IADR Abstract Archives
Acid-Erosion of Water-Based Luting Cements
Methods: The acid-erosion depths were measured per ISO-9917-1 following McCabe’s methodology that calls for 24h cure at 37C/95%RH before immersion in 37C 0.1M lactic acid/sodium lactate solution for 24 hrs acidic medium. In an attempt to separate the expansion effects from those of erosion, cements were also cured at 37C/95%RH for 2h and immersed in 37C water before being transferred to acidic solution. For water-expansion measurements, cements were cured at 37C/95%RH for 24h prior to immersion in 37C water. Five specimens of each category were made and the changes were monitored over a three-day immersion period. The depths/protrusions were measured using Mitutoyo profiler.
Results:
Mean values including standard deviations are summarized below:
Luting Cement |
Type |
Acid-Erosion Depth (1-day), mm |
Acid-Erosion Rate, mm/day |
RLP |
Resin-Modified GI |
0.008(0.001) |
0.00 |
FI |
Conventional GI |
0.133(0.004) |
0.12 |
HARV |
zinc phosphate |
0.220(0.016) |
0.16 |
HOFF |
zinc phosphate |
0.224(0.005) |
0.17 |
Conclusions:
ANOVA analysis was performed at p < 0.05 per Tukey’s test. The RMGI cement (RLP) showed significantly lower acid erosion depth compared to other cements (conventional GI and zinc phosphate) with and without accounting for water expansion. While FI, HARV and HOFF showed sustained rate of erosion with time, RLP exhibited no such erosion.