Glass ionomer was mixed with water alone and with water containing two leve
ls of potassium ion, added as potassium chloride. The dimensions of the spe
cimens varied; discs, cylinders and a rectangular bar were used. Release of
potassium was measured until it ceased. A little potassium was released fr
om cement mixed with water but could be accounted for by traces present in
the glass. Release took 2 months for the lower level and 1.5 years for the
higher level of addition. For some specimen groups not all the potassium ad
ded was subsequently released. Potassium release tended towards the pattern
found for fluoride release naturally occurring from glass ionomer cements
in being proportional to t(1/2) but was less certain at the lower addition.
Release was not related to the dimensions of the sample as has been shown
for release of intrinsic fluoride. (C) 2001 Elsevier Science Ltd. All right
s reserved.