Comparative Analysis of Shear Bond Strength of Steel and Ceramic Orthodontic Brackets Bonded with Six Different Orthodontic Adhesives / Análisis Comparativo de la Resistencia al Corte de Brackets de Ortodoncia de Acero y Cerámica Unidos con Seis Adhesivos de Ortodoncia Diferentes

ABSTRACT: Orthodontic accessories bonding in tooth enamel has been a critical step since the introduction of direct bonding techniques due to the importance of bracket stability. The aim of this study was to evaluate adhesion strength of different adhesive systems used for bracket bonding on dental surface. The present in vitro study was made from the analysis of shear strength of steel and ceramic brackets bonding with six different types of orthodontic adhesives. The brackets were bonded to 120 human extracted first premolar teeth with Orthocem®, Orthocem® + Ambar Universal® primer, Orthobond Plus®, Biofix®, Transbond XT®, Ortholink VLC®. Shear strength tests were performed on a universal testing machine EZ-Test-Shimadzu® and the data were analyzed using ANOVA test with Post-Hoc Bonferroni and 95 % statistical significance (p <0.05). Transbond XT® and Ortholink VLC® resin values showed greater shear resistance for steel brackets bonding and Transbond XT® and Orthobond Plus® adhesives showed better adhesion results for ceramic brackets bonding.

RESUMEN: La unión de accesorios de ortodoncia en el esmalte dental ha sido un paso crítico desde la introducción de las técnicas de unión directa debido a la importancia de la estabilidad del soporte. El objetivo de este estudio fue evaluar la fuerza de adhesión de diferentes sistemas adhesivos utilizados para la unión de brackets en la superficie dental. El presente estudio in vitro se realizó a partir del análisis de la resistencia al corte de brackets de acero y de cerámica unidos con seis tipos diferentes de adhesivos de ortodoncia. Los brackets se unieron a 120 primeros premolares extraídos con los adhesivos Orthocem®, Orthocem® + Ambar Universal® primer, Orthobond Plus®, Biofix®, Transbond XT®, Ortholink VLC®. Las pruebas de resistencia al corte se realizaron en una máquina de prueba universal EZ-Test-Shimadzu® y los datos se analizaron usando la prueba ANOVA con Bonferroni Post-Hoc y 95 % de significación estadística (p <0,05). Los valores de resina Transbond XT® y Ortholink VLC® mostraron una mayor resistencia al corte para la unión de brackets de acero y los adhesivos Transbond XT® y Orthobond Plus® mostraron mejores resultados de adhesión para la unión de brackets cerámicos.

Evaluation of Symptoms of Temporomandibular Disorders in Orthodontic Appliance Users / Evaluación de los Síntomas de Trastornos Temporomandibulares en los Usuarios de Aparatos Ortodónicos

ABSTRACT: Temporomandibular joint disorders (TMD) are multifactorial pathological conditions that can generate significant impacts on quality of life of individuals. Orthodontics treatments have been discussed in the current literature due to its possible association with the development of TMD. The aim of this study was to evaluate the relationship between the use of fixed orthodontic appliances and the symptoms of TMD. This cross-sectional study was performed with a sample of 336 undergraduate dental students that answered a structured questionnaire about symptoms of TMD. The sample was paired for sex and use of fixed orthodontic appliances. The results highlighted that the most prevalent symptoms of TMD were headaches (21.4 %, n=72), temporomandibular joint noises (21.4 %, n=72) and head and/or neck pain (20.0 %, n=67). The most of sample, 60.4 % (n=203), showed mild TMD symptomatology. No statistical association was observed between the use of orthodontic appliances and TMD symptoms (p=0.121). It can be suggested that the use of fixed orthodontic appliances is not a factor associated with the symptoms of TMD. Still, it is possible to conclude that the prevalence of light TMD symptoms in dentistry students is high.

RESUMEN: Los trastornos de la articulación temporomandibular (TTM) son un grupo de patologías multifactoriales que pueden generar impactos significativos en la calidad de vida de las personas. Los tratamientos de ortodoncia se han discutido en la literatura actual debido a su posible asociación con el desarrollo de TTM. Evaluar la relación entre el uso de aparatos de ortodoncia fijos y los síntomas de TTM. Material y métodos: este estudio transversal se realizó con una muestra de 336 estudiantes de odontología que respondieron un cuestionario estructurado sobre los síntomas de TTM. La muestra fue emparejada por género y uso de aparatos de ortodoncia fijos. Los resultados destacaron que los síntomas más prevalentes de TTM fueron cefaleas (21,4 %, n=72), ruidos de la articulación temporomandibular (21,4 %, n=72) y dolor de cabeza y/o cuello (20,0 %, n=67). La mayor parte de la muestra, 60,4 % (n=203), presentó síntomas leves de TTM. No se observó asociación estadística entre el uso de aparatos de ortodoncia y los síntomas de TTM (p=0,121). Se puede sugerir que el uso de aparatos de ortodoncia fijos no es un factor asociado con los síntomas de TTM. Aun así, es posible concluir que la prevalencia de síntomas leves de TTM en estudiantes de odontología es alta.

Ex vivo Analysis of Three Electronic Apex Locators Accuracy with Different Settings.

Aims: The correct determination of a root canal length is a fundamental step for an adequate chemical-mechanical preparation and consequently, for a successful endodontic treatment. Electronic apex locators (EAL) were developed to provide fast and reliable working lengths. The aim of the present study was to analyze the accuracy of the Root ZX II, RomiApex A-15, and SmarPex EAL’s to determine the location of apical constriction, with and without the instructions recommended by the manufacturers. Methodology: Fifteen mandibular premolars were randomly selected and root canals were accessed. The real canal length was determined by introducing a #15 K-file until the tip was visualized in the apical foramen, using 40x magnification of an operative microscope. In the sequence, the teeth were inserted in plastic flasks containing floral foam soaked in 0.9% saline solution. The root canals were filled with 1% sodium hypochlorite and the electronic measures were obtained with the selected devices until the “0.0” or the last green bar mark, as showed in devices display, and as per the manufacturers settings recommendation. The data were submitted to statistical analysis with the Friedman and Wilcoxon tests with a 0.05% significance level (p < 0.05). Results: All devices were similar (p > 0.05) and showed precise and acceptable measurements at both times. Without manufacturers setting recommendation, the Root ZX II was the EAL that presented the greater percentage of coincidences with the real teeth length measures (73.33%), followed by the RomiApex A-15 (66.66%) and the SmarPex (40%). After performing the recommended settings the Root ZX II and the SmarPex presented 86.66% of coincidence with the real length, however, only the SmarPex device enhanced the mean precision with the real length (p < 0.05). Conclusion: Considering a clinically acceptable average error of ±0.5 mm, all devices were effective in determining the measurement until the apical constriction. Although, there were no statistical significant difference with and without manufacturers instruction, for Root ZX II, the performance was better when manufacturer instructions were followed.

Long-term cytotoxic effects of contemporary root canal sealers

Objectives: The aim of the present study was to investigate the effects of root canal sealers on the cytotoxicity of 3T3 fibroblasts during a period of 5 weeks. Material and Methods: Fibroblasts (3T3, 1×105 cells per well) were incubated with elutes of fresh specimens from eight root canal sealers (AH Plus, Epiphany, Endomethasone N, EndoREZ, MTA Fillapex, Pulp Canal Sealer EWT, RoekoSeal and Sealapex) and with elutes of the same specimens for 5 succeeding weeks after immersing in simulated body fluid. The cytotoxicity of all root canal sealers was determined using the MTT assay. Data were analyzed using ANOVA and Tukey's test. Results: RoekoSeal was the only sealer that did not show any cytotoxic effects (p<0.05). All the other tested sealers exhibited severe toxicity initially (week 0). MTA Fillapex remained moderately cytotoxic after the end of experimental period. Toxicity of the other tested sealers decreased gradually over time. The evaluated root canal sealers presented varying degrees of cytotoxicity, mainly in fresh mode.Conclusions: RoekoSeal had no cytotoxic effect both freshly mixed and in the other tested time points. MTA Fillapex was associated with significantly less cell viability when compared to the other tested root canal sealers.

Acuidade do Root ZX II utilizando limas de aço inoxidável e de níquel-titânio

Objetivo: avaliar in vitro a eficiência do localizador apical eletrônico (LAE) Root ZX II em determinar o comprimento de trabalho, utilizando limas manuais de aço inoxidável,limas manuais de níquel-titânio e limas rotatórias de níquel-titânio. Métodos: foram utilizados 20 dentes humanos unirradiculares (incisivos centrais retos). O comprimento real do dente (CRD) foi determinado através da inserção de um lima #15 até que a sua ponta fosse visível no forame apical, utilizando uma ampliação de 4x. A lima foi removida do canal e seu comprimento foi medido com um paquímetro digital. Para as medições eletrônicas,as amostras foram fixadas em uma embalagem de vidro com cobertura plástica, contendo solução salina a 0,9%. As medições foram realizadas utilizando-se o Root ZX II, com lima #15 de aço inoxidável, lima manual de níquel-titânio e lima rotatória Mtwo. As limas foram acopladas ao LAE e as medições foram monitoradas até que o LAE indicasse o valor “zero”. Os valores correspondentes à diferença entre o CRD e a medição eletrônica foram gravados e submetidos à análise de variância(ANOVA) e o teste Tukey (α=0,05). Resultados: não houve diferença estatisticamente significativa (p<0,05)entre as limas testadas. Conclusão: a partir do presente estudo, constatou-se que o LAE Root ZX II foi eficaz,mostrando-se um método confiável, e que nenhuma interferência significativa na sua leitura foi detectada ao se utilizar as diferentes limas

Evolução temporal da dengue no município de Ribeirão Preto, São Paulo, 1994 a 2003 / Temporal evolution of dengue fever in Ribeirão Preto, São Paulo State, 1994 - 2003

Este estudo caracteriza-se epidemiológico-descritivo com objetivo de descrever a evolução temporal dos casos de dengue em Ribeirão Preto, São Paulo, no período de 1994 a 2003, segundo mês de ocorrência e sexo. Os dados foram obtidos junto às fichas de notificação compulsória fornecidas pela Vigilância Epidemiológica da Secretaria Municipal de Saúde do município. Foram obtidos os coeficientes de incidência por 100.000 habitantes, segundo estimativas populacionais do Instituto Brasileiro de Geografia e Estatística. O município viveu uma epidemia de dengue no ano de 2001, quando o coeficiente de incidência chegou a 619,65 casos/100.000 habitantes, sendo que dentre os 5.553 casos encontrados no período estudado, 0,07 por cento ocorreram no ano de 1994, 3,68 por cento em 1995, 4,52 por cento em 1996, 2,40 por cento em 1997, 1,82 por cento em 1998, 5,73 por cento em 1999, 3,75 por cento em 2000, 57,37 por cento em 2001, 6,25 por cento em 2002 e, 14,39 por cento em 2003 . Os meses do ano de maior ocorrência da doença foram de janeiro a maio. Em relação à variável sexo, a proporção entre o número de casos foi de aproximadamente 1:1, mostrando pequenas flutuações de casos de dengue entre homens e mulheres, para todo período estudado. Os resultados apontam a necessidade do desenvolvimento de estudos sobre a temática e reforçam o papel das instituições de ensino na questão da dengue no nosso país.

This epidemiological-descriptive study aimed to describe the temporal evolution of dengue cases in Ribeirão Preto, São Paulo State, between 1994 and 2003, according to month of occurrence and gender. Data were obtained from the compulsory notification forms provided by the Epidemiological Surveillance service of the Ribeirão Preto Municipal Health Secretary. We obtained incidence coefficients per 100,000 inhabitants, according to population estimates by the Brazilian Institute of Geography and Statistics. The city experienced a dengue epidemic in 2001, when the incidence coefficient reached 619.65 cases/100,000 inhabitants. We found 5553 cases during the study period, 0.07 percent of which occurred in 1994, 3.68 percent in 1995, 4.52 percent in 1996, 2.40 percent in 1997, 1.82 percent in 1998, 5.73 percent in 1999, 3.75 percent in 2000, 57.37 percent in 2001, 6.25 percent in 2002 and 14.39 percent in 2003. January to May were the months with the highest occurrence levels. As to the gender variable, we found a proportion of approximately 1:1, showing small fluctuations between men and women for dengue cases during the entire study period. Results indicate the need to study the theme and reinforce the role of teaching institutions to tackle dengue in Brazil.