"The effect of sulfur on glass structure and the conversion process of bioactive CaO-LI2O-B2O3 glasses were studied. One glass without and two glasses with different amounts of sulfur were made using conventional melting and dry quenching techniques. These glasses reacted with a phosphate solution and converted to hydroxyapatite. Particles (150-355µm) were reacted in 0.25 and 0.5 molar K2HPO4 solutions at 37⁰C for 2 to 96 hours. The weight loss of the particles and the final pH of the solution were measured. The weight loss measurements indicated that the reaction rate increases with increasing the sulfur content. Sulfur was released from the glass, causing the pH of the solution to decrease, but was absent in the reacted layer.
In the in-vivo studies, the effect of sulfur and phosphorus on the conversion of two different bioactive borate glasses was studied, in-vivo. Discs made from two sulfur-free glasses (CaLB-0 and 93B3-0) and two sulfur-containing glasses (CaLB-12 and 93B3-6) were implanted in a subcutaneous site in rats for 2, 4, and 12 weeks. Each rat remained healthy during the experiment and there were no sign of infection or necrosis at the implantation site.
The CaLB glass discs reacted with the body fluids and formed a thin calcium phosphate reacted layer on their surface, but the 93B3 glass discs reacted to form a thicker calcium phosphate reacted layer with an onion-skin structure. Compared the phosphorus-free CaLB implants to phosphorus-containing 93B3 implants the CaLB implants absorbed 2 times more phosphorus from the body fluids to form the calcium phosphate reacted layer.
Compared to the CaLB implants, the connective tissue attached to the 93B3 implants was ~3 times thicker, and contained more blood vessels and collagen. For all of the sulfur-containing implants sulfur released to the body fluids and was not presented in the reacted materials"--Abstract, page iv.
Day, D. E.
Brow, Richard K.
Rahaman, M. N., 1950-
Brown, Roger F.
Materials Science and Engineering
M.S. in Materials Science and Engineering
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- The effect of sulfur on structure and conversion of bioactive borate glasses. Part I: In-vitro studies
- The effect of sulfur on structure and conversion of bioactive borate glasses. Part II: In-vivo studies
xiv, 114 pages
© 2012 Ali Mohammadkhah, All rights reserved.
Thesis - Open Access
Library of Congress Subject Headings
Glass in medicine
Print OCLC #
Electronic OCLC #
Link to Catalog Recordhttp://laurel.lso.missouri.edu/record=b11016866~S5
Mohammadkhah, Ali, "The effect of sulfur on structure and conversion of bioactive borate glasses" (2012). Masters Theses. 7444.