ABSTRACT
Objective: To evaluate the shear bond strength of passive self-ligating brackets (Tellus EX, Eurodonto) fixed to enamel using different materials and adhesive protocols. Materials and methods: Forty-eight bovine incisors were selected and divided into 6 groups according to the material and the adhesive protocol, as follows: G1 - Orthodontic resin Transbond XT, 3M Unitek (TB) associated to Single Bond 2 adhesive, 3M ESPE (SB2), G2 - TB associated with Ambar adhesive, FGM (AB), G3 - TB without application of adhesive, G4 - Orthodontic resin Orthocem, FGM (OC) associated with SB2, G5 - OC associated with AB and G6 - OC without adhesive application. The brackets were fixed following the manufacturers' instructions and stored in deionized water at 37°C for 24h. After that, the specimens were subjected to shear bond strength test (SBS) in a universal test machine (DL2000, Emic) with a crosshead speed of 0.5 mm/min and evaluated for adhesive remnant index (ARI). The data were submitted to ANOVA two criteria and Tukey's test (α = 0.05). Results: There was statistically significant difference between groups (p<0.05). The combination TB/SB2 (G1) showed significantly higher SBS values than TB/without adhesive (G3) and OC/SB2 (G4), not differing from the other groups. The lowest SBS values were observed for the TB group/without adhesive (G3), which did not differ from OC/SB2 groups (G4) and OC/without adhesive (G6). Conclusion: The use of adhesives before application of orthodontic resin promotes improvement in SBS values, except for the OC material, which can be used without adhesive association, without a significant adhesion reduction.(AU)
Objetivo: Avaliar a resistência de união ao cisalhamento de bráquetes autoligados passivos (Tellus EX, Eurodonto), fixados com diferentes materiais e protocolos adesivos. Material e metódos: Quarenta e oito incisivos bovinos foram selecionados e distribuídos em 6 grupos de acordo com o material e o protocolo adesivo, sendo: G1 - resina ortodôntica Transbond XT, 3M Unitek (TB) associada ao adesivo Single Bond 2, 3M ESPE (SB2), G2 - TB associado ao adesivo Ambar, FGM (AB), G3 - TB sem aplicação de adesivo, G4 - resina ortodôntica Orthocem, FGM (OC) associada a SB2, G5 - OC associado a AB e G6 - OC sem aplicação de adesivo. Os bráquetes foram fixados seguindo as instruções dos fabricantes e armazenados em água deionizada a 37ºC por 24h. Depois, os espécimes foram submetidos ao ensaio de resistência de união cisalhamento (RU) em máquina de ensaio universal (DL2000, Emic) à velocidade de 0,5 mm/min e avaliados quanto ao índice de remanescente adesivo (IRA). Os dados foram submetidos à análise de variância dois critérios e teste de Tukey (α=0,05). Resultados: Houve diferença estatística significativa entre os grupos (p<0,05). A combinação TB/SB2 (G1) apresentou significativamente maiores valores de RU do que TB/sem adesivo (G3) e OC/SB2 (G4), não diferindo dos demais grupos. Os menores valores RU foram observados para o grupo TB/sem adesivo (G3), o qual não diferiu dos grupos OC/SB2 (G4) e OC/sem adesivo (G6). Conclusão: O uso de adesivos antes da aplicação da resina ortodôntica promove melhora nos valores de RU, exceto para o material OC, o qual pode ser utilizado sem associação a adesivo, sem que haja redução significativa da adesão.(AU)
Subject(s)
Animals , Cattle , Orthodontic Brackets , Resin Cements , Shear StrengthABSTRACT
Introduction:Dental hypomineralization such as dental fluorosis has increased in recent times leading to unaesthetic appearance of teeth. There are different treatment possibilities to improve the aesthetic appearance of hypomineralized enamel described in dental literature. The enamel microabrasion has been a feasible alternative, since it is a fast, safe, conservative, and easy to perform, which promotes good esthetic results. Moreover, this technique is a conservative method that improves the appearance of the teeth by restoring bright and superficial smoothness, without causing significant structural loss. The association of different techniques, such as direct composite resin, can provide good esthetic outcomes, but the etiology, intensity, and depth of stain should be considered to minimize dental structure loss. Objective: To describe an easy technique for managing dental fluorosis using enamel microabrasion in association with direct composite resin. Case report: A mixture of hydrochloric acid and silicon carbide was applied according the manufacturer's instructions. Subsequently, a direct composite resin was applied over the areas where the opacities were more evident. This conservative approach may be considered an interesting alternative treatment to remove fluorosis staining and to improve aesthetic appearance. Conclusion: enamel microabrasion combined with direct composite resin is a conservative and safe alternative method to treat enamel opacities from dental fluorosis. Therefore, this management provides satisfactory aesthetic results for the patient's smile.