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Full-Text Articles in Biomedical Devices and Instrumentation
Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill
Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill
Chemical and Biochemical Engineering Faculty Research & Creative Works
Fuji IX glass is a low phosphate, low soda containing glass which has strontia incorporated as a radio-pacifier. This glass material was analyzed during exposure to different durations of ultrasound in an attempt to determine how the glass phase reacts. Cross sections of Fuji IX cement, set both conventionally and by ultrasound, were subsequently compared by microscopy. The resultant data were analyzed in detail.
Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo
Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo
Chemical and Biochemical Engineering Faculty Research & Creative Works
Glass ionomer cements (GICs) are an important class of biomedical material used extensively for color matched mercury free, dental restorations. GICs can release clinically beneficial amounts of fluoride and have acceptable handling properties which make them suitable as dental restoratives. The fluoride release of model GICs produced from specially synthesized fluoro-alumino-silicate glasses was studied. Nine glasses of varying fluoride content based on 4.5SiO2-3Al2O3-1.5P2O5-(5-Z)CaO-ZCaF2 were synthesized, and cement disks were prepared from them. The glass transition temperature reduced with increasing fluorine content of the glass. Fluoride ion release was measured …
A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan
A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan
Chemical and Biochemical Engineering Faculty Research & Creative Works
No abstract provided.
Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol
Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol
Chemical and Biochemical Engineering Faculty Research & Creative Works
Fly ashes exist as a mixture of major amorphous phases and minor crystalline phases. For commercial applications, such as in concretes and for the production of zeolites, it would be desirable to be able to predict the reactivity of fly ashes. The amorphous phase dominates degradation behaviour, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. Despite the large quantities of fly ash produced annually by coal-burning power plants, there have been very few studies investigating the microstructure and composition of …
Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol
Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol
Chemical and Biochemical Engineering Faculty Research & Creative Works
The amorphous phase of fly ash dominates degradation behaviour because glass has a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. It would be advantageous to predict the presence and subsequent degradability of glass on the basis of the solid-state chemistry of the fly ash. To this end, and inorganic polymer model was applied to a selection of European fly ashes to determine the value known as cross-link density (CLD). A cross-link density value of less than two implies that the material is amorphous …
The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson
The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson
Chemical and Biochemical Engineering Faculty Research & Creative Works
The effect of low levels of zirconia addition on the mechanical properties of hydroxyapatite was analyzed. Optimum amount of zirconia required to prevent decomposition of hydroxyapatite during sintering was determined. The particle size, morphology and surface area were measured and calcium to phosphorus ratio and trace element impurity content were determined by x-ray fluorescence. Low level addition of zirconia resulted in composites with better mechanical properties and minimum levels of decomposition.
The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood
The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood
Chemical and Biochemical Engineering Faculty Research & Creative Works
A study of glasses from the ternary system CaF2-CaAl2Si2O8-P2O5 has been carried out. It has been shown that glasses with low phosphorus contents and high fluorite contents crystallise to fluorite. Fluorine reduces the glass transition temperature and is also required for the formation of fluorapatite (FAP). In the absence of fluorine in the glass no apatite phase is formed. Bulk nucleation of FAP is favoured for glasses with Ca:P ratios close to the apatite stoichiometry of 1.67 and with low crosslink densities. Thermal gravimetric analysis showed significant weight losses …
A Preliminary Comparison Of The Mechanical Properties Of Chemically Cured And Ultrasonically Cured Glass Ionomer Cements, Using Nano-Indentation Techniques, Mark R. Towler, A. J. Bushby, R. W. Billington, R. G. Hill
A Preliminary Comparison Of The Mechanical Properties Of Chemically Cured And Ultrasonically Cured Glass Ionomer Cements, Using Nano-Indentation Techniques, Mark R. Towler, A. J. Bushby, R. W. Billington, R. G. Hill
Chemical and Biochemical Engineering Faculty Research & Creative Works
There is a requirement for a dental cement with properties comparable or superior to conventional glass ionomer cements (GICs) but with the command set properties of the resin modified GICs. The objective of this work was to show that the application of ultrasound to conventional Fuji IX commercial glass ionomer cement imparts a command set, whilst improving the short-term surface mechanical properties. Nano-indentation techniques were employed to highlight the improvements in hardness and creep resistance imparted to the cement through the application of ultrasound. The instant set imparted by the application of ultrasound provides improved surface hardness and creep, particularly …
Novel Processing Of Hydroxyapatite-Zirconia Composites Using Nano-Sized Particles, Mark R. Towler, I. R. Gibson, S. M. Best
Novel Processing Of Hydroxyapatite-Zirconia Composites Using Nano-Sized Particles, Mark R. Towler, I. R. Gibson, S. M. Best
Chemical and Biochemical Engineering Faculty Research & Creative Works
A method to produce composites of hydroxyapatite (HA) with ZrO2 (Y-TZP) additions between 0 and 10 wt % at a low sinter temperature of 750 °C is presented. The method limits the amount of reaction between the HA and ZrO2. A ZrO2 loading level that would improve strength while limiting the decomposition of the HA is studied.
Effects Of Adding Sodium And Fluoride Ions To Glass Ionomer On Its Interactions With Sodium Fluoride Solution, R. W. Billington, P. C. Hadley, Mark R. Towler, G. J. Pearson, J. A. Williams
Effects Of Adding Sodium And Fluoride Ions To Glass Ionomer On Its Interactions With Sodium Fluoride Solution, R. W. Billington, P. C. Hadley, Mark R. Towler, G. J. Pearson, J. A. Williams
Chemical and Biochemical Engineering Faculty Research & Creative Works
This investigates the effects of the addition of Na and F ions to a glass ionomer cement in which those ions are not inherently present on its interactions with dilute (0.2%) NaF solution. Both the effect of the solution on the cement's surface morphology and the effect of the cement on the solution in terms of take up of Na+ and F- and of change in pH are to be investigated. These results are to be compared to previous results obtained with glasses which contained both, one, or neither of the ions as components of their glasses. NaF …
The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler
The Influence Of Poly(Acrylic Acid) Molar Mass On The Properties Of Polyalkenoate Cements Formed From Zinc Oxide/Apatite Mixtures, Sinead Kenny, Robert G. Hill, Mark R. Towler
Chemical and Biochemical Engineering Faculty Research & Creative Works
The influence of poly (acrylic acid) molar mass was investigated on cements formed from zinc oxide-apatite mixtures at three aging times: one, seven and 28 days. Cements based on both hydroxyapatite and fluorapatite were investigated. The compressive strength, un-notched fracture strength and fracture toughness increased markedly with poly (acrylic acid) molar mass. The fracture toughness and un-notched fracture strength increased with aging time for the two highest molar mass cements but decreased with time for the two lowest molar mass cements. The greater chain entanglement density present in the higher molar mass cements is thought to contribute significantly to the …