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INTRODUCTION: Head and neck cancer is considered one of the most common types, and its treatment includes radiotherapy, which can trigger side effects and undesirable sequelae in the oral cavity and dental tissues. OBJECTIVE: This study aimed to make an in vitro evaluation of the shear strength and failure mode of ceramic orthodontic brackets bonded with two different composites in enamel submitted to ionizing radiation. METHODS: After the study was approved by the Research Ethics Committee, 60 healthy human premolars were selected and divided into two groups, based on the absence or presence of ionizing irradiation of the enamel. The fragments were thermocycled and then randomly subdivided into two subgroups, according to the composite used for bonding the ceramic brackets (Inspire Ice - Ormco) to the enamel (n = 15): Transbond XT composite (3M), and Light Bond composite (Reliance). After 24 hours, the specimens were submitted to the shear strength test, and the failure mode was analyzed using a stereomicroscope and confocal microscopy. The shear strength data were submitted to two-way ANOVA, considering a significance level of 5%. RESULTS: The groups submitted to radiation presented lower shear strength values (4.48MPa) than those not irradiated (9.23MPa) (p< 0.001), and the tested composites were not statistically different (p= 0.078). Regarding the fracture mode, all the groups presented mostly adhesive fractures. CONCLUSION: It was concluded that ionizing radiation negatively affects the adhesion of ceramic brackets, regardless of the composite used for bonding.
Asunto(s)
Soportes Ortodóncicos , Resistencia al Corte , Cerámica/química , Resinas Compuestas , Humanos , Radiación Ionizante , Resistencia al Corte/efectos de la radiaciónRESUMEN
ABSTRACT Introduction: Head and neck cancer is considered one of the most common types, and its treatment includes radiotherapy, which can trigger side effects and undesirable sequelae in the oral cavity and dental tissues. Objective: This study aimed to make an in vitro evaluation of the shear strength and failure mode of ceramic orthodontic brackets bonded with two different composites in enamel submitted to ionizing radiation. Methods: After the study was approved by the Research Ethics Committee, 60 healthy human premolars were selected and divided into two groups, based on the absence or presence of ionizing irradiation of the enamel. The fragments were thermocycled and then randomly subdivided into two subgroups, according to the composite used for bonding the ceramic brackets (Inspire Ice - Ormco) to the enamel (n = 15): Transbond XT composite (3M), and Light Bond composite (Reliance). After 24 hours, the specimens were submitted to the shear strength test, and the failure mode was analyzed using a stereomicroscope and confocal microscopy. The shear strength data were submitted to two-way ANOVA, considering a significance level of 5%. Results: The groups submitted to radiation presented lower shear strength values (4.48MPa) than those not irradiated (9.23MPa) (p< 0.001), and the tested composites were not statistically different (p= 0.078). Regarding the fracture mode, all the groups presented mostly adhesive fractures. Conclusion: It was concluded that ionizing radiation negatively affects the adhesion of ceramic brackets, regardless of the composite used for bonding.
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abstract Odontomas are odontogenic tumors subdivided into complex type (common in the posterior mandible region) and compound type. These lesions are usually asymptomatic and diagnosed in routine examinations, are more frequent in the second decade of life. The objective of this case is to report the treatment of a patient with complex odontoma in childhood in the anterior maxilla. A nine-year-old patient sought dental care due to non-eruption of an anterior permanent tooth. After clinical examination and radiographic analysis, the diagnostic hypothesis of odontoma was confirmed. Surgical removal of the lesion and use of orthodontic appliances were indicated. After the therapeutic protocol, the case was completely resolved. Due to the absence of symptoms, many cases of odontomas are neglected. However, it is evident that the sooner diagnosed, the better the prognosis of the patient.
resumen Los odontomas son tumores odontogénicos subdivididos en tipo complejo (común en región posterior de mandíbula) y tipo compuesto. Esas lesiones generalmente son asintomáticas y diagnosticadas en pruebas de rutina; son más frecuentes en la segunda década de vida. El objetivo de este caso es el de reportar el tratamiento de un paciente con odontoma complejo de la infancia en región anterior de maxilar. Niño de 9 años acudió a la clínica odontológica a causa de la no erupción de un diente permanente anterior. Tras examen clínico y análisis radiográfico, se estableció la hipótesis diagnóstica de odontoma. Remoción quirúrgica de la lesión y uso de aparato dental fueron indicados. Después del protocolo terapéutico se hizo la resolución completa del caso. Debido a la ausencia de síntomas, muchos casos de odontomas son ignorados. Sin embargo, cuanto antes sea diagnosticado, mejor será el pronóstico del paciente.
resumo Odontomas são tumores odontogênicos subdivididos em tipo complexo (comum em região posterior de mandíbula) e tipo composto. Essas lesões geralmente são assintomáticas e diagnosticadas em exames de rotina; são mais frequentes na segunda década de vida. O objetivo deste caso é relatar o tratamento de um paciente com odontoma complexo na infância em região anterior de maxila. Paciente de 9 anos procurou a clínica odontológica devido a não erupção de um dente permanente anterior. Após exame clínico e análise radiográfica, a hipótese diagnóstica de odontoma foi confirmada. Remoção cirúrgica da lesão e uso de aparelho ortodôntico foram indicados. Após o protocolo terapêutico foi realizada resolução completa do caso. Devido à ausência de sintomas, muitos casos de odontomas são negligenciados. Entretanto, quanto antes diagnosticado, melhor será o prognóstico do paciente.
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Além da radiografia carpal, a idade esquelética do paciente recentemente tem sido estimada também através de indicadores de maturação das vértebras cervicais em telerradiografias em norma lateral. Embora as medidas cefalométricas possam serobtidas a partir de radiografias convencionais ou digitalizadas sem diferenças clínicas significantes, nenhum estudo até então pesquisou se esta afirmação é válida para análise da maturação vertebral. Este trabalho teve como objetivo comparar a avaliaçãoda maturação óssea das vértebras cervicais através dos métodos convencional e digital. A maturidade das vértebras cervicais foi estimada pelo método de Hassel e Farman a partir da observação de telerradiografias em norma lateral de 41 jovens entresete e 14 anos, de ambos os gêneros, e sem tratamento ortodôntico prévio. A avaliação das radiografias foi realizada por três examinadores aleatoriamente, tanto no negatoscópio diretamente, como no monitor após a digitalização. O teste estatístico de correlação de Spearman apresentou um alto coeficiente de correlação (r=0,845I ) entre os métodos de avaliação, com correlaçãoestatisticamente significante (p<0,0 1). Concluiu-se que a ma turação esquelética das vértebras cervicais pode ser estimada tanto em telerradiografias laterais convencionais como em imagens digitalizadas.
In addiction to hand-wrist radiography, skeletal age of patient recently has been estimated also by cervical vertebral maturation indicators in lateral cephalometric radiographs. Although cephalometric measurements can be obtained from conventionalradiographsor digitized without clinically significant differences, no study up to this time has been investigated if this affirmation is validfor analysis of lhe vertebral maturation. The aim of this study was to compare the cervical vertebrae maturation by conventional and digital methods. The cervical vertebrae maturation index was estimated by Hassel and Farman method from lateral cephalometric radiograph observation of 41 subjects between seven and 14 years, of both genders, and without previous orthodontic treatment. The evaluation of radiographs was realized by three examiners randomly in a light box directly and in amonitor screen afier digitalization. The Spearman correlation test presented a high correlation coefficient (r=O,8451) statistically significant(p<0, 01) between the methods. It was concluded that the cervical vertebrae maturation index can be estimated both inlateral cephalometric radiograph and in digitized images.