Naslov
Nanoparticle Incorporation Into Conventional Glass Ionomer Cements

Autori
Gjorgievska, Elizabeta ; Miletić, Ivana ; Coleman, Nichola J ; Nicholson, John W:

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
Journal of Dental Research / - , 2016, X-x

Skup
IADR/PER kongresa, Jeruzalem, Izrael

Mjesto i datum
Jeruzalem, Izrael, 20.09.2016. - 22.09.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
GIC ; nanoparticles

Sažetak
Conventional glass ionomer cements (GIC) have been introduced in the early 1970-ies by Wilson and Kent. They are based on a mixture of carboxylic acids, usually polyacrylic acid or their copolymers, inorganic fillers (calcium-aluminum- silicate glass) and distilled water and set by an acido-base reaction. GICs advantages include adhesion to moist teeth, anticariogenic properties due to the release of fluoride, thermal compatibility with tooth enamel, biocompatibility and low toxicity. The main drawbacks of the conventional GICs are low fracture strength, toughness and low wear resistance. The new generation of conventional GICs, the so-called high-viscosity GICs, have superior physical properties compared with the previous ones3, but they still need improvement. The present study attempts to improve these materials by incorporation of different types of nanoparticles into two different commercial GICs. Two commercially available highly-viscous GICs were used in the study: ChemFil®Rock (DENTSPLY DeTrey, Konstanz, Germany) and GC EQUIA™Fil (GC Europe N.V., Leuven, Belgium). Four groups consisting of 18 samples were prepared for each material by mixing the GICs in a capsule mixer according to the manufacturers’ instructions. The first group served as a control (without addition of nanoparticles), whereas the other three groups were modified by incorporation of aluminum oxide, zirconium oxide and titanium dioxide nanoparticles ; each at 2, 5 and 10wt%. The nanoparticles were previously characterized by XRD 4 and mixed into the mixed cement by spatulation on a ceramic tile to obtain the most uniform distribution possible. The cement was placed in a cylindrical metal mold (4mmX6mm) covered on both sides with metal slides, clamped, and left in an incubator (at 37°C) for 1h to allow setting. Following setting, the samples were stored at room temperature in physiological saline for 24 hours and 1 week. The fractured samples were mounted onto aluminum stubs covered with conductive carbon tape and the morphology of the fractured surfaces was analyzed uncoated in high vacuum by SEM (Quanta™250 SEM ; FEI™Company, Oregon, USA) at 1.000× and 5.000×magnifications. Factors such as the integrity of the interface between the glass particles and the polymer matrix, the particle size, and the number and size of voids have important roles in determining the mechanical properties3. The results (Figure 2-5) indicate that the nanoparticles readily dispersed into the cement matrix and reduced the porosity of set cements by filling the empty spaces between the glass particles. Fewer air voids were observed in all nanoparticle containing cements and this reduced the development of cracks within the cement matrix.

Izvorni jezik
Engleski

Znanstvena područja
Dentalna medicina

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