (GIr1, GIr2 e GIr3), de acordo com a presença de dispositivo ortodôntico, a presença de irradiação, o tipo de protocolo de irradiação e a data de eutanásia (3º ou 8º dia de experimento). Ao final dos períodos experimentais, foram realizadas mensurações da movimentação dentária, análise qualitativa das reações celulares e teciduais do periodonto e contagem de vasos sanguíneos no ligamento periodontal. RESULTADOS: a quantidade de movimentação não diferiu entre os grupos num mesmo tempo experimental (p < 0,05). A análise qualitativa revelou maior atividade absortiva nos grupos irradiados ao final de 7 dias, especialmente quando as irradiações foram diárias. Nos grupos irradiados diariamente, a contagem de vasos foi aumentada em relação aos animais isentos de dispositivo ortodôntico e de aplicações de LBP (p < 0,05). CONCLUSÃO: apesar de verificada angiogênese em certos grupos irradiados, os protocolos de irradiação testados não foram capazes de acelerar a movimentação dentária, e foi possível verificarem-se absorções radiculares.

INTRODUCTION: Different low-level laser (LLL) irradiation protocols have been tested to accelerate orthodontic tooth movement (OTM). Nevertheless, divergent results have been obtained. It was suggested that the stimulatory action of low level laser irradiation occurs during the proliferation and differentiation stages of bone cellular precursors, but not during later stages. OBJECTIVE: The purpose of this study was to determine the effect of two protocols of LLL irradiation on experimental tooth movement: One with daily irradiations and another with irradiations during the early stages. METHODS: Thirty-six rats were divided into control groups (CG1, CG2, CG3) and irradiated groups (IrG1, IrG2, IrG3) according to the presence of: experimental tooth movement, laser irradiation, type of laser irradiation protocol and date of euthanasia (3th or 8th day of experiment). At the end of experimental periods, a quantitative evaluation of the amount of OTM was made and the reactions of the periodontium were analyzed by describing cellular and tissue reactions and by counting blood vessels. RESULTS: The amount of OTM revealed no significant differences between groups in the same experimental period (p < 0.05). Qualitative analysis revealed the strongest resorption activity in irradiated groups after seven days, especially when using the daily irradiation protocol. There was a higher number of blood vessels in irradiated animals than in animals without orthodontic devices and without laser irradiation (p < 0.05). CONCLUSION: Moreover, angiogenesis was verified in some of the irradiated groups. The irradiation protocols tested were not able to accelerate OTM and root resorption was observed while they were applied.

OBJETIVO: o objetivo desse relato de caso clínico foi avaliar os resultados da correção da sobremordida exagerada por meio da técnica do arco segmentado. MÉTODOS: na primeira etapa do tratamento, utilizou-se essa técnica para intrusão dos incisivos e caninos. Em seguida, foram confeccionados e instalados uma barra transpalatina superior e um arco lingual inferior, ambos com fio de 0,051" de espessura, sendo associados ao arco facial ancorado, primeiramente, em tração occipital e, após a correção da chave de oclusão, foi modificada para tração parietal. RESULTADOS: os incisivos superiores apresentaram grande quantidade de intrusão com discreta inclinação palatal das raízes, conforme determinado no plano de tratamento. A resposta mandibular foi favorável, possibilitando o alcance de perfil mais harmonioso. Nas radiografias periapicais, observou-se suave arredondamento apical nas raízes dos incisivos, compatível com movimento de intrusão. CONCLUSÃO: os resultados clínicos conferem sucesso na abordagem da correção da sobremordida exagerada.

OBJECTIVE: The aim of this case report was to evaluate the results of deep overbite correction by the segmented arch technique. METHODS: The first stage of the treatment was performed with this technique to intrude incisors and canines. A maxillary transpalatal bar and a mandibular lingual arch using 0.051-in archwire were employed associated to a facial bow, anchored primarily with occipital pull and, after molar relationship correction, changed to high pull. RESULTS: Upper incisors presented a great amount of intrusion and some palatal root inclination as programmed in the treatment plan. The skeletal mandibular response was favorable to achieve profile balance. Periapical radiograph showed rounded apex of incisor roots, expected in any orthodontic intrusion movement. CONCLUSION: The clinical results present the successful approach to deep overbite malocclusion.

O Board Brasileiro de Ortodontia e Ortopedia Facial (BBO) é uma entidade de Certificação Nacional de padrão de excelência clínica no exercício da especialidade. O artigo, ora apresentado, traz o histórico da criação do BBO, sua estrutura e as fases que compõem a avaliação para obtenção da Certificação. Apresenta, ainda, o relato do primeiro exame aplicado no Brasil. O objetivo é multiplicar o conhecimento, entre os profissionais da área, sobre a importância da Certificação BBO como garantia do mais alto grau de qualidade no tratamento ortodôntico.

The Brazilian Board of Orthodontics and Facial Orthopedics (BBO) is the institution that certifies the standards of clinical excellence in the practice of this specialty. This article describes the history of BBO's creation and the examination structure and phases to obtain the BBO Certification. It also presents a detailed report of the first exam applied in Brazil. Its purpose is to expand the knowledge, among professionals in the area, about the importance of BBO Certification as assurance of the highest level of quality in orthodontic treatments.

INTRODUÇÃO: as principais utilizações do laser argônio na Ortodontia são a redução do tempo de polimerização durante a colagem ortodôntica e o aumento da resistência à cárie do esmalte dentário. OBJETIVO: o objetivo deste trabalho foi avaliar as alterações químicas e morfológicas do esmalte dentário humano tratado com laser argônio nos parâmetros da colagem ortodôntica. MÉTODOS: quinze primeiros pré-molares hígidos, extraídos por indicação ortodôntica, foram selecionados e seccionados no sentido do longo eixo em dois segmentos iguais. Uma metade de cada elemento dentário foi tratada e a outra permaneceu sem tratamento. Um total de 30 amostras foi analisado, criando o grupo laser (n = 15) e o grupo controle (n = 15). O tratamento foi feito com laser argônio com 250mW de potência por 5 segundos, com densidade de energia de 8J/cm². RESULTADOS: a análise de difração de raios X demonstrou duas fases em ambos os grupos, as fases apatita e monetita. A redução da fase monetita foi significativa após o tratamento com laser, sugerindo maior cristalinidade. A análise de Espectroscopia de Energia Dispersiva (EDS) indicou aumento na razão cálcio-fósforo no grupo laser, compatível com a diminuição da fase monetita. A morfologia superficial do esmalte dentário apresentou-se mais lisa após o tratamento com laser argônio. CONCLUSÕES: o aumento de cristalinidade e a lisura superficial do esmalte no grupo laser são fatores sugestivos de aumento de resistência à cárie no esmalte dentário.

INTRODUCTION: The main utilities of the argon laser in orthodontics are the high speed curing process in orthodontic bonding and the caries resistance promotion of the tooth enamel. OBJECTIVE: The objective of this study was to evaluate the chemical and morphological changes in the tooth enamel treated with the argon laser in the orthodontic bonding parameters. METHODS: Fifteen sound human first premolars, removed for orthodontic reason, were selected and sectioned across the long axis in two equal segments. One section of each tooth was treated and the other remained untreated. A total of thirty samples was analyzed, creating the laser group (n =15) and the control group (n =15). The treatment was done with 250 mW argon laser beam for 5 seconds, with energy density of 8 J/cm². RESULTS: The X-ray analysis demonstrated two different phases in both groups, the apatite and the monetite phases. The reduction of the monetite phase was significant following laser treatment, suggesting higher crystallinity. The EDS analysis showed an increase in the calcium-phosphorus ratio in the laser group, linked with the decrease of the monetite phase. CONCLUSIONS: The surface morphology was smoother after the laser exposure. The results of high crystallinity and superficial enamel smoothness in the laser group are suggestive of the caries resistance increase of the tooth enamel.

This study aimed to evaluate the cephalometric pattern of Class II Division 1 individuals with deep bite, and to determine possible correlations between dentoskeletal variables and deep bite. Comparisons were also made between genders and cases that were to be treated both with and without premolar extraction. A total of 70 lateral cephalograms were used, from both male (n = 35) and female (n = 35) individuals with an average age of 11.6 years, who simultaneously presented with ANB > 5º and overbite > 4 mm. Statistical analysis involved parametric (t-test) and non-parametric (Mann-Whitney) tests for independent samples, as well as the Spearman correlation test (p < 0.05). The values of Go-Me, Ar-Pog, PM-1 and PM-CMI were higher in males (p < 0.05). However, no significant differences were found among the averages of the cephalometric measurements when the sample was divided by treatment with and without extraction. Deep bite was positively correlated to the PM-1 and SNA measurements, and negatively correlated to the Go-Me, Ar-Pog, SNB and SNGoMe measurements. The main factors associated with the determination of deep bite in Angle's Class II Division 1 cases were: greater lower anterior dentoalveolar growth and/or lower incisor extrusion, horizontal growth pattern, maxillary protrusion and mandibular retrusion.

OBJECTIVE: The objective this work was to assess the friction coefficient between brackets and wires of different materials under conditions simulating the oral environment. MATERIAL AND METHODS: Stainless steel (SS) and titanium-molybdenum alloy (TMA) wires of 0.019x0.025-in diameter (American Orthodontics) and polycarbonate bracket (American Orthodontics), ceramic bracket (American Orthodontics), and metal bracket (3M Unitek) with slots of 0.022x0.030-in were used. The friction coefficient was assessed by means of mechanical traction with the system immersed in artificial saliva. The mean roughness of both wire surface and bracket slots was evaluated by using a surface profilometer. RESULTS: The system using TMA wire and polycarbonate bracket had the highest roughness (p<0.05). SS wire with ceramic bracket had the highest friction coefficient, whereas the use of metallic bracket yielded the lowest (p<0.05). However, it was observed a statistically significant difference in the system using TMA wire and ceramic bracket compared to that using TMA wire and polycarbonate bracket (p=0.038). CONCLUSIONS: Ceramic brackets in association with SS wire should be judiciously used, since this system showed a high friction coefficient.

Os objetivos deste estudo foram avaliar, por meio de tomografia computadorizada de feixe cônico (TCFC), a inclinação mésio-distal e vestíbulo-lingual dos incisivos permanente superiores e correlacionar os resultados com o posicionamento intra-ósseo do canino permanente superior na dentição mista. Foram selecionadas 30 crianças, entre 7 e 10 anos de idade, no período inicial de dentição mista, apresentando incisivos e primeiros molares permanentes erupcionados, caninos, primeiros e segundos molares decíduos presentes na cavidade bucal e caninos permanentes intra-ósseos. Foi realizada TCFC e com o software Dolphin Imaging®, versão 11.0 foi realizada a reconstrução em 3D destas imagens e feitas as medidas. A inclinação dos incisivos centrais e laterais superiores direito e esquerdo foi medida em relação ao plano sagital (angulação mésio-distal) e ao plano coronal (inclinação vestíbulo-lingual). A altura intra-óssea dos caninos superiores direito e esquerdo foi medida da ponta da cúspide ao plano axial. Para análise da correlação entre a angulação dos incisivos e altura dos caninos foi utilizado o teste de correlação de Pearson, ao nível de significância de 5%. Pode-se concluir que a posição intra-óssea dos caninos superiores sugere influência direta na inclinação dos incisivos superiores, principalmente nos incisivos laterais.

The aims of the present study were to evaluate the angulation and inclination of permanent maxillary incisors and to correlate the results to the intra-alveolar permanent maxillary canine position during mixed dentition, using cone beam computed tomography (CBCT). The subjects were 30 children aged 7 to 10 years in the inter-transitory period of mixed dentition (permanent incisors and first molars erupted; primary canines, first and second molars erupted; and permanent canines intraosseous). The CBCT scans were obtained and, using the Dolphin Imaging® software - version 11.0, 3D images were reconstructed and the measurements were performed. The angulation of the right and left lateral and central maxillary incisors was measured in relation to the sagittal plane and their inclination was measured in relation to the coronal plane. The intra-alveolar height of the right and left maxillary canines was measured from the cusp tip to the axial plane. Pearson's correlation at 5% significance level showed positive correlation between the canine height and the lateral incisor angulation. It was concluded that the intra-alveolar position of the maxillary canines has a direct influence on the angulation of maxillary incisors, especially the lateral incisors.

OBJETIVO: o objetivo dos autores desse estudo foi comparar o método de análise de dentição mista que utiliza tomografia computadorizada de feixe cônico para avaliar os diâmetros dos dentes intraósseos com os métodos de Moyers, Tanaka-Johnston e radiografias oblíquas em 45º. MÉTODOS: foram realizadas medidas, na arcada inferior, dos diâmetros mesiodistais dos incisivos permanentes irrompidos, nos modelos de gesso com auxílio de paquímetro digital e estimativa do tamanho de pré-molares e caninos permanentes ainda não irrompidos utilizando-se a tabela de Moyers e a fórmula de predição de Tanaka-Johnston. Nas radiografias oblíquas em 45º, caninos e pré-molares foram medidos utilizando-se o mesmo instrumento. Nas tomografias, as mesmas unidades dentárias foram aferidas por meio de ferramentas do programa Dolphin. RESULTADOS: a análise estatística revelou elevada concordância entre o método tomográfico e o radiográfico, e baixa concordância entre o tomográfico e os demais avaliados. CONCLUSÃO: a tomografia computadorizada de feixe cônico mostrou-se confiável para análise da dentição mista e apresenta algumas vantagens em relação aos métodos comparados: a observação e mensuração dos dentes intraósseos individualmente, com a possibilidade, contudo, de visualizá-los sob diferentes perspectivas e sem superposição de estruturas anatômicas.

OBJECTIVE: The aim of this study was to evaluate the method for mixed-dentition analysis using Cone-Beam Computed Tomography for assessing the diameter of intra-osseous teeth and compare the results with those obtained by Moyers, Tanaka-Johnston, and 45-degree oblique radiographs. METHODS: Measurements of mesial-distal diameters of erupted lower permanent incisors were made on plaster cast models by using a digital calliper, whereas assessment of the size of non-erupted permanent pre-molars and canines was performed by using Moyer's table and Tanaka-Johnston's prediction formula. For 45-degree oblique radiographs, both canines and pre-molars were measured by using the same instrument. For tomographs, the same dental units were gauged by means of Dolphin software resources. RESULTS: Statistic analysis revealed high agreement between tomographic and radiographic methods, and low agreement between tomographs and other methods being evaluated. CONCLUSION: Cone-Beam Computed Tomography was accurate for mixed-dentition analysis in addition to presenting some advantages over compared measurement methods: observation and measurement of intra-osseous teeth individually with the possibility, however, to view them from different prospects and without superimposition of anatomical structures.

A deficiência transversa da maxila é um fator agravante e complicador do tratamento ortodôntico em adultos. Sua correção ainda gera dúvidas e controvérsias entre clínicos e pesquisadores. O objetivo deste trabalho foi analisar e discutir fatores determinantes para o planejamento da expansão maxilar em adultos e adolescentes com maturação esquelética avançada. Ausências dentárias múltiplas, grandes inclinações dentoalveolares para vestibular, recessão gengival, perda óssea alveolar e mobilidade dos dentes posterossuperiores contraindicam a realização de expansão rápida da maxila em indivíduos adultos ou com maturação esquelética avançada. No entanto, esses fatores não devem ser considerados isoladamente para a escolha do método de expansão palatal nesses pacientes. Nessas situações, a Expansão Rápida da Maxila Assistida Cirurgicamente (ERMAC) pode ser uma opção, entretanto, a escolha por essa técnica deve basear-se principalmente na idade do paciente, no grau de maturação esquelética, na localização da deficiência transversa da maxila e nas estruturas anatômicas que oferecem maior resistência à expansão maxilar. O Hyrax é o aparelho mais indicado para indivíduos que vão se submeter à ERMAC.

The transverse maxillary deficiency is a complication factor in adults' orthodontic treatment. Its correction still generates doubts and controversies between clinicians and researchers. The aim of this paper is to discuss the determinative factors in planning maxillary expansion in adults and adolescents with advanced skeletal maturation. Multiple dental absences, several dentoalveolar buccal inclination, gingival recession, alveolar bone loss and mobility of posterosuperior teeth contraindicate the rapid maxillary expansion in adults or patients with advanced skeletal maturation. However, these factors should not be considered separately when choosing the method for palatal expansion in adults. In these situations Surgically Assisted Rapid Maxillary Expansion (SARME) can be an option. And the choice of the surgical technique (SARME) should focus mainly the patient's age, grade of skeletal maturation, anatomical structures that offer more resistance to the maxillary expansion and location of the palatal constriction. Hyrax is the expander appliance more indicated for patients that will be submitted to SARME.

The purpose of the present study was to evaluate the shear bond strength to enamel and the adhesive remnant index (ARI) of both metallic and polycarbonate brackets bonded under different conditions. Ninety bovine permanent mandibular incisors were embedded in acrylic resin using PVC rings as molds and assigned to 6 groups (n=15). In Groups 1 (control) and 3, metallic and polycarbonate orthodontic brackets were, respectively, bonded to the enamel surfaces using Transbond XT composite according to the manufacturer's recommendations. In Groups 2 and 4, both types of brackets were bonded to enamel with Transbond XT composite, but XT primer was replaced by the OrthoPrimer agent. In Groups 5 and 6, the polycarbonate bracket bases were sandblasted with 50-mm aluminum-oxide particle stream and bonded to the enamel surfaces prepared under the same conditions described in Groups 3 and 4, respectively. After bonding, the specimens were stored in distilled water at 37ºC for 24 hours and then submitted to shear bond strength test at a crosshead speed of 0.5 mm/min. The results (MPa) showed no statistically significant difference between Groups 4 and 6 (p>0.05). Likewise, no statistically significant differences (p>0.05) were found among Groups 1, 2, and 5, although their results were significantly lower than those of Groups 4 and 6 (p<0.05). Group 3 had statistically significant lower bond strength than Groups 2, 4, and 6, but no statistically significant differences were found on comparison to Groups 1 and 5. A larger number of fractures at the bracket/composite interface were evidenced by the ARI scores. OrthoPrimer bonding agent yielded higher bond strength in the groups using either conventional or sandblasted polycarbonate brackets, which was not observed in the groups using metallic brackets.