PROPERTIES OF COMPOSITE RESIN ALKASIT AND ZIRCONIA-REINFORCED GLASS-IONOMER CEMENT IN DIFFERENT STORAGE

Background: The temperature and salivary pH in a person's mouth are highly
dynamic (e.g., before, during, and after eating) and so restorations in a cavity
must be resilient to these variable conditions. Temperature and immersion
conditions affect the mechanical properties of a restoration. This study aimed
to determine the effect of environmental conditions on diametral tensile strength
(DTS) and surface microhardness of a resin composite with alkaline fillers or
zirconia–reinforced glass ionomer cement (Zr-reinforced GIC).
Method: Thirty specimens of a resin composite with alkaline fillers (Cention-N,
Ivoclar-Vivadent, Lichtenstein) and 30 specimens with zirconia-reinforced GIC
(Zirconomer, Shofu, Japan) were stored at different conditions (23°C and 37°C;
with and without immersion in water) for 24 hours. DTS was tested with a
Universal Testing Machine (AGS-X series, Shimadzu, Japan) and surface
microhardness was tested with a Vickers Microhardness tester (HMV-G Series
Micro Vickers Microhardness Tester, Shimadzu, Japan). Data were analyzed
statistically using a one-way ANOVA test (and Shapiro-Wilk test.
Result: The values of microhardness and DTS increased significantly both for
the composite resin alkasite and zirconia-reinforced GIC with increasing
temperature in the groups without immersion. However, there was a significant
decrease in microhardness and DTS after immersion in distilled water at 37°C
for both the composite resin alkasite and zirconia-reinforced GIC.
Conclusion: It can be concluded that storage conditions affect the
microhardness and DTS of resin composite Alkasite and Zirconia-reinforced
GIC