Analysis of mesiodistal angulations of preadjusted brackets.

Manufacturers offer various prescriptions of preadjusted brackets for use in the "straight-wire" orthodontic technique. However, the need to incorporate bends in the rectangular wires during orthodontic finishing has led to concerns regarding the type of prescription chosen and the credibility of information provided by the manufacturer. The aim of this study was to compare the slot angulations of Roth prescription preadjusted metallic brackets for the maxillary left central incisor and maxillary left canine. For each tooth type, 10 brackets of three commercial brands (GAC, Forestadent and Morelli) were selected. Two individual metal matrices for brackets and tooth positioning were made for each group of teeth. Captured images were obtained by standardized ortho-radial photography with a digital camera. Images were exported and analyzed with the Image J software package. One-way ANOVA and Tukey statistical analyses were performed at the 5% significance level. For brackets of the maxillary left central incisor, differences in mean angulation were observed between the Morelli and GAC groups (p < 0.01) and between the Forestadent and GAC groups (p < 0.01). For brackets of the maxillary left canine, differences in mean angulation were found between the Morelli and GAC groups (p < 0.01) and between the Morelli and Forestadent groups (p < 0.05). In conclusion, despite their same prescription name, the different brands exhibited significantly different angulation measurements.

Avaliação histopatológica da luxação extrusiva em molares de ratos / Histopathological evaluation of extrusive luxation in rat molars

Neste estudo foram avaliados os eventos biopatológicos decorrentes da luxação extrusiva em molares de ratos por meio de análise histopatológica, estabelecendo a respectiva cronologia do processo tecidual. Cento e vinte ratos machos Wistar foram utilizados e o traumatismo dentoalveolar (luxação extrusiva) foi aplicado na face distal do primeiro molar superior direito. Sessenta animais foram submetidos à luxação extrusiva e sessenta animais serviram como controle. As raízes mésio e distovestibular, o septo interradicular e o tecido pulpar foram avaliados 1, 3, 5, 7, 14 e 28 dias após a luxação por meio de análise microscópica, com cortes de três micrômetros de espessura. Nos grupos em que os animais foram submetidos à eutanásia após 3 e 28 dias os eventos biopatológicos (reabsorção radicular externa, formação de áreas hialinas, presença de infiltrado inflamatório e de células gigantes multinucleadas) apresentaram-se mais exuberantes nas estruturas anatômicas analisadas. De um modo geral, a cronologia do processo de reparo também foi estabelecida após a luxação: início (um dia pós-trauma); pico do processo inflamatório (três dias); início do processo de reparo (cinco dias); consolidação do processo de reparo (sete dias); neoformação óssea (14 dias) e início do processo de necrose pulpar (28 dias)...

This study evaluated the events biopathological arising from extrusive luxation in rat molars through histopathologic analysis , establishing the chronology of the repair process. One hundred and twenty male Wistar rats were used and dentoalveolar trauma (extrusive luxation) was applied to the distal surface of the maxillary right first molar. Sixty animals were extrusive luxation and sixty animals served as controls. The mesial root and distobuccal , the interradicular septum and the pulp tissue were assessed 1, 3 , 5, 7 , 14 and 28 days after the trauma by microscopic analysis of sections with three micrometers. In the groups in which animals were euthanized after 3 and 28 days the biopathological events (external root resorption, formation of hyaline areas, inflammatory infiltrate and giant cells) were more exuberant in the anatomical structures analyzed. Generally , the timing of the repair process has also been established after the luxation: early (one day post-trauma); peak of inflammation (three days); initial repair process (five days); consolidation of repair (seven days), bone formation (14 days ) and start the process of pulp necrosis (28 days)...

Avaliação histopatológica da luxação extrusiva em molares de ratos / Histopathological evaluation of extrusive luxation in rat molars

Neste estudo foram avaliados os eventos biopatológicos decorrentes da luxação extrusiva em molares de ratos por meio de análise histopatológica, estabelecendo a respectiva cronologia do processo tecidual. Cento e vinte ratos machos Wistar foram utilizados e o traumatismo dentoalveolar (luxação extrusiva) foi aplicado na face distal do primeiro molar superior direito. Sessenta animais foram submetidos à luxação extrusiva e sessenta animais serviram como controle. As raízes mésio e distovestibular, o septo interradicular e o tecido pulpar foram avaliados 1, 3, 5, 7, 14 e 28 dias após a luxação por meio de análise microscópica, com cortes de três micrômetros de espessura. Nos grupos em que os animais foram submetidos à eutanásia após 3 e 28 dias os eventos biopatológicos (reabsorção radicular externa, formação de áreas hialinas, presença de infiltrado inflamatório e de células gigantes multinucleadas) apresentaram-se mais exuberantes nas estruturas anatômicas analisadas. De um modo geral, a cronologia do processo de reparo também foi estabelecida após a luxação: início (um dia pós-trauma); pico do processo inflamatório (três dias); início do processo de reparo (cinco dias); consolidação do processo de reparo (sete dias); neoformação óssea (14 dias) e início do processo de necrose pulpar (28 dias)

This study evaluated the events biopathological arising from extrusive luxation in rat molars through histopathologic analysis , establishing the chronology of the repair process. One hundred and twenty male Wistar rats were used and dentoalveolar trauma (extrusive luxation) was applied to the distal surface of the maxillary right first molar. Sixty animals were extrusive luxation and sixty animals served as controls. The mesial root and distobuccal , the interradicular septum and the pulp tissue were assessed 1, 3 , 5, 7 , 14 and 28 days after the trauma by microscopic analysis of sections with three micrometers. In the groups in which animals were euthanized after 3 and 28 days the biopathological events (external root resorption, formation of hyaline areas, inflammatory infiltrate and giant cells) were more exuberant in the anatomical structures analyzed. Generally , the timing of the repair process has also been established after the luxation: early (one day post-trauma); peak of inflammation (three days); initial repair process (five days); consolidation of repair (seven days), bone formation (14 days ) and start the process of pulp necrosis (28 days)

Interceptive approach to treatment of impacted maxillary canines.

Impaction of maxillary canines can be prevented by early intervention in the mixed dentition phase after the correct diagnosis of malocclusion, reducing the complexity of the treatment. This article reports the case of a 10-year-old patient who possessed impacted maxillary canines and, after early extraction of primary canines, had reestablished favorable permanent successors' eruption axis. This 5-year radiographic follow-up study with panoramic radiography shows that this can be used in practice and that an effective control strategy ensures the accuracy in the inclination of the impacted canines. Treatment success is related to early diagnosis and strategic interceptive treatment choice.

Microscopic evaluation of induced tooth movement in traumatized teeth: an experimental study in rats.

The clinical management of orthodontic patients with dental trauma before or during the treatment is mainly founded on clinical experience, expert opinions, and individual case reports. It is proposed in the literature that teeth sustaining mild trauma with minor damage to the periodontium (e.g. subluxation) should be followed for a period of time before being subjected to orthodontic forces. A minimum period of 3 months has been proposed. In this study, we used an animal model to investigate whether shorter observation periods could be established in case of mild trauma. The periradicular region of rat molars was examined microscopically to determine the biological events of tooth movement started 15 and 30 days after intentional subluxation using an experimental method to induce dentoalveolar trauma. Thirty adult male Wistar rats were assigned to 6 groups (n = 5): Group 1 (control - no trauma/orthodontic movement); Group 2: the animals received an orthodontic device and were sacrificed after 7 days; Groups 3 and 4: dentoalveolar trauma (subluxation) was experimentally induced by the application of an axial force of 900 cN on the occlusal surface of the maxillary right first molar, and the animals were sacrificed after 22 and 37 days, respectively; and Groups 5 and 6: 15 and 30 days, respectively, after force application, an orthodontic device was installed and the rats were sacrificed 7 days later. In G5 and G6, the periodontal ligament and pulp tissue were rich in cellular elements and blood vessels, the alveolar bone was preserved, and the root surface presented only very small areas of surface resorption (cementum), maintaining the characteristics of normality. In conclusion, the microscopic alterations in the gingival and periodontal tissues in response to an experimentally induced mild dentoalveolar trauma simulating subluxation were not sufficient to contraindicate starting the orthodontic movement 15 and 30 days after trauma.

Spectophotometric evaluation of color changes of esthetic brackets stored in potentially staining solutions

The purpose of this study was to evaluate, in vitro, the chromatic behavior of esthetic brackets stored in potentially staining solutions. The sample were divided into four groups according to the commercial brand and stored in four different solutions (distilled water, cola soda, coffee and mouthrinse) at 37°C for 14 days. Possible color changes measured according to the CIE L*a*b* color system with a spectrophotometer at five intervals of time after storage. The statistical analysis was carried out using ANOVA to 1%, TukeyÆs tests and decomposition of interactions with a significance level of 5%.The color changes were dependent on the solution, storage time and the brand of brackets. The largest color changes were observed in the G3, followed by G2. The esthetic brackets do not present satisfactory and stable chromatic behavior

Avaliação espectrofotométrica das alterações cromáticas de bráquetes estéticos armazenados em soluções potencialmente corantes / Spectrophotomeric evaluation of chromatic changes of the esthetic brackets stored in potentially staining solutions

Objetivos. O presente estudo avaliou o comportamento cromático de bráquetes estéticos de diferentes materiais armazenados em soluções potencialmente corantes (água destilada, refrigerante, café e enxaguatório contendo álcool). Métodos. As amostras foram divididas em quatro grupos de acordo com a marca comercial e armazenadas em quatro tipos de soluções (água destilada, refrigerante, café e enxaguatório contendo álcool) a 37°C durante 14 dias. As possíveis alterações de cor foram mensuradas por meio de um espectrofotômetro de reflectância em cinco intervalos de tempo após o armazenamento. As alterações de cor foram registradas de acordo com o sistema CIE L*a*b* e a análise estatística foi conduzida empregando-se ANOVA a 1%, aplicação dos testes de Tukey e decomposição das interações com nível de significância a 5%. Resultados. As alterações de cor foram dependentes da solução, tempo de armazenamento e marca dos bráquetes. As maiores alterações de cor foram observadas nos bráquetes Invu™, seguido pelo Silkon Plus™, Composite® e Transcend™, com diferenças estatisticamente significantes. Significância. As soluções potencialmente corantes podem interferir na aparência dos bráquetes estéticos. Portanto, quando estes acessórios são utilizados, os pacientes devem ser informados sobre a possibilidade das alterações de cor ao longo do tempo e da necessidade de redução do consumo de produtos com potencial corante

Objectives. The aim of this study was evaluated the chromatic behavior of the esthetic brackets of different materials exposure at the immersion in potentially staining solutions (distilled water, soda, coffe and mouthrinse with alcohol). Methods. The sample were divided in four groups of agreement with the commercial brand and stored in four types of the solutions (distilled water, soda to the base of cola, cofee and mouthrinse containing alcohol) at 37°C for 14 days. Color changes were measured by a reflection spectrophotometer in five time intervals after storage. The color changes were recorded according to the CIE L*a*b* system and the statistical analysis were carried out using ANOVA to 1%, application of the tests of Tukey and the decomposition of interactions with a significance level of 5%. Results.The color changes were dependent on the solution, storage time and the brand of brackets. The largest color changes were observed in the Invu™, followed by Silkon Plus™, Composite® and Transcend™ brackets, with statistic significance. Significance. The potentially staining solutions can interfere in the desirable appearance of esthetic brackets. Thus, when these attachments are used, the patient should be informed about possible color changes in the long-therm, and should reduce the consumption of potentially staining produtos