RESUMO
OBJECTIVE: To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces. METHODS: The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamond bur followed by conventional direct bonding by means of light-cured composite resin; discs in group 3 were bonded by means of CAAR (alternative adhesive); and discs in group 4 had surfaces roughened with a diamond bur followed by direct bonding by means of CAAR. Shear bond strength values were determined after 24 hours by means of a universal testing machine at a speed of 0.5 mm/min, and compared by analysis of variance followed by post-hoc Tukey test. Adhesive remnant index (ARI) was measured and compared among groups by means of Kruskal-Wallis and Dunn tests. RESULTS: Groups 3 and 4 had significantly greater shear bond strength values in comparison to groups 1 and 2. Groups 3 and 4 yielded similar results. Group 2 showed better results when compared to group 1. In ARI analyses, groups 1 and 2 predominantly exhibited a score equal to 0, whereas groups 3 and 4 predominantly exhibited a score equal to 3. CONCLUSIONS: Direct bonding of brackets to acrylic resin surfaces using CAAR yielded better results than light-cured composite resin. Surface preparation with diamond bur only increased shear bond strength in group 2.
Assuntos
Coroas , Colagem Dentária/métodos , Restauração Dentária Temporária , Braquetes Ortodônticos , Condicionamento Ácido do Dente/métodos , Resinas Acrílicas/química , Resinas Compostas/química , Corrosão Dentária/métodos , Materiais Dentários/química , Análise do Estresse Dentário/instrumentação , Diamante/química , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Metilmetacrilatos/química , Distribuição Aleatória , Cimentos de Resina/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Fatores de TempoRESUMO
OBJECTIVE: To compare shear bond strength of different direct bonding techniques of orthodontic brackets to acrylic resin surfaces.METHODS: The sample comprised 64 discs of chemically activated acrylic resin (CAAR) randomly divided into four groups: discs in group 1 were bonded by means of light-cured composite resin (conventional adhesive); discs in group 2 had surfaces roughened with a diamond bur followed by conventional direct bonding by means of light-cured composite resin; discs in group 3 were bonded by means of CAAR (alternative adhesive); and discs in group 4 had surfaces roughened with a diamond bur followed by direct bonding by means of CAAR. Shear bond strength values were determined after 24 hours by means of a universal testing machine at a speed of 0.5 mm/min, and compared by analysis of variance followed by post-hoc Tukey test. Adhesive remnant index (ARI) was measured and compared among groups by means of Kruskal-Wallis and Dunn tests.RESULTS: Groups 3 and 4 had significantly greater shear bond strength values in comparison to groups 1 and 2. Groups 3 and 4 yielded similar results. Group 2 showed better results when compared to group 1. In ARI analyses, groups 1 and 2 predominantly exhibited a score equal to 0, whereas groups 3 and 4 predominantly exhibited a score equal to 3.CONCLUSIONS: Direct bonding of brackets to acrylic resin surfaces using CAAR yielded better results than light-cured composite resin. Surface preparation with diamond bur only increased shear bond strength in group 2.
OBJETIVO: comparar a resistência ao cisalhamento de diferentes técnicas para colagem direta de braquetes ortodônticos em superfície de resina acrílica.MÉTODOS: sessenta e quatro (64) discos de resina acrílica ativada quimicamente (RAAQ) foram divididos aleatoriamente em qautro grupos: grupo 1 = colagem com resina composta fotopolimerizável (adesivo convencional); grupo 2 = superfície abrasionada com broca diamantada e colagem com resina composta fotopolimerizável; grupo 3 = colagem com RAAQ (adesivo alternativo); grupo 4 = superfície abrasionada com broca diamantada e colagem com RAAQ. A resistência ao cisalhamento foi avaliada 24h após a colagem, utilizando-se uma máquina universal de ensaios, operando a uma velocidade de 0,5mm/min, e comparada por meio da análise de variância, seguida pelo teste post-hoc de Tukey. O índice de adesivo remanescente (IAR) foi mensurado e comparado entre os grupos por meio dos testes Kruskal-Wallis e Dunn.RESULTADOS: os grupos 3 e 4 demonstraram resistência ao cisalhamento significativamente maior do que os grupos 1 e 2. Os grupos 3 e 4 apresentaram resultados similares. O grupo 2 apresentou melhores resultados do que o grupo 1. Na análise do IAR, observou-se predominância do escore 0 para os grupos 1 e 2 e do escore 3 para os grupos 3 e 4.CONCLUSÕES: a colagem do braquete em superfície de resina acrílica utilizando-se a RAAQ apresentou melhores resultados do que a colagem com resina composta fotopolimerizável. A abrasão da superfície com broca diamantada apenas aumentou a resistência ao cisalhamento no grupo 2.
Assuntos
Animais , Gatos , Masculino , Doenças do Gato/diagnóstico , Pólipos Nasais/veterinária , Doenças do Gato/patologia , Doenças do Gato/cirurgia , Pólipos Nasais/diagnóstico , Pólipos Nasais/cirurgiaRESUMO
This study aimed to evaluate the potential correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation of the maxillary first molars. Scanned images of 104 cast models were grouped according to the severity of Class II malocclusion as follows: Group 1, 1/4 Class II malocclusion; Group 2, 1/2 Class II malocclusion; Group 3, 3/4 Class II malocclusion; and Group 4, complete Class II malocclusion. The rotation was measured using parameters described by Henry, Friel, and Ricketts, referred to as indicators 1, 2, and 3, respectively. The correlation was evaluated using the Spearman's correlation coefficient. The rotational indicators were compared using one-way analysis of variance. For all statistical analyses used p < 0.05, a positive correlation was observed between the severity of Class II malocclusion and the mesiopalatal rotation of the maxillary first molar. This correlation was statistically significant for indicator 1 between Groups 1 and 3 and for indicator 2 between Groups 1 and 4, which include cases of extreme malocclusion. In conclusion, there is a positive correlation between the severity of Class II division 1 malocclusion and the magnitude of mesiopalatal rotation in the maxillary first molars.
Assuntos
Má Oclusão Classe II de Angle/diagnóstico , Dente Molar , Rotação , Humanos , Índice de Gravidade de DoençaRESUMO
AIM: This study sought to compare the fracture resistance of three trademarked orthodontic mini-implants in the transmucosal profile region. Thirty-six mini-implants of three different brands, separated into groups I, II and III, were tested. Each group consisted of 12 mini-implants of 6 mm in length. The mean diameter and length of the transmucosal profile of the mini-implants were 1.90 and 2.0 mm in group I, 1.77 and 1.0 mm in group II and 1.50 and 1.0 mm in group III, respectively. The tests were performed on a universal testing machine in compression mode, with a 2,000 kgf load, a speed of 4.0 mm per minute and a chisel-shaped active tip, which acted cross-sectionally on the transmucosal profile. Single-criterion analysis of variance was used to compare the three brands. A significance level of 5% and test power of 80% were adopted. The mean fracture resistance achieved by the mini-implants was 172.03 ± 25.59 N for group I, 162.35 ± 30.81 N for group II and 139.69 ± 42.99 N for group III. There was no statistically significant difference in mean fracture resistance among the tested mini-implant brands. CONCLUSION: The transmucosal profile diameter does not seem to be a deciding factor in the choice of mini-implants to minimize the risk of fractures. CLINICAL SIGNIFICANCE: Although being an in vitro study it is possible to believe that this new brand has a very satisfactory resistance to fracture and enables its use with great efficiency.
Assuntos
Implantes Dentários , Procedimentos de Ancoragem Ortodôntica/instrumentação , Desenho de Aparelho Ortodôntico , Ligas , Ligas Dentárias/química , Análise do Estresse Dentário/instrumentação , Falha de Equipamento , Humanos , Teste de Materiais , Miniaturização , Estresse Mecânico , Propriedades de Superfície , Titânio/químicaRESUMO
AIM: The aim of this study was to investigate in vitro the bond strength of composite resins on enamel previously treated with whitening strips. MATERIALS AND METHODS: A total of 48 bovine incisors were allocated to four experimental groups (n = 12 each): G1 (WSC)- treated with 9.5% hydrogen peroxide whitening strips (3D White Whitestrips® Advanced Vivid/CREST); G2 (WSO)-treated with 10% hydrogen peroxide whitening strips (3D WhiteTM/Oral B); G3 (WG)-treated with 7.5% hydrogen peroxide gel with fluorine, calcium and potassium nitrate (White Class®/FGM); and G4 (C)-control not subjected to bleaching treatment. The specimens were subjected to bleaching over 2 weeks following the manufacturers' instructions. Following the elaboration of the composite resin test specimens, the samples were stored in artificial saliva and subsequently subjected to the micro-shear test using the universal testing machine (EMIC®). The bond strength values were analyzed by one-way ANOVA and Tukey's statistical test (5%). RESULTS: Significant differences were observed among the investigated groups (p < 0.05). The G3-WG exhibited greater values compared with the control group and the groups treated with strips, G1-WSC and G2-WSO. Analysis of the bond interface revealed that a large fraction of the failures occurred at the enamel-resin interface. CONCLUSION: The bond strength decreased following 14 days of treatment with bleaching strips, whereas the whitening gel with 7.5% hydrogen peroxide, calcium and fluorine increased the bond strength.
Assuntos
Resinas Compostas/química , Colagem Dentária , Materiais Dentários/química , Clareadores Dentários/química , Clareamento Dental/instrumentação , Adesividade , Animais , Cálcio/química , Bovinos , Cimentos Dentários/química , Esmalte Dentário/ultraestrutura , Análise do Estresse Dentário/instrumentação , Flúor/química , Peróxido de Hidrogênio/química , Cura Luminosa de Adesivos Dentários/métodos , Teste de Materiais , Nitratos/química , Compostos de Potássio/química , Distribuição Aleatória , Saliva Artificial/química , Resistência ao Cisalhamento , Estresse Mecânico , Propriedades de Superfície , Fatores de TempoRESUMO
OBJECTIVE: This study evaluated in vitro the mechanical changes of 0.018" (0.45 mm) and 0.016 × 0.022" (0.40 × 0.55 mm) thermoactivated nickel-titanium archwires subjected to heat treatment on their distal ends. MATERIALS AND METHODS: Ten archwires in diameters 0.018" and 0.016 × 0.022" by different manufacturers Ormco, Morelli, Orthometric and Unitek were tested. Each tested archwire had an experimental side, submitted to heat treatment, and an annealing-free control. Tests for load/deflection were performed using a universal testing machine, with temperature control in the austenitic transformation phase through tempe rature-controlled chamber. The variables showed normal distribution (Kolmogorov-Smirnov), the t-student test was applied in order to observe the difference between the experi mental and control groups. Statistical significance was set at p < 0.05. RESULTS: There were no statistically significant differences between the groups. CONCLUSION: Heat treatment carried out in the region corresponding to the first molar distal region on thermoactivated nickel-titanium archwires did not influence the load/deflection values in adjacent portion.
Assuntos
Ligas Dentárias/química , Níquel/química , Fios Ortodônticos , Titânio/química , Análise do Estresse Dentário/instrumentação , Elasticidade , Temperatura Alta , Humanos , Teste de Materiais , Desenho de Aparelho Ortodôntico , Braquetes Ortodônticos , Transição de Fase , Estresse Mecânico , Propriedades de SuperfícieAssuntos
Resinas Compostas/química , Colagem Dentária/métodos , Aparelhos Ortodônticos , Cimentos de Resina/química , Adolescente , Adulto , Falha de Equipamento , Feminino , Seguimentos , Humanos , Cura Luminosa de Adesivos Dentários/métodos , Estudos Longitudinais , Masculino , Desenho de Aparelho Ortodôntico , Estudos Prospectivos , Método Simples-Cego , Adulto JovemRESUMO
A Classe II é uma má oclusão muito frequente na população que procura o tratamento ortodôntico. Pode ser caracterizada por um desequilíbrio das estruturas dentárias e/ou esqueléticas. Dentre as opções para o tratamento desta má oclusão podemos citar o aparelho de protração mandibular (APM) que propicia alterações esqueléticas e/ou dentoalveolares. Sendo assim, este artigo se propõe expor um caso clínico de paciente portadora de má oclusão de Classe II, 2ª divisão, tratada com o APM unilateral para correção dentária e do desvio de linha média inferior.
The treatment of Class II malocclusion is frequent in seeking patients orthodontic treatment. This malocclusion is characterized by dental or skeletal disorders. Among the treatment options, the mandibular protraction appliance (MPA) is an alternative that provides skeletal and/or dentoalveolar changes. There fore this article aimed at presenting a case report of Class II division II malocclusion treated with unilateral mandibular protraction appliance for dental correction and lower midline deviation.
Assuntos
Humanos , Feminino , Adulto , Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Funcionais , Ortodontia CorretivaRESUMO
Este estudo teve como principal objetivo avaliar o uso, naatualidade, da classificação de Angle, por 37 especialistas em Ortodontia.Para essa finalidade, foi utilizado um questionário, composto de três fotosque abrangiam apenas as relações entre os dentes posteriores, sendoque, nos três casos, a relação molar apresentada era de Classe I. Oexaminador deveria obedecer à classificação da máoclusão de Angle. Naavaliação do questionário, verificou-se que aproximadamente 69% dosexaminadores classificaram o relacionamento anteroposterior entre osmolares como Classe I, enquanto que 28% apontaram ser Classe II,e 3%apontaram ser Classe III.Entre os examinadores, 27% afirmaram utilizarapenas a classificação de Angle para fins de diagnóstico, concluindo que73% não utilizam apenas o referido sistema para a mesma finalidade. Oestudo mostrou que grande parte dos profissionais avaliados conheceos conceitos de Angle, embora não os utilize como única forma dediagnóstico de má-oclusão, priorizando outros métodos.
The aim of this study was to evaluate the use, innowadays, of the Angle classification by 37 orthodontists. For thispurpose, a questionnaire was used, consisting of three photos, coveringonly the relations between the posterior teeth, whereas in all threecases, the molar relation was Class I, which the examiner should haveclassified as the malocclusion of Angle. In the assessment questionnaire,it has been found that approximately 69% of examiners classified theanteroposterior relationship between molars as Class I, while 28%indicated as Class II and 3%, as Class III. Among the examiners,27% reported to use only the Angle classification for the diagnose,thus concluding that 73% do not use only this system for the samepurpose. This study showed that most assessed professionals know theconcepts of Angle, but do not use it as the only way for the diagnosisof malocclusion, prioritizing other methods.
Assuntos
Má Oclusão/diagnóstico , Inquéritos e QuestionáriosRESUMO
This article describes the orthodontic treatment of a young woman with a Class II malocclusion and maxillomandibular prognathism. One orthodontic mini- implant was placed in the posterior area of the palate to provide anchorage for?a transpalatal arch. The force for molar distalization was applied using an elastic chain from the lever arm inserted on the transpalatal arch to the mini-implant. Two sliding jigs were applied buccally as a complement for Class II malocclusion correction. This system created an efficient mechanotherapy for maxillary molar distalization. The active treatment period was 19 months. Normal overjet and reduction of maxillomandibular prognathism were obtained, and labial balance was improved.