Jw. Nicholson et al., THE INCORPORATION OF HYDROXYAPATITE INTO GLASS-POLYALKENOATE (GLASS-IONOMER) CEMENTS - A PRELIMINARY-STUDY, Journal of materials science. Materials in medicine, 4(4), 1993, pp. 418-421
Citations number
23
Categorie Soggetti
Material Science","Polymer Sciences","Medicine Miscellaneus
The effect of adding finely divided hydroxyapatite (HAp) powder to gla
ss-polyalkenoate cements has been studied. Two different glasses were
used in cement formation, an oxide and a fluoride glass. Cements were
prepared at a powder: liquid ratio of 2:1, higher ratios being unattai
nable because of the low bulk density (hence large volume fraction per
unit mass) of HAp powder. For the oxide glass there was a steady redu
ction in compressive strength and an increase in working and setting t
imes with increased loadings of HAp. By contrast, for the fluoride gla
ss, there was a plateau region from 2.5 to 40% by mass HAp in the glas
s powder in which the compressive strengths and the working and settin
g times remained approximately constant. At HAp levels above 40%, as f
or the oxide glass, there was a significant reduction in strength and
an increase in working and setting times. The presence of HAp in the c
ement was not found to inhibit the development of compressive strength
with time for cements prepared from the fluoride-containing glass. Ce
ments prepared from the oxide glass, by contrast, did not increase in
strength with time and this feature was also not changed by the presen
ce of HAp.