The Influence of Dry and Wet Conditions on Filling Materials

Objectives: The aim of this study was to evaluate the influence of dry and wet conditions on the flexural strength of filling materials.
Methods: We used three different filling materials: composite resin (CLEARFIL MAJESTY ES Flow Low type, Kuraray Noritake Dental Inc, Tokyo, Japan), resin-modified glass-ionomers (FUJI II LC CAPSULE, GC Corporation, Tokyo, Japan) and conventional glass-ionomer cements (FUJI IX CAPSULE, GC Corporation, Tokyo, Japan). The flexural strengths of filling materials were measured by a three-point bending test. We performed three-point bending test under three different conditions: (1) 24 hours (control group), (2) in distilled water at 37°C for 6 months, (3) in dry condition at 37°C for 6 months, after sample preparation. The data were analyzed by one-way analyses of variance and Tukey’s multiple comparison test (p<0.05).Moreover, we observed sample surface by stereoscopic microscope.
Results: The bending strength after 24 hours was higher in order of ES Flow, FUJI II LC CAPSULE, FUJI IX CAPSULE. After 6 months storage in water, the bending strength of all materials decreased compared with control. After 6 months in dry condition, the bending strength of ES Flow and FUJI IX CAPSULE did not decrease significantly, however that of FUJI II LC CAPSULE increased compared with control. Sample surface of FUJI II LC CAPSULE and FUJI IX CAPSULE in dry condition were observed microscopic cracks.
Conclusions: Water storage for 6 months decreased the bending strength of all materials. Dry condition for 6 months had different influence for each material.