Glass Poly-Vinyl-Phosphonate Cements with Reactive Aluminium Hydroxide Coated Sub-micron Anatase Filler
Brookbank, Paul A.
Thesis or dissertation
University of Exeter
This thesis has been supplied on condition that anyone who consults it is understood to recognise that its copyright rests with its author and that no quotation from the thesis and no information derived from it may be published without proper acknowledgment. © Paul Alexander Brookbank
Reason for embargo
Do not want data entering the public domain before the opportunity to publish in peer reviewed journals
The current generation of Glass Ionomer Cements (GICs) have many advantageous properties over other dental restorative materials but lack the compressive strength of these other materials. The aim of this project is to increase the compressive strength of conventional Glass Poly-Vinyl-Phosphonate cement by inclusion of reactive sub-micron filler particles. The setting characteristics, chemical reactivity and cement strength have been found using oscillating rheology, infrared spectrometry, nuclear magnetic spectrometry, transmission electron microscopy, potentiometer analysis, laser diffractometry and mechanical analysis. The addition of sub-micron filler particles in direct weight by weight replacement of aluminosilicate glass of a control material has increased the ultimate compressive strength of the new cement from 206MPa (control) to 250MPa after 365 days of aging. The strength of the new filler enhanced cements were comparable with the control material after 3 hours. The setting chemistry of the filler enhanced cements follows the same order as the control cement but at a decelerated rate. Theoretical modelling found that a large volume of sub-micron filler could fit into interstitial spacing in formed cement however the alteration of the aluminosilicate glass to polyelectrolyte ratio has been found to drastically alter the cement setting time. The use of cubic and polyhedral shaped filler particles as supposed to spherical particles may increase the cement strength further as greater packing densities are achieved. The formulation of a Glass Ionomer Cement with increased compressive strength may find use as a posterior restorative or as a better material for restoration of lesions and cavity liners.
Kemdent (Associated Dental Limited)
Great Western Research (GWR)
PhD in Engineering