School of Engineering and Materials Science
Research Student Roll of Honours
PhD Thesis: Glass Ioner cements: Investigations into secondary setting mechanism and kinetics of fluoride release.
Author: SHAHID, Saroash
Supervisor(s): Robert R Hill
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 fluoro-aluminiosilicate 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 GICís Fuji IX and Ketac Molar were used, along with commercial GICís 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. Ultrasound released the release of fluoride whereas radiant heat reduced the release of fluoride.
Investigation into secondary setting mechanism of glass ionomer cement: hydrolytic stability of aluminiosillicate-acetic 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 than immersed in 40ml of deionised water. After 24hours they were assessed for visual disintegration. 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-polyalkeonate cements hence suggesting that acetate cements are actually A1-acetate type cements.