Glass ionomer cements: an investigation into ionic processes within the cement with respect to time

A series of experiments were performed to understand the ionic processes in glass ionomer cements. Fluoride release from fluoroaluminosilicate glasses in deionised water and artificial saliva Inorganic artificial saliva was used to compare the release of fluoride from four fluoroaluminosilicate glasses (AH2. LG26Sr, LG125 and LG26). The glasses were used in their raw form and as an acid washed glass and pseudocement. Results showed two different trends. AH2 released more fluoride in artificial saliva relative to deionised water and the LG glasses released less in artificial saliva relative to deionised water. Kinetics of fluoride release from glass ionomer cements: influence of ultrasound and radiant heat Two conventional GIC’s Fuji IX and Ketac Molar were used, along with commercial GIC’s Amalgomer, Amalgomer CR and Glass Carbomer which was also radiant heat set. The experimental glass used was LG30 which is a fluoride free glass and was mixed at 7:1 ratio with 2% NaF solution. It was observed that ultrasound increases the release of fluoride whereas radiant heat reduces the release of fluoride. Investigation into secondary setting mechanism of glass ionomer cement: hydrolytic stability of aluminiosilicate-acetic acid cements Six glasses were used LG26, LG30, LG117, Anorthite, Na-Anorthite. Glasses were mixed with acetic acid and made into discs. These were matured for 1, 2, 3, 6 and 24 hours then immersed in 40ml of deionised water. After 24hours they were assessed for visual disintegration using a scale developed for this purpose. It was noted that MP4 never formed stable cement; LG26, LG117, Anorthite and Na-anorthite immediately formed a stable cement whereas LG30 formed a stable cement only after 24hours. Inductively Coupled Plasma analysis on the release of ions showed that Al was released in quantities comparable to glass-polyalkenoate cements hence suggesting that acetate cements are actually Al-acetate type cements. Declaration I declare that the material in this thesis is entirely my own work and that I have attributed any brief quotations, both at the appropriate point in the text and in the bibliography at the end of this piece of work, to their authors. I also declare, that I have not used extensive quotations or close paraphrasing and that I have neither copied work from another person, nor used the ideas of another person without proper acknowledgement. Name: Saroash Shahid Course: PhD Title of Work Submitted: Glass Ionomer Cements: An Investigation into Ionic Processes within the Cement With Respect To Time. Examination: A thesis submitted for the degree of Doctor of Philosophy, University of London.