O objetivo deste estudo foi investigar a influ??ncia da incorpora????o de nanopart??culas e o uso de silano (TSPM), mon??mero ??cido fosfatado (PAM) ou mon??mero ??cido carboxilado (CAM) como agentes de uni??o nas propriedades de cimentos resinosos experimentais. Uma matriz resinosa fotopolimeriz??vel modelo foi desenvolvida com 50% de Bis-GMA e 50% de TEGDMA. Para observar o comportamento da incorpora????o de nanopart??culas, cinco cimentos resinosos experimentais foram preparados pela adi????o de 60% (em massa) de micropart??culas de b??rio borosilicato de vidro (2μm) e nanopart??culas de s??lica coloidal (7nm). As nanopart??culas foram utilizadas nas seguintes propor????es (em massa): 0 (controle), 1 (G1), 2.5 (G2.5), 5 (G5) e 10% (G10). Para estudar a influ??ncia dos agentes de uni??o, 60% (em massa) de part??culas inorg??nicas (59/1 de micro/nanopart??culas) de vidro de Ba-B-Al-Si e s??lica coloidal, cobertas com 5% de TSPM, PAM ou CAM, foram acrescidas ?? matriz resinosa; o grupo controle foi composto por part??culas n??o tratadas. As propriedades avaliadas foram resist??ncia flexural (), m??dulo de elasticidade (Ef), n??mero de dureza Knoop (KHN) e espessura de pel??cula (FT).A dispers??o/intera????o das part??culas com a fase resinosa foi avaliada com microsc??pio eletr??nico de varredura (MEV). O grau de convers??o (DC) foi avaliado somente para estudar a influ??ncia dos diferentes agentes de uni??o. Os dados foram submetidos ?? an??lise estat??stica (5%). Resultados para incorpora????o de nanopart??culas: para , G1 > G2.5 = G5 = G10 e controle > G10. Para Ef, G2.5 > controle = G1 > G5 > G10. Para KHN, G5 = G10 > controle = G1 = G2.5. Para FT, controle = G1 < G5 = G10 e G2.5 < G10. Nas an??lises em MEV, a presen??a de aglomerados foi associada ?? incorpora????o de nanopart??culas. Resultados para a utiliza????o de diferentes agentes de uni??o: para e Ef, TSPM > CAM > controle > PAM. Para KHN, TSPM > CAM > PAM = controle. Para FT, TSPM < controle < CAM < PAM. As an??lises em MEV revelaram aglomerados de nanopart??culas em todos os grupos e melhor intera????o entre as fases org??nica/inorg??nica para TSPM e CAM. N??o foram observadas diferen??as para o DC. Os resultados demonstraram que a incorpora????o moderada de nanopart??culas de s??lica silanizada pode beneficiar as propriedades dos cimentos resinosos h??bridos. Entretanto, propor????es de nanopart??culas acima de 2,5% possuem um efeito prejudicial nas propriedades destes cimentos, e seu aumento est?? associado com o aumento da presen??a de aglomerados. O uso de TSPM gerou cimentos com melhores propriedades quando comparado ao uso de mon??meros ??cidos, o CAM demonstrou melhor desempenho que o PAM. O uso do PAM gerou cimentos com propriedades inferiores a cimentos sem a utiliza????o de agentes de uni??o.The objective of this study was to investigate the influence of nanoparticle loading and the use of silane (TSPM), phosphate (PAM) or carboxylic (CAM) methacrylates as coupling agents on key properties of experimental resin luting agents. An experimental photocurable resin blend composed with 50 wt% of Bis-GMA and 50 wt% of TEGDMA was obtained. To study the influence nanoparticle loading, five different experimental resin luting agents were prepared with a total mass fraction of 60% of inorganic fillers. Silanated 2-μm barium borosilicate glass microparticles and 7-nm silica nanoparticles were used; the mass fraction of nanoparticles was set at 0 (control), 1 (G1), 2.5 (G2.5), 5 (G5) and 10% (G10). To study the influence of coupling agents, the resin blend was loaded with a 60% mass fraction of inorganic fillers (59/1 mass ratio of micro/nanoparticles) of Ba-B-Al-Si glass and colloidal silica coated with 5 wt% of TSPM, PAM or CAM; no filler treatment was performed in the control group. The properties evaluated were flexural strength () and modulus (Ef), Knoop hardness number (KHN), and film thickness (FT). Dispersion/interaction of particles with the resin phase was assessed by scanning electron microscopy (SEM).The degree of conversion (DC) was evaluated only to study the influence of coupling agents. Data were submitted to statistical analysis (5%). Results for nanoparticle loading: for , G1 > G2.5 = G5 = G10, and control > G10. For Ef, G2.5 > control = G1 > G5 > G10. For KHN, G5 = G10 > control = G1 = G2.5. For FT, control = G1 < G5 = G10, and G2.5 < G10. Incorporation of nanoparticles was associated with observation of clusters in the SEM analysis. Results for different coupling agents: for  and Ef, TSPM > CAM > control > PAM. For KHN, TSPM > CAM > PAM = control. For FT, TSPM < control < CAM < PAM. The SEM analysis revealed clustering of nanoparticles for all groups and better interaction between the organic-inorganic phases for TSPM and CAM. No significant differences in DC were observed. The results demonstrated that moderate incorporation of silanated silica nanoparticles may improve the properties of hybrid resin cements. However, mass fraction above 2.5% had a detrimental effect on the luting agent properties and the increase of clusters is associated with the increase of nanoparticles. The use of TSPM generated agents with improved properties as compared with the acidic methacrylates, with CAM showing better performance than PAM. The use of PAM generated agents with properties usually poorer compared with the material with no coupling agent
