Effect of substrate and adhesive system type on composite resin restorations

Introduction: Although it is possible to obtain a reliable bond between enamel and composite resin, the ideal bonding method of composite resin to dentin still needs to be developed. Variables such as the type of adhesive system used and type of dentin substrate can influence on the adhesion. Objective: The purpose of this study was to compare the shear bond strength of composite resin restorations to human and bovine dentin using three adhesive systems. Material and methods: Fifteen human third molars sectioned into two halves and 30 bovine incisors were cut into blocks (4x4mm), embedded in acrylic resin and ground flat to expose the dentin. The specimens were randomly divided into six groups (n = 10): group 1 - human dentin using Scotchbond Multi-Purpose; group 2 - human dentin using Adper Single Bond 2; group 3 - human dentin using Adper Prompt L-Pop; group 4 - bovine dentin using Scotchbond Multi-Purpose; group 5 - bovine dentin using Adper Single Bond 2; group 6 - bovine dentin using Adper Prompt L-Pop. After composite resin restoration procedure, the specimens were stored into distilled water for 24h at 37ºC and then submitted to the shear test using a universal testing machine. The failure patterns were examined microscopically and classified as adhesive, cohesive in resin, cohesive in dentin or both, and mixed. The ANOVA (two-way) and Tukey's post hoc were used. Chi-square test for independence was used for analysis of failure mode. The significance level was set at 5%. Results: A significant difference in shear bond strength was observed among adhesive systems (p = 0.031), with higher values for one-bottle adhesive (8.87±2.72) and lower for self-etching (6.38±3.15), and between the two types of substrate (p = 0.018), with higher values for human dentin. However, there was no significant difference for the adhesive system/substrate interaction (p = 0.11). Adhesive failure was the predominant failure mode for all adhesive systems and for the two substrates. Conclusion: Shear bond strength was different between human and bovine substrates and for the adhesive system used.

Odontogenic cysts in children and adolescents: a 21-year retrospective study

Aim: To investigate the distribution of odontogenic cysts in patients aged 0 to 18, referred toDepartment of Pathology, University Hospital of the Federal University of Maranhão, Brazil, todetermine the most common types of lesions and their distribution according to gender and anatomicalsite involved. Methods: Histopathological data were collected from a database of lesions classifiedas odontogenic cysts that were indicated for surgical removal and histopathological analysis. Datawere subjected to descriptive analysis. Results: Thirty cases of odontogenic cysts were identified,and dentigerous cysts were the most frequent (n=17). Most occurrences were in males (66.7%)and the most frequent site was the posterior mandible (73.3%). Conclusions: Odontogenic cystsin children and adolescents are mostly developmental cysts, especially dentigerous cysts, occurringpredominantly in males, with a predilection for the posterior mandible.

Resistência de união de dois sistemas adesivos ao esmalte bovino / Bond strength of two adhesive systems to bovine enamel

Objetivo: avaliar a resistência de união às forças de cisalhamento de dois sistemas adesivos, um convencional e um autocondicionante, em esmalte de dente bovino. Métodos: trinta e duas placas de esmalte bovino (16mm2) foram confeccionadas e divididas aleatoriamente, em dois grupos experimentais (n=16): G1-adesivo convencional Magic Bond (Vigodent) e G2- adesivo autocondicionante AdheSE DC Activator (Ivoclar Vivadent). A área de adesão foi delimitada em 4mm de diâmetro, e o sistema adesivo, aplicado de acordo com as recomendações do fabricante. Em seguida, um de cilindro de resina composta de 2x2mm (diâmetro x altura) foi confeccionado por placa. As amostras foram armazenadas em soro fisiológico por 2 dias, VG a 37°C e submetidas a ensaio mecânico de resistência de união ao cisalhamento (0,5mm/min - TIRAtest 2420). Foi utilizada estatística descritiva e teste t de Student (5%). Resultados: o adesivo Magic Bond (11,2 ± 1,9) apresentou maior média de resistência de união que o adesivo AdheSE DC Activator (4,4 ± 1,5). Conclusão: os dados sugerem que a resistência de união ao esmalte bovino é maior nos sistemas adesivos convencionais que nos autocondicionantes.

Objective: This study evaluated the shear bond strength of two adhesive systems, one etch-and-rinse adhesive and one self-etching adhesive, in bovine tooth enamel. Methods: Thirty-two plates of bovine enamel (16mm2) were fabricated and randomly divided into two experimental groups (n=16): G1- etch-and-rinse adhesive Magic Bond (Vigodent) and G2- self-etching adhesive AdheSE DC Activator (Ivoclar Vivadent). The adhesion area was enclosed in 4mm of diameter and adhesive system applied according to the manufacturer's recommendations. Then a cylinder of composite resin (2mm diameter x 2mm height) was made by the plate. The samples were stored in saline solution for 2 days at 37°C and subjected to mechanical testing of shear bond strength (0,5mm/min - TIRAtest 2420). Was used descriptive statistics and Student's t test (5%). Results: Magic Bond (11.2 ± 1.9) showed higher mean strength than AdheSE DC Activator (4.4 ± 1.5). Conclusion: The data suggest that the bond strength to bovine enamel is higher in etch-and-rinse adhesives than in self-etching adhesives.

Alterações gengivais em área de restaurações classe II com excesso de material restaurador / Gingival alterations in areas adjacent to overhanging Class II restorations

Introdução: As restaurações proximais ainda representam um desafio na prática da Odontologia Restauradora. Margens com excesso de material são frequentemente observadas, favorecendo o acúmulo de placa na região e interferindo na manutenção de uma gengiva saudável. Objetivo: O objetivo deste trabalho foi verificar as alterações gengivais em áreas de restaurações classe II com excesso de material restaurador bem como detectar a prevalência de restaurações classe II com excessos de material restaurador em duas Clínicas do Curso de Odontologia da Universidade Federal do Maranhão. Materiais e Métodos: Foram selecionados 20 pacientes por meio de exame clínico e radiográfico, nos quais foram analisados excessos de material restaurador, profundidade clínica de sondagem e sangramento gengival nas áreas adjacentes às restaurações proximais. Resultados: Foram encontradas 55 superfícies proximais restauradas com amálgama ou resina composta, as quais demonstraram um número relativamente alto de superfícies com excessos (50,9%), aumento da profundidade clínica de sondagem e presença de sangramento gengival nas áreas adjacentes a essas restaurações. Conclusões: Os autores concluíram que os excessos de material restaurador representam danos aos tecidos gengivais, estando diretamente relacionados ao aumento da profundidade de sondagem e sangramento gengival.

Introduction: The proximal restorations still represent a challenge in the practice of restorative dentistry. Overhanging restorations are frequently observed, favoring the accumulation of plaque in the region and may interfere in the maintenance of healthy gums. Objective:The aim of this study was to detect the prevalence of overhanging class II restorations and the relationship with gingival alterations in two Dental Clinics at the School of Dentistry of Federal University of Maranhão. Materials and Methods: Twenty patients were assessed by clinical and radiographic examination in order to observe overhanging restorations, probing pocket depth and gingival bleeding in the areas adjacent to the proximal restorations. Results: There were found 55 proximal surfaces restored with amalgam or composite resin which showed a relatively high number of overhanging surfaces (50,9%), increased probing pocket depth and presence of gingival bleeding in the adjacent areas to the restorations. Conclusions: Authors had concluded that overhanging restorative material represents damage to gingival tissues, being directly related to increased periodontal pocket depth and gingival bleeding.

Reconstrução em dentes anteriores endodonticamente tratados: técnica direta e pino de fibra de vidro / Reconstruction in endodontically treated previous teeth: direct technical and glass fiber pin

Dentes endodonticamente tratados são menos resistentes a fraturas. Quando grande parte da estrutura coronária desses dentes encontra-se destruída, faz-se necessário o uso de retento- res intra-radiculares, a fim de promover melhor distribuição de forças ao remanescente dental e retenção do material restaurador. O presente relato aborda a reconstrução em dentes anteriores endodonticamente tratados utilizando pino de fibra de vidro e técnica direta com resina com- posta. Os pinos de fibra de vidro tornaram-se material de escolha para reconstrução de dentes despolpados, pois apresentam vantagens como módulo de elasticidade próximo ao da dentina, ausência de corrosão, facilidade de inserção e remoção e adequada estética.

Endodontically treated teeth are less resistant to fracture. When much of the structure of coronary teeth is destroyed, it is necessary the use of post and core technique in order to promote better distribution of forces to the remaining tooth and retention of restorative material. This report deals with the reconstruction in endodontically treated previous teeth using glass fiber pin and direct technique with composite resin. The pins of glass fibers become material of choice for reconstruction of nonvital teeth, since they have advantages such as modulus of elasticity near the dentin, no corrosion, ease of insertion and removal and appropriate aesthetics.

Atendimento odontológico em pacientes com hemofilia e doença de von Willebrand / Dental care in patients with hemophilia and von Willebrand disease

Os pacientes com transtornos de coagulação sanguínea constituem um grupo que requer atenção e cuidados especiais na prática odontológica. A hemofilia e a doença de von Willebrand são as mais comuns das coagulopatias hereditárias e devem ser detectadas antes que qualquer tratamento odontológico seja realizado. Uma boa anamnese, associada a um bom exame físico e bucal podem ajudar na detecção dessas patologias. O cirurgião-dentista deve estar preparado para oferecer o tratamento adequado a esses pacientes, o qual depende da severidade da doença e do tipo de procedimento a ser realizado. Procedimentos menos invasivos geralmente não necessitam de cuidados especiais e podem ser realizados rotineiramente, desde que alguns cuidados básicos sejam tomados. Cirurgias e técnicas anestésicas de bloqueio do nervo alveolar inferior devem ser realizadas com maior precaução, a fim de minimizar os riscos de sangramento e outras complicações. O hematologista deve ser consultado sempre que qualquer tratamento invasivo for planejado.