Master thesis defence by Casper Madsen – Niels Bohr Institute - University of Copenhagen

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Master thesis defence by Casper Madsen

Improving glass ionomer cements through hydroxyapatite substitution: The influence of particle size and concentration

Glass ionomer cement (GIC) is used in dentistry as a restorative material due to its adhesion to tooth surfaces, good biocompatibility and its ability to release fluoride. However the mechanical properties make it undesirable for use in load bearing areas, such as large cavities in the molar region. Therefore the aim of this work was to modify a commercial GIC (Voco Ionofil Molar AC) hoping to improve the mechanical and physical properties of this material. The idea was to substitute part of the glass particles with hydrox-yapatite of different particle sizes using different concentrations. The testing methods used to evaluate the properties of the experimental materials were Compressive Fracture Strength (CFS), Thermogravimetric analysis (TGA) and X-ray Tomography. The results from the CFS tests seem to indicate that a 1wt% substitution is the most desirable. Moreover particle size appears to influence the strength. The results also seem to indicate that the hydroxyapatite-modified GIC reaches early strength faster than the commercial GIC."