Particle sedimentation in a dental resin investigated by dielectric analysis (DEA) using IDEX-sensor

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70883521%3A28110%2F19%3A63524307" target="_blank" >RIV/70883521:28110/19:63524307 - isvavai.cz</a>

Alternative codes found

RIV/70883521:28610/19:63524307

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Particle sedimentation in a dental resin investigated by dielectric analysis (DEA) using IDEX-sensor

Original language description

Acrylic resins are the base of most light curing dental resin composites being highly particle filled to meet a manifold of requirements. Practically two aspects are important: 1st handling and flow behavior during cavity filling investigated by rheometer experiments, and 2nd curing behavior investigated by DEA in terms of ion viscosity during irradiation due to the fast reaction rate. IDEX-sensors are flat sensors with comb-like interdigitated electrodes whose grid field has a finite reach into the sample approximately given by the electrodes distance. This allows for measuring curing reactions depth dependently or sedimentation of suspensions to optimize the composites. As DEA measurements with IDEX-sensors are easy to perform the idea is to apply it for quality assurance purposes of particle filled suspensions to control filler contents. Therefore, dental resin composites with filler filler contents from 25 to more than 70wt% were investigated with respect to their initial ion viscosity. The initial ion viscosity is dominated by high ion mobilities in the liquid resin whereas the solid filler particles contribute only little to it. Assuming a homogeneous particle distribution, filler volume content changes affect apparently the mean ion concentration of the resin. Thus, for a resin with a given initial ion viscosity one can calculate the filler content dependent initial ion viscosities of suspension. However, the measured values exceeded systematically the predicted ones for filler contents below 50wt% what could be explained by sedimentation. Therefore, a measuring cell was designed allowing sample heights much larger than the reach of the fringe field. Starting with a homogeneous suspension, sedimentation can be observed as an increase of the ion viscosity until reaching a maximum value. Then, the measuring cell is turned upside down and the ion viscosity starts to decrease until a minimum value is reached. First results of sedimentation measurements are shown for diluted dental resin composites.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

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OECD FORD branch

20505 - Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics; filled composites)

Project

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Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2019

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů