Erosion of a glass ionomer cement in acetic (AA), lactic (LA), citric (CA) and hydrochloric acids (HA) was investigated by means of chemical analysis, SEM observation and infrared (IR) spectroscopy. The larger stability constants of the complex between the acid anions and Al or Ca, or the lower the pH of the acid solutions, the more Al, Ca, Na, Si and F were leached. SEM observation revealed that the cement matrix dissolved out in 0.01M CA and HA. White precipitates formed in 0.01M CA and HA after immersion of the cement. They were identified as hydrated silicious gels by IR spectroscopy

No abstract

No abstract

No abstract

The amounts of Zn and Mg eluted from the zinc polycarboxylate cement into acetic, lactic and citric acids increased with an increase in the formation constant of the acid-Zn or -Mg complexes. The erosion process consisted of two processes, namely, dissolution of the unreacted cement powder and decomposition of the matrix.The matrix was remarkably eroded by 0.01M citric acid which formed stable complexes with Zn and Mg. Erosion of the matrix took place with the exchange reaction between H+ ion in the acid and Zn2+ or Mg2+ in the matrix.