Effectiveness of different orthodontic adhesives and a universal bonding resin on the bond strength of brackets to different ceramics / Eficácia de diferentes adesivos ortodônticos e uma resina de ligação universal na resistência adesiva de bráquetes à diferentes cerâmicas

Objective: The aim of this study was to evaluate the effectiveness of different adhesives on the shear bond strength (SBS) of brackets bonded to different ceramic materials. Material and Methods: Fifty disk-shaped specimens were produced from lithium disilicate (IPS e.max CAD) and monolithic zirconia (Cercon) materials. Each specimen was polished with a three-step diamond polishing system. The polished ceramic surfaces were conditioned with universal bonding resin (Assure Plus) without pre-treatment, except for two specimens. Central brackets were bonded onto different ceramic specimens with different adhesives as follows: group 1: conventional adhesive onto the lithium disilicate; group 2: one-step adhesive onto the lithium disilicate; group 3: conventional adhesive onto the monolithic zirconia; group 4: one-step adhesive onto the monolithic zirconia. After thermal cycling, the specimens were subjected to the SBS test. The adhesive remnant index (ARI) scores were also recorded to evaluate bond failure type. Kruskal­Wallis and Mann-Whitney U tests were used for statistical analysis. Results: There were statistically significant differences among the SBS values (p˂0.05). The monolithic zirconia group with universal bonding resin and conventional orthodontic adhesive demonstrated the highest SBS value (6.34 MPa) and ARI scores. The lithium disilicate group showed the lowest SBS value (2.17 MPa) with the same protocol. No adhesive remained on the lithium disilicate specimens. Conclusion: One-step adhesive and universal bonding resin combination should not be considered as an alternative for lithium disilicate and monolithic zirconia restorations. Conventional adhesive and universal bonding resin application can be effective on non-pretreated ceramic surfaces during orthodontic bonding (AU)

Objetivo: o objetivo deste estudo foi avaliar a eficácia de diferentes adesivos na resistência ao cisalhamento (SBS) de bráquetes colados a diferentes materiais cerâmicos. Material e métodos: Cinquenta espécimes em forma de disco foram produzidos a partir de materiais de dissilicato de lítio (IPS e.max CAD) e zircônia monolítica (Cercon). Cada amostra foi polida com um sistema de polimento de diamante de três passos. As superfícies cerâmicas polidas foram condicionadas com resina de ligação universal (Assure Plus) sem pré-tratamento, exceto para dois corpos-de-prova. Bráquetes centrais foram colados em diferentes corpos de prova cerâmicos com diferentes adesivos da seguinte forma: grupo 1: adesivo convencional sobre dissilicato de lítio; grupo 2: adesivo de uma etapa sobre o dissilicato de lítio; grupo 3: adesivo convencional sobre zircônia monolítica; grupo 4: adesivo de uma etapa sobre a zircônia monolítica. Após a ciclagem térmica, os corpos-de-prova foram submetidos ao teste SBS. Os escores do índice de remanescente adesivo (ARI) também foram registrados para avaliar o tipo de falha de adesão. Os testes U de Kruskal-Wallis e Mann-Whitney foram usados para análise estatística. Resultados: Houve diferenças estatisticamente significativas entre os valores de SBS (p˂0,05). O grupo de zircônia monolítica com resina de colagem universal e adesivo ortodôntico convencional demonstrou o maior valor de SBS (6,34 MPa) e escores de ARI. O grupo de dissilicato de lítio apresentou o menor valor de SBS (2,17 MPa) com o mesmo protocolo. Nenhum adesivo permaneceu nas amostras de dissilicato de lítio. Conclusão: A combinação de adesivo de uma etapa e resina de ligação universal não deve ser considerada como uma alternativa para restaurações de dissilicato de lítio e zircônia monolítica. A aplicação de adesivo convencional e resina de colagem universal podem ser eficazes em superfícies de cerâmica não pré-tratadas durante a colagem ortodôntica (AU)

Effect of a desensitizer on microtensile bond strength of different adhesives / 대한치과보존학회지

This study evaluated the influence of a desensitizer(MS coat) on microtensile bond strength of different adhesives: a three-step adhesive(All-Bond 2), a two-step adhesive(Single Bond), a one-step adhesive(One-up Bond F). Non-caries extracted human molars were used. Dentin surface was obtained by horizontal section on midportion of crown using a water-cooled low speed diamond saw. Teeth were randomly divided into 6 group. AMO(MS coat + All Bond)-, SMO(MS coat + Single Bond)- and OMO(MS coat + One-up Bond F)-dentin surface were treated with 17% EDTA before bonded adhesive. AMX-, SMX- and OMX-dentin surface were bonded with All-Bond 2, Single Bond and One-up Bond F, respectively, with no previous treatment with MS coat and 17% EDTA. About 1cm high resin composite(Z-250(TM)) were incrementally build-up on the treated surface. The specimens for the microtensile test were serially sectioned perpendicular to the adhesive layer to obtain 0.7x0.7 mm sticks. 30 sticks were prepared from each group. After that, tensile bond strength for each stick was measured with Microtensile Tester at a 1mm/min crosshead speed. Fractured dentin surfaces were observed under the SEM. The results were statistically analysed by using a One-way ANOVA and Tukey's test(p<0.05). Value in MPa were: AMO-44.35+/-13.21; SMO-39.35+/-13.32; OMO-31.07+/-10.25; AMX-49.22+/-16.38; SMX-56.02+/-13.35; OMX-72.93+/-16.19. Application of MS coat reduced microtensile bond strengths of both Single Bond and One-up Bond F, whereas microtensile bond strengths of All-Bond 2 were not affected significantly.