THE INTERACTION OF DENTAL GLASS-IONOMER CEMENTS WITH BUFFER SOLUTIONS

Abstract

Four brands of glass-ionomer cement (Fuji IX GP, Riva, Ketac Molar and Chemfil Superior) have been stored in aqueous media comprising distilled water, or phosphate buffer solutions at pH 5.42, 6.91 and 8.13 at 37°C for 7 days. Cements differed widely in their response. All took up small amounts of water in distilled water, and had high compressive strengths. Ketac Molar showed no differences in any of the buffer solutions, but gained small amounts in mass, and showed high compressive strength in all storage media. Conversely Chemfil Superior was adversely affected by all three buffers, and Fuji IX and Riva were adversely affected by the buffers at pH 6.91 and 8.31. The reasons for these differences were not clear, but the fact that the buffer closest to neutral (pH 6.91) caused significant damage to three of the cements studied shows that this is not a simple effect of pH.

Keywords

• glass-ionomer cements
• buffer solutions
• mass gain
• compressive strength