RESUMO
Aim: The objective of this study was to compare the efficiencies of different adhesive systems used to bond orthodontic brackets as well as the fracture pattern during debonding on bovine teeth. Methods: The sample included 45 specimens assigned to 3 groups according to the adhesive system applied: Group I: Transbond XT (3M Unitek®, Monrovia/CA -USA), Group II: Orthocem (FGM® Joinville/SC-BR), and Group III: Orthobond (Morelli®, Sorocaba/SP-BR). For this purpose, metal brackets were bonded to bovine teeth following the instructions from each manufacturer. The specimens were subjected to a shear test to assess bond strength (BS). Finally, after debonding, the adhesive remnant index (ARI) was estimated. Results: The average shear strength for a tooth bonded using the adhesive system Transbond XT was 16.39 MPa, while it was 18.08 Mpa for Orthocem and 7.28 Mpa for Orthobond; The Tukey test revealed no statistically significant differences between groups I and II (p < 0.01) and group III differed statistically from groups I and II. Conclusion: In conclusion, both adhesive systems Transbond XT and Orthocem attained higher bond strength values than Orthobond; the fracture pattern was similar for all adhesive systems applied
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Animais , Bovinos , Colagem Dentária , Braquetes Ortodônticos , Esmalte Dentário , Resistência ao CisalhamentoRESUMO
Extraction is very frequent indication in orthodontic planning, especially when there are crowding, biprotrusion, and aesthetically unpleasant profiles. Next to extraction comes space closure, which represents a challenge for orthodontists because of extended treatment time, discomfort created for the patient, tissue tolerance, and stability concerns. When it comes to what mechanics to choose for space closure, loops present two major advantages in relation to sliding mechanics: absence of abrasion and possibility to reach pure dental translation. A case is presented where an adult female patient with early loss of the first lower permanent molars, minor lower crowding, and tooth biprotrusion was treated with upper first bicuspids extraction along with upper and lower space closure done with T-loops to promote best space closure control in order to correct the malocclusion and enhance facial aesthetics.
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Embora incomum, a impacção de incisivos centrais superiores é geralmente diagnosticada precocemente, devido à importância destes dentes na função mastigatória e na aparência do indivíduo. O objetivo deste trabalho foi relatar dois casos clínicos nos quais uma abordagem cirúrgica e ortodôntica foi realizada para tratar incisivos centrais impactados. Em ambos os casos, foi realizada a expansão rápida da maxila com o auxílio de um aparelho disjuntor de Haas. Da mesma forma, foi efetuada a exposição cirúrgica e o tracionamento ortodôntico do incisivo central superior impactado. Forças ortodônticas leves foram utilizadas durante todo o tracionamento ortodôntico, as quais foram aplicadas em arcos rígidos. Ao final do tratamento, os dentes apresentavam uma altura de coroa clínica adequada, contornos gengivais satisfatórios e vitalidade pulpar. De acordo com o desfecho clínico dos dois casos apresentados, pôde-se concluir que a exposição cirúrgica bem planejada, associada ao tracionamento ortodôntico dos dentes impactados contribuiu para os resultados positivos observados neste estudo...
Although uncommon, the impaction of maxillary central incisors is usually early diagnosed, due to the importance of these teeth in masticatory function and appearance of the individual. The aim of this paper was to report two clinical cases, in which surgical and orthodontic approach were performed, in order to treat impacted central incisors. In both cases, we have done the rapid disjunction of the midpalatal suture, as well as exposure and orthodontic traction of the impacted maxillary central incisor. Light forces were used during the all the orthodontic traction, which were applied on rigid archs. It was noted that the teeth presented adequate clinical crown height, satisfactory gingival contours and pulp vitality. It can be concluded that a well-planned surgical exposure of the impacted teeth in association with orthodontic traction contributed to periodontal and aesthetic optimal treatment outcomes...
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Humanos , Masculino , Criança , Incisivo/cirurgia , Ortodontia Corretiva , Dente ImpactadoRESUMO
Abstract Aim : To assess the surface topography and chemical composition of three brands of as-received mini-implants (SIN(r), Morelli(r), and Conexao(r)). Methods: Twelve mini-implants of each brand were analyzed by scanning electron microscopy and energy dispersive X-ray (EDX). Results: There was no significant differences among SIN(r), Morelli(r), and Conexao(r) mini-implants comparing their surface topography by visualization of SEM micrographs and analysis of scores. The EDX analysis showed statistically significant difference among them for the amount of Ti, Al and V. Miniimplants SIN(r)presented also N and O in their composition. Conclusions: In conclusion, the miniimplants Morelli(r), SIN(r) and Conexao(r) presented Ti as main component of the alloy. Remaining components, such as Al and V, were also observed in all the analyzed brands, with differences among them. Only SIN(r)mini-implants presented N and O. As far as surface topography is concerned, there are no differences among the three brands of mini-implants.
Assuntos
Ortodontia , Titânio , Procedimentos de Ancoragem OrtodônticaRESUMO
INTRODUCTION: The finite element method (FEM) is an engineering resource applied to calculate the stress and deformation of complex structures, and has been widely used in orthodontic research. With the advantage of being a non-invasive and accurate method that provides quantitative and detailed data on the physiological reactions possible to occur in tissues, applying the FEM can anticipate the visualization of these tissue responses through the observation of areas of stress created from applied orthodontic mechanics. OBJECTIVE: This article aims at reviewing and discussing the stages of the finite element method application and its applicability in Orthodontics. RESULTS: FEM is able to evaluate the stress distribution at the interface between periodontal ligament and alveolar bone, and the shifting trend in various types of tooth movement when using different types of orthodontic devices. Therefore, it is necessary to know specific software for this purpose. CONCLUSIONS: FEM is an important experimental method to answer questions about tooth movement, overcoming the disadvantages of other experimental methods.
Assuntos
Análise de Elementos Finitos , Ortodontia Corretiva/métodos , Processo Alveolar/fisiologia , Fenômenos Biomecânicos , Humanos , Modelos Biológicos , Aparelhos Ortodônticos , Ligamento Periodontal/fisiologia , Software , Estresse Mecânico , Técnicas de Movimentação Dentária/métodosRESUMO
INTRODUCTION: The finite element method (FEM) is an engineering resource applied to calculate the stress and deformation of complex structures, and has been widely used in orthodontic research. With the advantage of being a non-invasive and accurate method that provides quantitative and detailed data on the physiological reactions possible to occur in tissues, applying the FEM can anticipate the visualization of these tissue responses through the observation of areas of stress created from applied orthodontic mechanics. OBJECTIVE: This article aims at reviewing and discussing the stages of the finite element method application and its applicability in Orthodontics. RESULTS: FEM is able to evaluate the stress distribution at the interface between periodontal ligament and alveolar bone, and the shifting trend in various types of tooth movement when using different types of orthodontic devices. Therefore, it is necessary to know specific software for this purpose. CONCLUSIONS: FEM is an important experimental method to answer questions about tooth movement, overcoming the disadvantages of other experimental methods. .
INTRODUÇÃO: o Método de Elementos Finitos (MEF) é um recurso da Engenharia empregado para calcular o estresse e a deformação de estruturas complexas, e tem sido amplamente utilizado nas pesquisas em Ortodontia. Apresenta a vantagem de ser um método não-invasivo e preciso, que fornece dados quantitativos e detalhados acerca das reações fisiológicas que podem ocorrer nos tecidos. OBJETIVO: esse artigo pretende realizar uma revisão da literatura sobre as etapas para realização do Método de Elementos Finitos, bem como de sua aplicabilidade na Ortodontia. RESULTADOS: o MEF é capaz de avaliar a distribuição do estresse na interface entre o ligamento periodontal e o osso alveolar, bem como a tendência de deslocamento em diversos tipos de movimentos dentários, quando utilizados diferentes tipos de aparelhos. Para tanto, é necessário conhecimento de softwares específicos para esse fim. CONCLUSÕES: o MEF é um importante método experimental que pode esclarecer questionamentos acerca da movimentação dentária, superando as desvantagens de outros métodos experimentais. .
Assuntos
Fracionamento Celular/métodos , Saccharomyces cerevisiae/química , Centrifugação com Gradiente de Concentração , Organelas/química , Reprodutibilidade dos Testes , Frações Subcelulares , Fatores de TempoRESUMO
Odontomas are the most common odontogenic tumours of the maxillary bones, characterised by a slow growth and benign behaviour. They are usually small, asymptomatic and diagnosed after routine radiographic examination. The aim of this study was to report a case of a compound odontoma in the anterior maxilla of a 7-year-old girl, which was causing the impaction of the maxillary right central and lateral incisors, as well as the prolonged retention of the corresponding primary teeth. We also aimed to review the literature about these tumours, since they are not part of the dentist's day-to-day clinical practice. The clinical and radiographic features, the diagnosis and treatment of the case were discussed in this work.
Assuntos
Neoplasias Maxilares/complicações , Neoplasias Maxilares/diagnóstico por imagem , Odontoma/complicações , Odontoma/diagnóstico por imagem , Dente Impactado/etiologia , Criança , Feminino , Humanos , Neoplasias Maxilares/cirurgia , Odontoma/cirurgia , RadiografiaRESUMO
This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10); RL = conventional brackets, Roth Light Morelli® (n = 10); NF = nickel-free brackets, Nickel-Free Morelli® (n = 10); and RM = nickel-free brackets, Roth Max Morelli® (n = 10). Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared. The elemental composition was analyzed by EDS. According to surface analysis, groups ABZ and RL showed a homogeneous surface, with better finishing, whereas the surfaces in groups NF and RM were rougher. The chemical components with the highest percentage were Fe, Cr and C. Groups NF and MR showed no nickel in their composition. In conclusion, the bracket surface of the ABZ and RL groups was more homogeneous, with grooves and pores, whereas the surfaces in groups NF and RM showed numerous flaws, cracks, pores and grooves. The chemical composition analysis confirmed that the nickel-free brackets had no Ni in their composition, as confirmed by the manufacturer's specifications, and were therefore safe to use in patients with a medical history of allergy to this metal.
Assuntos
Metais/química , Níquel/química , Braquetes Ortodônticos , Ligas/química , Análise de Variância , Corrosão , Teste de Materiais , Microscopia Eletrônica de Varredura , Valores de Referência , Espectrometria por Raios X , Estatísticas não Paramétricas , Propriedades de SuperfícieRESUMO
This study aims at comparing conventional and nickel-free metal bracket surface characteristics with elemental composition by scanning electron microscopy (SEM), using energy dispersive spectroscopy (EDS). The sample consisted of 40 lower incisor brackets divided into four groups: ABZ = conventional brackets, Kirium Abzil 3M® (n = 10); RL = conventional brackets, Roth Light Morelli® (n = 10); NF = nickel-free brackets, Nickel-Free Morelli® (n = 10); and RM = nickel-free brackets, Roth Max Morelli® (n = 10). Qualitative evaluation of the bracket surface was performed using SEM, whereby surface features were described and compared. The elemental composition was analyzed by EDS. According to surface analysis,groups ABZ and RL showed a homogeneous surface, with better finishing, whereas the surfaces in groups NF and RM were rougher. The chemical components with the highest percentage were Fe, Cr and C. Groups NF and MR showed no nickel in their composition. In conclusion, the bracket surface of the ABZ and RL groups was more homogeneous, with grooves and pores, whereas the surfaces in groups NF and RM showed numerous flaws, cracks, pores and grooves. The chemical composition analysis confirmed that the nickel-free brackets had no Ni in their composition, as confirmed by the manufacturer’s specifications, and were therefore safe to use in patients with a medical history of allergy to this metal.
Assuntos
Metais/química , Níquel/química , Braquetes Ortodônticos , Análise de Variância , Ligas/química , Corrosão , Teste de Materiais , Microscopia Eletrônica de Varredura , Valores de Referência , Espectrometria por Raios X , Estatísticas não Paramétricas , Propriedades de SuperfícieRESUMO
O aumento do interesse por parte dos adultos em tratamentos ortodônticos tem levado as empresas a desenvolverem novas alternativas que utilizem aparelhos ortodônticos menos perceptíveis e mais estéticos. Os alinhadores estéticos destacam-se entre as opções de tratamento que atendem a estas expectativas. Serão apresentados neste trabalho alguns aspectos relevantes sobre estes dispositivos, além de dois casos clínicos tratados com o sistema Essix MTM (Dentsply), em que todos os objetivos estéticos e funcionais propostos foram alcançados. Os resultados encontrados neste trabalho corroboram com a ideia de que, quando bem indicados, os alinhadores estéticos são uma opção viável de tratamento dentro do cotidiano clínico do ortodontista...
The increased interest in orthodontics by adults has led companies to develop new treatment alternatives that use less visible and more aesthetic orthodontic appliances. The aesthetic aligners stand out among the treatment options that attend these expectations. This paper presented some relevant aspects of these devices, as well as two cases treated with Essix MTM (Dentsply) system, in which all aesthetic and functional objectives proposed treatment have been achieved. The results of this study support the idea that, when properly indicated, aesthetic aligners are a viable treatment option within the clinical routine of the orthodontist...
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Humanos , Masculino , Adolescente , Pessoa de Meia-Idade , Estética Dentária , Técnicas de Movimentação Dentária , Aparelhos Ortodônticos RemovíveisRESUMO
INTRODUCTION: Nicotine is harmful to angiogenesis, osteogenesis and synthesis of collagen. OBJECTIVE: The aim of this study was to investigate the effect of nicotine on bone remodeling during orthodontic movement in rats. METHODS: Eighty male Wistar rats were randomly divided into three groups: Group C (control), group CM (with orthodontic movement) and group NM (nicotine with orthodontic movement) groups. The animals comprising groups C and CM received 0.9% saline solution while group NM received nicotine solution (2 mg/kg). A nickel-titanium closed-coil spring was used to induce tooth movement. The animals were euthanized and tissue specimens were histologically processed. Blood vessels, Howship's lacunae and osteoclast-like cells present in the tension and compression areas of periodontal ligaments were quantified. The extent of bone formation was evaluated under polarized light, to determine the percentage of immature/mature collagen. RESULTS: It was observed lower blood vessel densities in the NM group in comparison to the CM group, three (p < 0.001) and seven (p < 0.05) days after force application. Osteoclast-like cells and Howship's lacunae in the NM group presented lower levels of expression, in comparison to the CM group, with significant differences on day 7 (p < 0.05 for both variables) and day 14 (p < 0.05 for osteoclast-like cells and p < 0.01 for Howship's lacunae). The percentage of immature collagen was increased in the NM group in comparison to the CM group, with a statistically significant difference on day 3 (p < 0.05), day 7 (p < 0.001), day 14 (p < 0.001) and day 21 (p < 0.001). CONCLUSIONS: Nicotine affects bone remodeling during orthodontic movement, reducing angiogenesis, osteoclast-like cells and Howship's lacunae, thereby delaying the collagen maturation process in new bone matrix.
Assuntos
Processo Alveolar/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Nicotina/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Técnicas de Movimentação Dentária , Processo Alveolar/irrigação sanguínea , Animais , Reabsorção Óssea/patologia , Colágeno/efeitos dos fármacos , Ligas Dentárias/química , Cemento Dentário/irrigação sanguínea , Cemento Dentário/efeitos dos fármacos , Masculino , Dente Molar/irrigação sanguínea , Dente Molar/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Níquel/química , Fios Ortodônticos , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ligamento Periodontal/irrigação sanguínea , Distribuição Aleatória , Ratos , Ratos Wistar , Estresse Mecânico , Fatores de Tempo , Titânio/química , Técnicas de Movimentação Dentária/instrumentação , Raiz Dentária/irrigação sanguínea , Raiz Dentária/efeitos dos fármacosRESUMO
Introduction: Nicotine is harmful to angiogenesis, osteogenesis and synthesis of collagen. Objective: The aim of this study was to investigate the effect of nicotine on bone remodeling during orthodontic movement in rats. Methods: Eighty male Wistar rats were randomly divided into three groups: Group C (control), group CM (with orthodontic movement) and group NM (nicotine with orthodontic movement) groups. The animals comprising groups C and CM received 0.9% saline solution while group NM received nicotine solution (2 mg/kg). A nickel-titanium closed-coil spring was used to induce tooth movement. The animals were euthanized and tissue specimens were processed histologically. We quantified blood vessels, Howship's lacunae and osteoclast-like cells present in the tension and compression areas of periodontal ligaments. The extent of bone formation was evaluated under polarized light to determine the percentage of immature/mature collagen. Results: We observed lower blood vessel densities in the NM group in comparison to the CM group, three (p < 0.001) and seven (p < 0.05) days after force application. Osteoclast-like cells and Howship's lacunae in the NM group presented lower levels of expression in comparison to the CM group, with significant differences on day 7 (p < 0.05 for both variables) and day 14 (p < 0.05 for osteoclast-like cells and p < 0.01 for Howship's lacunae). The percentage of immature collagen increased in the NM group in comparison to the CM group with a statistically significant difference on day 3 (p < 0.05), day 7 (p < 0.001), day 14 (p < 0.001) and day 21 (p < 0.001). Conclusions: Nicotine affects bone remodeling during orthodontic movement, reducing angiogenesis, osteoclast-like cells and Howship's lacunae, thereby delaying the collagen maturation process in developed bone matrix. .
Introdução: a nicotina apresenta efeito prejudicial sobre a angiogênese, osteogênese e síntese de colágeno. Objetivo: investigar a ação da nicotina sobre a remodelação óssea durante o movimento dentário induzido em ratos. Métodos: oitenta ratos machos Wistar foram divididos em três grupos: grupo C (sem indução de movimento dentário e sem a ação da nicotina - controle); grupo CM (indução de movimento dentário) e grupo NM (indução de movimento dentário associado à ação da nicotina). Os animais dos grupos C e CM receberam solução salina a 0,9% e os animais do grupo NM receberam nicotina (solução PA a 98% diluída em solução salina a 0,9% estéril) por via subcutânea (2mg/kg). Após a eutanásia dos animais, com 3, 7, 14 e 21 dias de uso da mola ortodôntica, os espécimes teciduais foram processados histologicamente e quantificou-se o número de vasos sanguíneos, lacunas de Howship e células osteoclásticas nos lados de tração e compressão do ligamento periodontal. A neoformação óssea foi avaliada por meio de luz polarizada, para determinar a porcentagem de colágeno maduro e imaturo. Resultados: observou-se que a quantidade de vasos sanguíneos diminuiu no grupo NM, quando comparado ao grupo CM, nos períodos de três (p < 0,001) e sete (p < 0,05) dias. Quanto às células osteoclásticas e lacunas de Howship, o grupo NM apresentou menores níveis de expressão em relação ao grupo CM, com diferença estatisticamente significativa nos períodos de 7 e 14 dias. A porcentagem de colágeno imaturo apresentou-se aumentada no grupo NM, quando comparado ao grupo CM, em todos os períodos analisados, com diferença e...
Assuntos
Animais , Masculino , Ratos , Processo Alveolar/efeitos dos fármacos , Remodelação Óssea/efeitos dos fármacos , Nicotina/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Técnicas de Movimentação Dentária , Processo Alveolar/irrigação sanguínea , Reabsorção Óssea/patologia , Colágeno/efeitos dos fármacos , Ligas Dentárias/química , Cemento Dentário/irrigação sanguínea , Cemento Dentário/efeitos dos fármacos , Dente Molar/irrigação sanguínea , Dente Molar/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Níquel/química , Fios Ortodônticos , Osteoclastos/efeitos dos fármacos , Osteogênese/efeitos dos fármacos , Ligamento Periodontal/irrigação sanguínea , Distribuição Aleatória , Ratos Wistar , Estresse Mecânico , Fatores de Tempo , Titânio/química , Técnicas de Movimentação Dentária/instrumentação , Raiz Dentária/irrigação sanguínea , Raiz Dentária/efeitos dos fármacosRESUMO
The aim of this study was to evaluate, by histological analysis, the effect of growth hormone (GH) on periodontal ligament and alveolar bone during experimental tooth movement in rats. Eighty male Wistar rats divided into control (C) and experimental (E) groups were examined after 3, 7, 14 and 21 days under controlled climate conditions. Orthodontic force (30 cN) was applied on the maxillary first molar by an orthodontic appliance. Group E received 0.1 IU/kg/day of GH and Group C received 0.5 mL/kg/day of saline. The samples were processed and evaluated under optical microscopy and polarized light microscopy. The Kruskal Wallis test was applied to compare the intergroup variables at 5% significance level. Group E presented a larger number of osteoclasts on the 3rd and 7th days and Howship lacunae on the 3 rd day, a smaller number of blood vessels and greater amount of mature collagen on the 3 rd and 7 th days than Group C (p<0.05). It was concluded that GH accelerated and intensified bone resorption and produced delay in immature collagen formation during experimental tooth movement.
O objetivo deste estudo foi avaliar histologicamente o efeito do hormônio de crescimento (HC) no ligamento periodontal e osso alveolar, durante a movimentação dentária induzida em ratos. Oitenta ratos Wistar, machos, divididos nos grupos controle e experimental, foram observados nos dias 3, 7, 14 e 21. Foi aplicada força ortodôntica (30 cN) sobre o primeiro molar superior por meio de um dispositivo ortodôntico. No grupo experimental foi administrada 0,1 UI/kg/dia de HC e, no grupo controle, 0,5 mL/kg/dia de solução salina. As amostras foram processadas e avaliadas por microscopia de luz e luz polarizada. O teste de Kruskal Wallis foi utilizado para a comparação das variáveis intergrupos. Verificou-se que o grupo experimental apresentou maior quantidade de osteoclastos nos 3° e 7° dias e de lacunas de Howship no 3° dia, menor quantidade de vasos sanguíneos e maior quantidade de colágeno maduro nos 3° e 7° dias do que no grupo controle (p<0,05). Concluiu-se que o HC acelerou e intensificou a reabsorção óssea e produziu atraso na formação de colágeno imaturo, durante o movimento ortodôntico induzido.
Assuntos
Animais , Masculino , Ratos , Processo Alveolar/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Técnicas de Movimentação Dentária , Ligamento Periodontal/efeitos dos fármacos , Ratos WistarRESUMO
A busca por um material adesivo para recolagem de bráquetes com adesão adequada desperta interesse ao ortodontista. A resina fotopolimerizável ReBond® foi introduzida na Ortodontia com esta finalidade. Objetivos: Avaliar e comparar o desempenho in vitro do ReBond® com a resina Transbond XT® na recolagem de bráquetes metálicos. Materiais e Métodos: Noventa incisivos inferiores bovinos foram divididos em 3 grupos (n=30): Grupo I: bráquetes colados com resina Transbond® e colagem de novos bráquetes com resina Transbond®; Grupo II: bráquetes colados com resina Transbond® e recolados com resina Rebond®; Grupo III: bráquetes colados e recolados com resina Transbond®. Os corpos de prova foram submetidos ao teste de cisalhamento na máquina de ensaio universal DL 500 (EMIC). Os valores obtidos foram analisados estatisticamente e apresentaram distribuição normal (ANOVA e TUKEY-HSD). Resultados: Os resultados evidenciaram existir diferença estatisticamente significante entre grupos e en¬tre colagem/recolagem dos bráquetes. A força de colagem inicial demonstrou ser sempre superior à força de recolagem, em todos os grupos experimentais. Conclusões: A força de recolagem dos bráquetes com Rebond® e Transbond® apresentaram forças de adesão adequadas ao uso clínico...
The search for an adhesive material for satisfactory rebond of brackets awakens interest to the orthodontist. The ReBond® fotopolimerizable resin was introduced in Orthodontics with this purpose. Objectives: To assess and compare the performance of in vitro ReBond® with Transbond XT® resin of metallic orthodontic brackets in rebonding. Materials and Method: Ninety bovine lower incisors were divided into 3 groups (n = 30): Group I: brackets bonded with Transbond® resin and bond of new brackets with Transbond® resin; Group II: brackets bonded with Transbond® resin and rebonded with Rebond® resin; Group III: brackets bonded and rebonded with Transbond® resin. Samples were submitted to a shear test in a universal testing machine DL 500 (EMIC). Data were statistically analyzed and showed normal distribution (ANOVA and TUKEY-HSD). Results: The results showed significant difference between groups and between bond/rebond of brackets. The initial bond strength was always higher than the rebond strength in all experimental groups. Conclusions: The strength of rebonding of the brackets rebonded with Rebond® and Transbond® was adequate to the appropriate clinical use...
Assuntos
Animais , Bovinos , Cimentos de Resina/química , Colagem Dentária/métodos , Braquetes Ortodônticos , Análise de Variância , Teste de Materiais , Resistência ao Cisalhamento , Propriedades de Superfície , Fatores de TempoRESUMO
The aim of this study was to evaluate, by histological analysis, the effect of growth hormone (GH) on periodontal ligament and alveolar bone during experimental tooth movement in rats. Eighty male Wistar rats divided into control (C) and experimental (E) groups were examined after 3, 7, 14 and 21 days under controlled climate conditions. Orthodontic force (30 cN) was applied on the maxillary first molar by an orthodontic appliance. Group E received 0.1 IU/kg/day of GH and Group C received 0.5 mL/kg/day of saline. The samples were processed and evaluated under optical microscopy and polarized light microscopy. The Kruskal Wallis test was applied to compare the intergroup variables at 5% significance level. Group E presented a larger number of osteoclasts on the 3rd and 7th days and Howship lacunae on the 3 rd day, a smaller number of blood vessels and greater amount of mature collagen on the 3 rd and 7 th days than Group C (p<0.05). It was concluded that GH accelerated and intensified bone resorption and produced delay in immature collagen formation during experimental tooth movement.
Assuntos
Processo Alveolar/efeitos dos fármacos , Hormônio do Crescimento/farmacologia , Técnicas de Movimentação Dentária , Animais , Masculino , Ligamento Periodontal/efeitos dos fármacos , Ratos , Ratos WistarRESUMO
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.
RESUMO
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.
Assuntos
Processo Alveolar/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Remodelação Óssea/efeitos dos fármacos , Dexametasona/farmacologia , Diclofenaco/farmacologia , Ligamento Periodontal/efeitos dos fármacos , Técnicas de Movimentação Dentária , Processo Alveolar/patologia , Animais , Remodelação Óssea/fisiologia , Colágeno/metabolismo , Masculino , Microscopia de Polarização , Ligamento Periodontal/patologia , Ratos , Ratos WistarRESUMO
A seleção dos materiais ortodônticos é passo importante para a obtenção do sucesso na prática clínica, principalmente diante da velocidade com que os materiais são lançados no mercado. Para auxiliar o profissional nesta escolha, esta pesquisa teve como objetivo comparar a resistência ao cisalhamento dos bráquetes metálicos Roth Standard e Roth Max (Morelli, Sorocaba/SP), colados com dois diferentes sistemas adesivos: Orthobond (Morelli, Sorocaba/SP) e Tansbond XT (3M Unitek, Monrovia/CA), além de avaliar o Índice de Adesivo Remanescente dos grupos testados. Buscou-se também avaliar qualitativamente as bases dos bráquetes por meio de microscopia eletrônica de varredura. Os bráquetes foram colados em dentes bovinos e a amostra foi dividida em quatro grupos de vinte dentes cada: 1 Roth Standard colados com adesivo Orthobond; 2 - Roth Standard colados com adesivo Transbond XT; 3 - Roth Max colados com adesivo Orthobond e 4 - Roth Max colados com adesivo Transbond XT. Foi realizado o teste de cisalhamento em uma máquina de ensaios universal e computados os valores em MPa. Posteriormente, a base do bráquete foi avaliada segundo o Índice de Adesivo Remanescente, que visa identificar a interface de fratura durante a descolagem. Os resultados obtidos evidenciaram a superioridade do bráquete Roth Max no que tange às suas características retentivas, assim como também comprovaram a superioridade do sistema adesivo Transbond XT nas colagens ortodônticas
The selection of orthodontic materials is an important step towards achieving success in clinical practice, especially given the speed with which the materials are released to the market. To assist the professional in this choice, this study aimed to compare the shear strength of metal brackets Roth Max and Roth Standard (Morelli, Sorocaba / SP), bonded with two different adhesives: Orthobond (Morelli, Sorocaba / SP) and Tansbond XT (3M Unitek, Monrovia / CA), and to evaluate the adhesive remnant index of the groups tested. It was attempted to evaluate qualitatively also the bases of the brackets by means of scanning electron microscopy. The brackets were bonded to bovine teeth and the sample was divided into four groups of twenty teeth each:1 - Roth Standard Orthobond bonded with adhesive; 2 - Roth Standard bonded with Transbond XT; 3 - Max Roth bonded with adhesive Orthobond, and 4 - Roth Max bonded with Transbond XT. Test was performed in a shear testing machine universal and computed values are in MPa. There after, the bracket base was evaluated according to the adhesive remnant index, which aims to identify the fracture interface during takeoff. The results showed the superiority of the bracket Roth Max in relation to their retentive characteristics and also proved the superiority of the adhesive system Transbond XT bonding in orthodontics.
Assuntos
Animais , Bovinos , Braquetes Ortodônticos , Ortodontia , Resistência ao CisalhamentoRESUMO
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<0,05) quando comparados os momentos final e inicial, embora não houvesse diferença significativa entre os modos respiratórios. Em nenhuma das variáveis se observou interação entre o modo respiratório e os momentos. CONCLUSÃO: há alteração estatisticamente significativa do pogônio e do nariz no plano anteroposterior no decorrer do crescimento, porém sem qualquer interferência do modo respiratório.
INTRODUCTION: The soft tissue profile results from complex changes in the hard and soft tissues of the face. The pogonion and the nose are dominant facial structures that determine the degree of profile convexity and should, therefore, be analyzed and included in orthodontic treatment planning. OBJECTIVE: To conduct a longitudinal evaluation of the anteroposterior dimensional changes of the pogonion and the nose of individuals with Angle Class II, division 1 malocclusion at two time points during craniofacial development. METHODS: Lateral cephalograms were obtained for 40 individuals - 23 nasal breathers (NB) and 17 mouth breathers (MB). RESULTS: Linear and angular measures were obtained: UL'-Pog', UL'-B', B'-Pog', Pog'-PogTeg', NB Line, Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn and Prn-Sn-UL. Two-way ANOVA was used to detect differences between mean values according to time points and/or breathing patterns. The UL'-B', Pog'-PogTeg', NB line and Pog-NB, N'-Prn, Prn-NPog, N-Prn-Sn and Prn-Sn-UL variables had significant differences (p<0.05) between the two time points, but there were no significant differences between breathing patterns. No interaction was found between breathing patterns and time points for any variable. CONCLUSION: The pogonion and the nose undergo significant changes in the anteroposterior plane during growth, but breathing patterns do not significantly affect changes.
Assuntos
Humanos , Masculino , Feminino , Adolescente , Respiração Bucal , Mandíbula/anatomia & histologia , Nariz , Respiração , OrtodontiaRESUMO
UNLABELLED: 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 influenced dental alterations.