Nanoparticle loading level and properties of experimental hybrid resin luting agents.
OBJECTIVE
This study investigated the influence of nanoparticle loading level on properties of experimental hybrid resin luting agents.


METHODS
Silanated 2-μm barium borosilicate glass microparticles and 7-nm silica nanoparticles were used. Five materials were obtained by loading a photocurable Bis-GMA/TEGDMA co-monomer with a total mass fraction of 60% inorganic fillers. The mass fraction of nanoparticles was set at 0% (control), 1% (G1), 2.5% (G2.5), 5% (G5), or 10% (G10). The properties evaluated were flexural strength (σ) and modulus (E(f) ), Knoop hardness number (KHN), and film thickness (FT). Dispersion/interaction of the particles with the resin phase was assessed by scanning electron microscopy (SEM). Data were submitted to statistical analysis (5%).


RESULTS
For σ, G1 > G2.5 = G5 = G10, and control > G10. For E(f) , G2.5 > control = G1 > G5 > G10. For KHN, G5 = G10 > control = G1 = G2.5. For FT, G10 = G5 > control = G1, and G10 > G2.5. Incorporation of nanoparticles was associated with observation of clusters in the SEM analysis. The clusters were more frequent for higher nanoparticle loadings.


CONCLUSIONS
Modest incorporation of nanoparticles may improve the properties of resin luting materials. Nanofiller mass fractions above 2.5% should, however, be avoided because they may be detrimental to the properties of the resin luting agents.
School of Dentistry, Federal University of Pelotas, Rua Goncalves Chaves 457, Pelotas, Brazil.
Luciano V
LV
Habekost
Guilherme B
GB
Camacho
Giana S
GS
Lima
Fabrício A
FA
Ogliari
Glória B
GB
Cubas
Rafael R
RR
Moraes
D003799:Dental Stress Analysis; D055119:Elastic Modulus; D005898:Glass / Q000737:chemistry*; D006244:Hardness; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D053758:Nanoparticles; D018583:Pliability; D012044:Regression Analysis; D019279:Resin Cements / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry
D019279:Resin Cements; D012822:Silicon Dioxide