Development and Evaluation of a New Orthodontic Ligature: Frictional Force Analysis.

OBJECTIVE: To evaluate and compare the friction of different ligature modes used in orthodontics, and to propose a new ligature model for conventional brackets ("H low-friction orthodontic ligature). MATERIALS AND METHODS: Samples were randomly divided into seven experimental groups: (1) resin H ligature (H3D), designed by the authors of this study and produced in a 3D printer, with conventional bracket; (2) metal H ligature (HFM), with conventional bracket; (3) passive self-ligating bracket (SLP); (4) "8" low-friction unconventional elastic (LT8), with conventional bracket; (5) loose conventional metal ligature (MLS), with conventional bracket; (6) conventional metal ligature fully tightened (MLT), with conventional bracket; (7) conventional elastic ligature (CEL), with conventional bracket-control. All samples were subjected to mechanical static friction testing using the EMIC DL 2000 universal testing machine. STATISTICAL ANALYSIS: To assess the normality requirement, the Shapiro-Wilk test was used, which showed a non-normal distribution for the means of the groups (p < 0.05). Therefore, statistical tests were performed to assess the existence of statistically significant differences between the groups through the Kruskal-Wallis, followed by Dunn's test, pairwise comparison, p < 0.05. RESULTS: The results obtained showed lower friction values for HFM (0.002 kgf), SLP (0.003 kgf), and LT8 (0.004 kgf)-these did not differ statistically from each other. These were followed by H3D (0.020 kgf), MLS (0.049 kgf), CEL (0.12 kgf), and, finally, MLT (0.21 kgf). CONCLUSION: The lowest friction value was found for the metal H ligature, similar to the self-ligating bracket and the "8" low-friction unconventional elastic. The resin H ligature presented intermediate friction values and the highest friction force was found for the MLT group.

Is Identity Essentialism a Fundamental Feature of Human Cognition?

The present research examines whether identity essentialism, an important component of psychological essentialism, is a fundamental feature of human cognition. Across three studies (Ntotal = 1723), we report evidence that essentialist intuitions about the identity of kinds are culturally dependent, demographically variable, and easily malleable. The first study considered essentialist intuitions in 10 different countries spread across four continents. Participants were presented with two scenarios meant to elicit essentialist intuitions. Their answers suggest that essentialist intuitions vary dramatically across cultures. Furthermore, these intuitions were found to vary with gender, education, and across eliciting stimuli. The second study further examined whether essentialist intuitions are stable across different kinds of eliciting stimuli. Participants were presented with two different scenarios meant to elicit essentialist intuitions-the "discovery" and "transformation" scenarios. Their answers suggest that the nature of the eliciting stimuli influences whether or not people report essentialist intuitions. Finally, the third study demonstrates that essentialist intuitions are susceptible to framing effects. Keeping the eliciting stimulus (i.e., the scenario) constant, we show that the formulation of the question eliciting a judgment influences whether or not people have essentialist intuitions. Implications of these findings for identity essentialism and psychological essentialism, in general, are discussed.

Tratamento ortodôntico de paciente portador de síndrome de Treacher Collins ­ relato de caso / Orthodontic treatment of a patient with Treacher Collins syndrome ­ case report

Resumo Este trabalho é uma descrição de um caso clínico de paciente portador de Síndrome de Treacher Collins (STC). O paciente em questão é menor de idade e foi submetido a tratamento ortodôntico interceptivo de má oclusão de classe II, característica da síndrome devido à retrognatia, no Centro de Atenção e Pesquisa em Anomalia Craniofacial (CEAPAC), Cascavel ­ PR. As disostoses faciais são um conjunto de anomalias raras do esqueleto craniofacial, a mais comumente descrita é a STC, que é uma doença rara, sem predisposição por sexo ou raça. Os sintomas e a severidade desta síndrome diferem de indivíduo para indivíduo, mesmo entre membros da mesma família. Suas características comuns são as anormalidades dos pavilhões auriculares, hipoplasia dos ossos da face, obliquidade antimongolóide das fendas palpebrais com coloboma palpebral inferior e fissura palatina e o principal problema anatômico é a hipoplasia do terço médio da face e o hipodesenvolvimento da mandíbula e mento, o que leva o paciente portador desta síndrome apresentar por suas características faciais uma má oclusão de classe II muitas vezes associadas à mordida aberta, além de outros problemas orais como, por exemplo, as patologia das glândulas salivares, respiração bucal e apinhamento dentário. O tratamento ortodôntico intercepetivo do menor, embora após terminado tenha permanecido com má oclusão de classe II, obteve mudanças em parâmetros cefalométricos e faciais do paciente.(AU)

Abstract This work is a description of a clinical case of a patient with Treacher Collins Syndrome (CTS). The patient in question is younger and underwent interceptive orthodontic treatment of class II malocclusion, characteristic of the syndrome due to retrognathia, at the Center for Attention and Research in Craniofacial Anomaly (CEAPAC), Cascavel ­ PR. Facial dysostosis is a set of rare anomalies of the craniofacial skeleton, the most commonly described being CTS, it is a rare disease, without predisposition by sex or race. The symptoms and severity of this syndrome differ from individual to individual, even among members of the same family. Its common features are auricular pavilion abnormalities, facial bone hypoplasia, antimongoloid obliquity of the palpebral fissures with lower palpebral coloboma and cleft palate, and the main anatomical problem is hypoplasia of the middle third of the face and hypodevelopment of the mandible and chin, which Due to their facial characteristics, patients with this syndrome have a Class II malocclusion, often associated with an open bite, in addition to other oral problems such as salivary gland pathology, mouth breathing and dental crowding. The minor's interceptive orthodontic treatment, although after it ended, he remained with class II malocclusion, resulted in changes in the patient's cephalometric and facial parameters.(AU)

Auricular acupuncture in TMD - A sham-controlled, randomized, clinical trial.

This study evaluated the effect of auricular acupuncture (AA) on physical (PA) and emotional (EA) aspects of patients with temporomandibular disorders (TMDs) and compared the effect of AA with those of Sham and occlusal splints (OS). In accordance with the CONSORT guidelines, patients with TMDs were evaluated by axes I and II of the RDC-TMD. The patients were allocated among three groups: OS, Sham and AA; and followed for 8 weeks. Both intragroup and intergroup evaluation for quantitative variables were analyzed with ANOVA, one-way, followed by the Tukey test. Qualitative variables were analyzed with the Kruskal-Wallis, and Dunn tests (intergroup evaluation) and for intragroup analyses, the Friedman and Wilcoxon tests were applied. At the end of the experiment, the chi-squared test was applied to compare the three groups with respect to the number of variables that had shown improved scores. The adopted level of significance for all tests was α = 5%. Intragroup analysis showed that, in the Sham group, no improvement in performance was seen in either EA and significant was improvements in 5 variables for 9 for PA, while in the AA group, significant improvements were observed in 2 variables for EA and in 9 for PA. In the OS group at the end of this study, significant improvements were observed in 8 and 8 variables for EA and PA, respectively. The analysis of therapies used revealed that the number of variables exhibiting significantly improved outcomes after treatment was similar between the AA and OS groups, whereas the sham group showed statistically significant differences when compared with the other two groups. In conclusion, this study demonstrated that AA applied at a specific TMJ ear point was able to bring about improvements in patients with TMDs, with outcomes similar to those in patients treated with an OS. CLINICAL TRIAL REGISTRATION: RBR-69ynnw (Brazilian Registry of Clinical Trials).

Osmotic Method for Calculating Surface Pressure of Monolayers in Molecular Dynamics Simulations.

Surface pressure is a fundamental thermodynamic property related to the activity of molecules at interfaces. In molecular simulations, it is typically calculated from its definition: the difference between the surface tension of the air-water and air-surfactant interfaces. In this Letter, we show how to connect the surface pressure with a two-dimensional osmotic pressure and how to take advantage of this analogy to obtain a practical method of calculating surface pressure-area isotherms in molecular simulation. As a proof-of-concept, compression curves of zwitterionic and ionic surfactant monolayers were obtained using the osmotic approach and the curves were compared with the ones from the traditional pressure tensor-based scheme. The results shown an excellent agreement between both alternatives. Advantageously, the osmotic approach is simple to use and allows to obtain the surface pressure-area isotherm on the fly with a single simulation using equilibration stages.

Computer Simulations of Deep Eutectic Solvents: Challenges, Solutions, and Perspectives.

Deep eutectic solvents (DESs) are one of the most rapidly evolving types of solvents, appearing in a broad range of applications, such as nanotechnology, electrochemistry, biomass transformation, pharmaceuticals, membrane technology, biocomposite development, modern 3D-printing, and many others. The range of their applicability continues to expand, which demands the development of new DESs with improved properties. To do so requires an understanding of the fundamental relationship between the structure and properties of DESs. Computer simulation and machine learning techniques provide a fruitful approach as they can predict and reveal physical mechanisms and readily be linked to experiments. This review is devoted to the computational research of DESs and describes technical features of DES simulations and the corresponding perspectives on various DES applications. The aim is to demonstrate the current frontiers of computational research of DESs and discuss future perspectives.

Thermal and mechanical characterization of thermoplastic orthodontic aligners discs after molding process.

Polymeric aesthetic aligners were introduced in orthodontics as an innovative alternative to fixed appliances, however, their compositions and the thermal molding process may influence the biomechanical characteristics of these aligners. In this study four different clear aligner brands were used, ACE 035 Essix, C + Essix, Crystal 0.75 and Crystal 1.0, whose aim was to identify the thermal-processing influence on the mechanical and physicochemical properties of these materials, and to suggest a orthodontic sequence of wear for these appliances to achieve more effective treatment results. For the tensile tests the sample size calculation was based on probability distributions from the F test. The effect size used was 0.3, type 1 error of 0.05. Statistical Yield strength and Young's Modulus results were evaluated using the Shapiro-Wilk test. The groups were compared using the parametric test of analysis of variance, with Tukey post-test. Differences were statistically considered at the p < 0.05. The Infrared spectroscopy analysis showed no changes in the samples' chemical structure after thermal-processing. However, in the polypropylene aligner, differences were verified in the region attributed to the crystalline phase. Differential Scanning Calorimetry analysis for the same sample showed a crystallinity fraction decrease due to relaxation between polymer chains after molding. In the tensile tests evaluated, the tensile strength and 'Young's modulus presented higher values for aligners containing 100% polyethylene terephthalate glycol. Performing an analogy exercise of the properties of orthodontic wires used in conventional fixed appliances and, relating them to orthodontic plastics, aligners composed of different materials and/or thicknesses could be used in increasing sequence in terms of the modulus of elasticity, starting with C+, which has a lower elastic modulus value, using the ACE 035 as an intermediate and finishing with the Crystal 0.75 and 1.0, providing the desired stiffness to the aligners for the final phase.

Fine-Tuning the Polarizable CL&Pol Force Field for the Deep Eutectic Solvent Ethaline.

Polarizable force fields are gradually becoming a common choice for ionic soft matter, in particular, for molecular dynamics (MD) simulations of ionic liquids (ILs) and deep eutectic solvents (DESs). The CL&Pol force field introduced in 2019 is the first general, transferable, and polarizable force field for MD simulations of different types of DESs. The original formulation contains, however, some problems that appear in simulations of ethaline and may also have a broader impact. First, the originally proposed atomic diameter parameters are unbalanced, resulting in too weak interactions between the chlorides and the hydroxyl groups of the ethylene glycol molecules. This, in turn, causes an artificial phase separation in long simulations. Second, there is an overpolarization of chlorides due to strong induced dipoles that give rise to the presence of peaks and antipeaks at very low q-vector values (2.4 nm-1) in the partial components of the structure factors. In physical terms, this is equivalent to overestimated spatial nanoscale heterogeneity. To correct these problems, we adjusted the chloride-hydroxyl radial distribution functions against ab initio data and then extended the use of the Tang-Toennis damping function for the chlorides' induced dipoles. These adjustments correct the problems without losing the robustness of the CL&Pol force field. The results were also compared with the nonpolarizable version, the CL&P force field. We expect that the corrections will facilitate reliable use of the CL&Pol force field for other types of DESs.

Strengthening Cellulose Nanopaper via Deep Eutectic Solvent and Ultrasound-Induced Surface Disordering of Nanofibers.

The route for the preparation of cellulose nanofiber dispersions from bacterial cellulose using ethylene glycol- or glycerol-based deep eutectic solvents (DES) is demonstrated. Choline chloride was used as a hydrogen bond acceptor and the effect of the combined influence of DES treatment and ultrasound on the thermal and mechanical properties of bacterial cellulose nanofibers (BC-NFs) is demonstrated. It was found that the maximal Young's modulus (9.2 GPa) is achieved for samples prepared using a combination of ethylene glycol-based DES and ultrasound treatment. Samples prepared with glycerol-based DES combined with ultrasound exhibit the maximal strength (132 MPa). Results on the mechanical properties are discussed based on the structural investigations that were performed using FTIR, Raman, WAXD, SEM and AFM measurements, as well as the determination of the degree of polymerization and the density of BC-NF packing during drying with the formation of paper. We propose that the disordering of the BC-NF surface structure along with the preservation of high crystallinity bulk are the key factors leading to the improved mechanical and thermal characteristics of prepared BC-NF-based papers.

Tratamento ortodôntico em paciente com queimadura facial ­ relato de caso / Orthodontic treatment in patient with facial burn injury ­ case report

Resumo Inúmeras variáveis são consideradas em uma oclusão normal, uma delas é a homeostasia da musculatura facial e sua harmonia com os ossos e dentes. Diversos fatores podem levar a alterações na funcionalidade muscular. Um exemplo é a queimadura facial, na qual é comum a formação de cicatrizes hipertróficas que provocam disfunção nas estruturas musculares e impactam no crescimento facial e no desenvolvimento da dentição. Paciente K.R.S, sexo feminino, 15 anos, procurou tratamento no Centro de Atenção e Pesquisa de Anomalias Craniofaciais (CEAPAC) com queixa de "dentes tortos". Durante anamnese relatou que quando criança sofreu um acidente doméstico que acarretou queimaduras na face e parte do corpo. A paciente era portadora de má oclusão de Classe I de Angle e lingualização dos incisivos superiores e inferiores. Observou-se atresia das arcadas dentárias e apinhamento moderado. Realizou-se a expansão rápida da maxila e expansão dentária inferior com a placa lábio ativa, seguida de alinhamento e nivelamento dos dentes com aparelho fixo. Na fase de contenção utilizaram-se placas de Hawley (superior e inferior), além de uma contenção fixa inferior. Os tratamentos de expansão das arcadas e alinhamento se mostraram viáveis e previsíveis. Entretanto a estabilidade tem prognóstico duvidoso, o que levou os autores a indicarem o uso das contenções por tempo indeterminado.(AU)

Abstract Numerous variables are considered in a normal occlusion, one of those is the homeostasis of the facial musculature and its harmony with bones and teeth. Several factors can lead to change in muscle functionality. An example is the facial burn injury in which it is common formation of hypertrophic scars that cause muscle structures dysfunction and impact on facial growth and dentition development. Patient K.R.S, 15-years-old, female, sought treatment at the Center for Attention and Research of Craniofacial Anomalies (CEAPAC) complaining of "crooked teeth". She reported during anamnesis that when she was a child, she suffered a domestic accident which caused facial, and body burn injury. The patient had Angle Class I malocclusion and upper and lower incisor lingualization. Dental arch atresia and moderate crowding were observed. Rapid maxillary expansion and lower dental expansion were performed with the lip bumper, followed by teeth alignment and leveling with a fixed appliance. In the retainment phase, Hawley plates (upper and lower) were used in addition to a fixed lower retainer. The treatment of arch expansion and alignment proved to be viable and predictable, however, the stability has a dubious prognosis, which led the authors to indicate the use of retainers indefinitely. (AU)

For Whom Does Determinism Undermine Moral Responsibility? Surveying the Conditions for Free Will Across Cultures.

Philosophers have long debated whether, if determinism is true, we should hold people morally responsible for their actions since in a deterministic universe, people are arguably not the ultimate source of their actions nor could they have done otherwise if initial conditions and the laws of nature are held fixed. To reveal how non-philosophers ordinarily reason about the conditions for free will, we conducted a cross-cultural and cross-linguistic survey (N = 5,268) spanning twenty countries and sixteen languages. Overall, participants tended to ascribe moral responsibility whether the perpetrator lacked sourcehood or alternate possibilities. However, for American, European, and Middle Eastern participants, being the ultimate source of one's actions promoted perceptions of free will and control as well as ascriptions of blame and punishment. By contrast, being the source of one's actions was not particularly salient to Asian participants. Finally, across cultures, participants exhibiting greater cognitive reflection were more likely to view free will as incompatible with causal determinism. We discuss these findings in light of documented cultural differences in the tendency toward dispositional versus situational attributions.

Aged Translucent Aesthetic Zirconia: Bond Strength Analysis.

OBJECTIVE: This study evaluates the bond strength of two compositions of aesthetic translucent zirconia (TZ). MATERIALS AND METHODS: For this evaluation, test specimens were prepared from ICE Zirkon TZ and Prettau Anterior zirconia (PAZ) that were stored in distilled water at 37°C for two time periods: T1 (24 h) and T2 (90 days) to simulate aging. Two factors were evaluated for the samples-ceramic and aging time. The samples were subjected to tests of microshear strength and fracture type and were evaluated using scanning electron microscopy. RESULTS: The results were analyzed using the D'Agostino test, analysis of variance, and Tukey's test (p < 0.01). Statistically significant differences were observed for ceramic type and aging time. CONCLUSION: The results showed that PAZ provides significantly superior performance to TZ at the two aging times evaluated.

Effects of low-power laser auriculotherapy on the physical and emotional aspects in patients with temporomandibular disorders: A blind, randomized, controlled clinical trial.

OBJECTIVES: This study evaluated the effects of low-power laser auriculotherapy (LA) on the physical and emotional symptoms of patients with temporomandibular disorders (TMDs), in comparison with occlusal splints (OS). DESIGN: Randomized, blinded, prospective, non-inferiority clinical trial. INTERVENTIONS: The patients received OS (control group) or LA (experimental group). MAIN OUTCOME MEASURES: Following the Consolidated Standards of Reporting Trials (CONSORT) guidelines, patients with TMD were evaluated by using axes I and II of the Research Diagnostic Criteria for RDC-TMD. Both intra- and intergroup quantitative variables were analyzed with ANOVA (p < 0.05), while qualitative variables were analyzed with the Kruskal-Wallis (intergroup evaluations; p < 0.05) or Mann-Whitney tests (intragroup analyses; p < 0.05). RESULTS: OS improved five physical symptoms of TMD (pain in the right temporal muscle, right and left masseter muscles, left joint, and left intraoral region), while LA improved six (jaw functioning; pain in left masseter muscle, right and left joints, and right and left intraoral regions). Similarly, OS improved seven emotional symptoms (degree of depression, degree of non-specific physical symptoms, excluding pain, degree of non-specific physical symptoms including pain, average pain value in the past 6 months, presence of depression, intensity and characteristics of pain, non-specific physical symptoms including pain), while LA improved five (degree of non-specific physical symptoms including pain, presence of depression, intensity and characteristics of pain, non-specific physical symptoms including pain, non-specific physical symptoms excluding pain). CONCLUSION: LA improved the physical and emotional symptoms of TMD, with results similar to OS. CLINICAL RELEVANCE: For the physical and emotional symptoms associated with TMD, LA showed similar outcomes as OS.

Bond strength and marginal microleakage in restorations photopolymerized with LED and halogen light associated with three application modes of a universal adhesive system: in vitro study / Resistência de união e da microinfiltração marginal em restaurações fotopolimerizadas com LED e luz halógena associadas a três modos de aplicação de um sistema adesivo universal: estudo in vitro

ABSTRACT Objective: This study aimed to assess the bond strength and marginal microleakage in composite resin restorations, using the Single Bond Universal adhesive system associated with Ultralux (halogen) and Bluephase (LED) light curing units. Methods: For bond strength, 80 healthy human third molars were divided into halogen light (n=40) and LED (n=40), and subdivided according to the following application techniques for the adhesive system: etch-and-rinse (enamel), self-etching (enamel), etch-and-rinse (dentin), and self-etching (dentin). The teeth were subjected to the microtensile test and the fracture pattern was observed under an optical microscope at 40X magnification; they were analyzed by ANOVA, and Fisher and Tukey's tests (5%). For the marginal microleakage test, 120 class II cavities were prepared in 60 healthy human third molars that were randomly divided into halogen light (n=30) and LED (n=30), and subdivided according to the following application techniques for the adhesive system: etch-and-rinse, selective etching, and self-etching. The teeth were thermocycled 2000 times (±5/55°C), stained in 5% basic fuchsin and sectioned for qualitative and quantitative assessments; they were analyzed by Kruskall-Wallis and Dunn tests (5%). Results: For the bond strength of enamel and dentin, the adhesive application with prior acid etching was better than self-etching (p<0.0001), regardless of the type of light curing unit (p<0.05). Etch-and-rinse showed the lowest microleakage values (p<0.0001). Conclusion: Etch-and-rinse obtained the best results relative to the other application techniques for the adhesive system in both tests, regardless of the type of light curing unit.

RESUMO Objetivo: Avaliar a resistência de união e microinfiltração marginal em restaurações de resina composta, utilizando sistema adesivo Single Bond Universal associado com fotoativadores Ultralux (halógeno) e Bluephase (LED). Métodos: Para resistência de união, oitenta terceiros molares humanos hígidos foram divididos: Halógena (n=40); LED (n=40), sendo subdivididos de acordo com a técnica de aplicação do sistema adesivo: condicionamento total-esmalte; autocondicionante-esmalte; condicionamento total-dentina; autocondicionante-dentina. Os dentes foram submetidos ao teste de microtração e o padrão de fratura foi observado em microscópio ótico - 40X de aumento, analisadas pelos testes ANOVA, Tukey e Fisher (5%). Para o ensaio de microinfiltração marginal, 120 cavidades classe II foram preparadas em sessenta terceiros molares humanos hígidos, aleatoriamente divididos: Halógena (n=30); LED (n=30) e subdivididos de acordo com a técnica de aplicação do sistema adesivo: condicionamento total; condicionamento seletivo; autocondicionante. Os dentes foram termociclados 2000 vezes (±5/55ºC), corados em fucsina básica 5% e seccionados para avaliações qualitativa e quantitativa, analisados pelos testes Kruskall-Wallis e Dunn (5%). Resultados: Para resistência de união em esmalte e dentina, a aplicação do adesivo com condicionamento ácido prévio, foi melhor que o autocondicionante (p<0.0001), independentemente do tipo de fotoativador utilizado (p<0.05). O condicionamento total mostrou os menores valores de microinfiltração, (p<0.0001). Conclusão: O condicionamento total, obteve os melhores resultados em relação às outras técnicas de aplicação do sistema adesivo em ambos os testes, independentemente do tipo de aparelho fotoativador.

Discrepância de Bolton nas diferentes más oclusões e influência dos protocolos de extração / Bolton index in different malocclusions and extraction protocols influence

A obtenção de uma oclusão funcionalmente equilibrada é uma meta perseguida pelos ortodontistas, e um dos pré-requisitos para isso é a existência de proporcionalidade entre os tamanhos mésio-distais dos dentes superiores e inferiores. Com a intenção de localizar o excesso de massa dentária e dirigir a conduta clínica, a análise de Bolton estabelece proporções ideais para regiões anterior e total do arco dentário, evidenciando as discrepâncias. O objetivo deste estudo foi comparar a discrepância de Bolton entre as diferentes más oclusões sagitais e entre diferentes protocolos de extração de quatro pré-molares, avaliando a tendência de se promover discrepância de Bolton nos diferentes protocolos de extração específicos para a camuflagem das más oclusões. Em modelos de estudo de 86 pacientes, com média etária de 18,6 anos, sendo que 31 destes eram portadores de má oclusão de Classe I, 29 pacientes de Classe II e 26 de Classe III, mediu-se as discrepâncias de Bolton com a utilização de paquímetro. Comparou-se as médias dos diâmetros mésio-distais e suas proporções entre grupos de más oclusões, protocolos de extração e protocolos específicos para camuflagem, através da análise de variância. Não ocorreram diferenças estatísticas para discrepância anterior e total entre os grupos de más oclusões avaliados e entre os grupos de protocolos de extração. Com relação aos protocolos de extração para camuflagem, os pacientes Classe III tenderam a apresentar maior discrepância de Bolton às outras más oclusões. É válido considerar esses aspectos durante o plano de tratamento ortodôntico para que a finalização do mesmo não seja dificultada. (AU)

Obtaining a static and functionally balanced occlusion is a goal pursued by orthodontists, and one of pre requirements to it is the existence of proportionality between the mesial-distal sizes of upper and lower teeth. In order to locate the excess dental mass and direct clinical management, the Bolton analysis establishes ideal proportions for both anterior and total arch, highlighting the discrepancies. The objectives of this study were to compare the Bolton discrepancy between the malocclusions and between four premolars extraction protocols, and evaluate the tendency to promote Bolton discrepancy in different specific extraction protocols for camouflage of malocclusions. In plaster models of 86 patients, with a mean age of 18.6 years old, which 31 were suffering from malocclusion of Class I, 29 with Class II and 26 with Class III, it was measured Bolton discrepancies with the use of paquimeter. It was compared the mean values of mesiodistal diameters and their proportions between groups of malocclusion, extraction protocols, and specific protocols for camouflage, through the variance analysis. There were no statistical differences for anterior and total tooth size discrepancy between malocclusion groups and extraction protocols groups. Regarding the extraction protocols for camouflage, patients with Class III tended to show more Bolton discrepancy than other malocclusions. It is worth considering these aspects during orthodontic treatment plan for thereof completion won't be hampered.(AU)

Influência da solução de irrigação sobre a resistência adesiva de um cimento resinoso de dupla polimerização / Influence of solution of irrigation on the resistance of and adhesive resin cement double polymerization

Objetivo: Avaliar a influência de diferentes soluções de irrigação cavitária sobre a resistência de união de um cimento resinoso de dupla polimerização. Material e Método: A partir de incisivos bovinos, foram obtidos 4 grupos (n=15), divididos aleatoriamente de acordo com a solução irrigadora empregada na limpeza cavitária, sendo: G0 - soro fisiológico + condicionamento ácido; G1 ­ EDTA + condicionamento ácido; G2 - Clorexidina 2% + condicionamento ácido + clorexidina 2% e G3 - soro fisiológico + condicionamento ácido + clorexidina 2%. Foram confeccionados cilindros de cimento resinoso para cada coroa, utilizando-se uma matriz de Tygon com diâmetro interno de 1 mm e altura de 2 mm. O teste de resistência adesiva por microcisalhamento foi realizado após 3 meses de armazenamento dos espécimes em soro fisiológico a 37ºC. Os dados foram submetidos ao teste de Kruskall-Wallis, seguido do teste de Dunn (p<0,05). Resultados: Os grupos G0, G1 e G3 não apresentaram diferenças significativas entre si (p>0,05). Os menores valores foram observados no grupo G2 (p<0,05). Conclusões: As soluções irrigadoras EDTA e soro fisiológico utilizadas previamente ao condicionamento ácido da dentina não interferiram, significativamente, na resistência de união, porém, a solução de clorexidina utilizada após o condicionamento ácido influenciou negativamente nos valores de resistência de união.

Objectives: This study aimed to evaluate the influence of different cavity irrigation solutions on the bond strength of a dual-curing resin cement. Methods: From bovine incisors, 4 groups (n=15), were randomly divided according to the irrigating solution for cavity cleaning: G0 ­ saline + acid etching; G1 ­ EDTA + acid etching; G2: Chlorhexidine 2% + acid etching + Chlorhexidine 2%; and G3 ­ Saline + acid etching + Chlorhexidine 2%. Resin cement cylinders were made for each crown, using a Tygon matrix with internal diameter of 1 mm and height of 2 mm. The specimens were stored for 3 months at 37oC, and then subjected to microshear tests. Data were statistically analyzed by Kruskal-Wallis test followed by Dunn (p<0.05). Results: There were no statistically significant differences between G0, G1 and G3 groups (p>0.05). The lowest values were observed in G2 group (p<0.05). Conclusion: The irrigation solutions EDTA and saline used before to the acid etching of dentin did not interfere, significantly, in the bond strength, however, the solution of chlorhexidine used after the acid etching influenced negatively.

Trifluoperazine-Induced Suicidal Erythrocyte Death and S-Nitrosylation Inhibition, Reversed by the Nitric Oxide Donor Sodium Nitroprusside.

BACKGROUND AND PURPOSE: The high potency antipsychotic drug trifluoperazine (10-[3-(4-methyl-1-piperazinyl)-propyl]-2-(trifluoromethyl)-(10)H-phenothiazine dihydrochloride; TFP) may either counteract or promote suicidal cell death or apoptosis. Similar to apoptosis, erythrocytes may enter eryptosis, characterized by phosphatidylserine exposure at the cell surface and cell shrinkage. Eryptosis can be stimulated by an increase in cytoplasmic Ca2+ concentration ([Ca2+]i) and inhibited by nitric oxide (NO). We explored whether TFP treatment of erythrocytes induces phosphatidylserine exposure, cell shrinkage, and calcium influx, whether it impairs S-nitrosylation and whether these effects are inhibited by NO. METHODS: Phosphatidylserine exposure at the cell surface was estimated from annexin-V-binding, cell volume from forward scatter, [Ca2+]i from Fluo3-fluorescence, and protein nitrosylation from fluorescence switch of the Bodipy-TMR/Sypro Ruby signal. RESULTS: Exposure of human erythrocytes to TFP significantly enhanced the percentage of annexin-V-binding cells, raised [Ca2+]i, and decreased S-nitrosylation. The effect of TFP on annexin-V-binding was not affected by removal of extracellular Ca2+ alone, but was significantly inhibited by pre-treatment with sodium nitroprusside (SNP), an effect significantly augmented by additional removal of extracellular Ca2+. A 3 hours treatment with 0.1 µM Ca2+ ionophore ionomycin triggered annexin-V-binding and cell shrinkage, effects fully reversed by removal of extracellular Ca2+. CONCLUSIONS: TFP induces eryptosis and decreases protein S-nitrosylation, effects blunted by nitroprusside. The effect of nitroprusside is attenuated in the presence of extracellular Ca2+.

Peri-implant evaluation of osseointegrated implants subjected to orthodontic forces: results after three years of functional loading.

OBJECTIVE: The objective of this study was to clinically and radiographically assess the peri-implant conditions of implants used as orthodontic anchorage. METHODS: Two groups were studied: 1) a test group in which osseointegrated implants were used as orthodontic anchorage, with the application of 200-cN force; and 2) a control group in which implants were not subjected to orthodontic force, but supported a screw-retained prosthesis. Clinical evaluations were performed three, six and nine months after prosthesis installation and 1- and 3-year follow-up examinations. Intraoral periapical radiographs were obtained 30 days after surgical implant placement, at the time of prosthesis installation, and one, two and three years thereafter. The results were compared by Kruskal-Wallis test. RESULTS: There was no statistically significant difference in clinical probing depth (p = 0.1078) or mesial and distal crestal bone resorption (p = 0.1832) during the study period. After three years of follow-up, the mean probing depth was 2.21 mm for the control group and 2.39 mm for the test group. The implants of the control group showed a mean distance between the bone crest and implant shoulder of 2.39 mm, whereas the implants used as orthodontic anchorage showed a mean distance of 2.58 mm at the distal site. CONCLUSION: Results suggest that the use of stable intraoral orthodontic anchorage did not compromise the health of peri-implant tissues or the longevity of the implant.

Peri-implant evaluation of osseointegrated implants subjected to orthodontic forces: results after three years of functional loading

ABSTRACT Objective: The objective of this study was to clinically and radiographically assess the peri-implant conditions of implants used as orthodontic anchorage. Methods: Two groups were studied: 1) a test group in which osseointegrated implants were used as orthodontic anchorage, with the application of 200-cN force; and 2) a control group in which implants were not subjected to orthodontic force, but supported a screw-retained prosthesis. Clinical evaluations were performed three, six and nine months after prosthesis installation and 1- and 3-year follow-up examinations. Intraoral periapical radiographs were obtained 30 days after surgical implant placement, at the time of prosthesis installation, and one, two and three years thereafter. The results were compared by Kruskal-Wallis test. Results: There was no statistically significant difference in clinical probing depth (p = 0.1078) or mesial and distal crestal bone resorption (p = 0.1832) during the study period. After three years of follow-up, the mean probing depth was 2.21 mm for the control group and 2.39 mm for the test group. The implants of the control group showed a mean distance between the bone crest and implant shoulder of 2.39 mm, whereas the implants used as orthodontic anchorage showed a mean distance of 2.58 mm at the distal site. Conclusion: Results suggest that the use of stable intraoral orthodontic anchorage did not compromise the health of peri-implant tissues or the longevity of the implant.

RESUMO Introdução: o objetivo do presente estudo foi avaliar, clínica e radiograficamente, as condições peri-implantares de implantes usados como ancoragem ortodôntica. Métodos: dois grupos foram estudados: 1) Grupo Teste - no qual os implantes osseointegráveis foram utilizados como ancoragem ortodôntica, com aplicação de uma força de 200cN; e 2) Grupo Controle - no qual os implantes não foram submetidos à ancoragem ortodôntica, apenas serviram de suporte para fixação de prótese implantossuportada. Avaliações clínicas foram realizadas aos 3, 6 e 9 meses após a instalação das próteses, e após 1 e 3 anos de acompanhamento. Radiografias periapicais intrabucais foram obtidas 30 dias após a colocação do implante, no momento da instalação da prótese e após 1, 2 e 3 anos de acompanhamento. Os resultados foram comparados pelo teste de Kruskal-Wallis. Resultados: não houve diferenças quanto à profundidade clínica de sondagem (p = 0,1078) e a reabsorção das cristas ósseas mesial e distal (p = 0,1832) durante o período avaliado. Após três anos de acompanhamento, a média de profundidade de sondagem foi de 2,21mm para o Grupo Controle e de 2,39mm para o Grupo Teste. Os implantes do Grupo Controle apresentaram distância média de 2.39mm entre a crista óssea e o ombro do implante, enquanto os implantes usados como ancoragem ortodôntica mostraram distância média de 2,58mm na distal. Conclusão: esses resultados sugerem que o uso de uma ancoragem intrabucal estável não compromete a saúde dos tecidos peri-implantares ou a longevidade do implante.

Characterization of Microvesicles Released from Human Red Blood Cells.

BACKGROUND/AIMS: Extracellular vesicles (EVs) are spherical fragments of cell membrane released from various cell types under physiological as well as pathological conditions. Based on their size and origin, EVs are classified as exosome, microvesicles (MVs) and apoptotic bodies. Recently, the release of MVs from human red blood cells (RBCs) under different conditions has been reported. MVs are released by outward budding and fission of the plasma membrane. However, the outward budding process itself, the release of MVs and the physical properties of these MVs have not been well investigated. The aim of this study is to investigate the formation process, isolation and characterization of MVs released from RBCs under conditions of stimulating Ca2+ uptake and activation of protein kinase C. METHODS: Experiments were performed based on single cell fluorescence imaging, fluorescence activated cell sorter/flow cytometer (FACS), scanning electron microscopy (SEM), atomic force microscopy (AFM) and dynamic light scattering (DLS). The released MVs were collected by differential centrifugation and characterized in both their size and zeta potential. RESULTS: Treatment of RBCs with 4-bromo-A23187 (positive control), lysophosphatidic acid (LPA), or phorbol-12 myristate-13 acetate (PMA) in the presence of 2 mM extracellular Ca2+ led to an alteration of cell volume and cell morphology. In stimulated RBCs, exposure of phosphatidylserine (PS) and formation of MVs were observed by using annexin V-FITC. The shedding of MVs was also observed in the case of PMA treatment in the absence of Ca2+, especially under the transmitted bright field illumination. By using SEM, AFM and DLS the morphology and size of stimulated RBCs, MVs were characterized. The sizes of the two populations of MVs were 205.8 ± 51.4 nm and 125.6 ± 31.4 nm, respectively. Adhesion of stimulated RBCs and MVs was observed. The zeta potential of MVs was determined in the range from - 40 mV to - 10 mV depended on the solutions and buffers used. CONCLUSION: An increase of intracellular Ca2+ or an activation of protein kinase C leads to the formation and release of MVs in human RBCs.