Water sorption, solubility, and resultant change in strength among three resin‐based dental composites

Abstract

OBJECTIVE: To determine the water sorption, solubility, and resultant change in strength of one microhybrid and two nanofilled resin-based composites (RBCs). METHODS: Water sorption, solubility, and three-point bending strength (TPBS) characteristics of a microhybrid RBC Filtek(™) Z250 (Z250; batch 8MA; shade A3) and two nanofilled RBCs, namely Filtek(™) Supreme XT "body" (FSB; batch 8NU; shade A3) and "translucent" shades (FST; batch 6C; shade YT) (3M ESPE Dental Products, St Paul, MN, USA) were investigated following 1 and 13 weeks storage regimes. RESULTS: FSB displayed a significant increase in water sorption compared with Z250 and FST (P < 0.001), however, the latter demonstrated no significant difference between them following 1 week and 13 weeks immersion periods (P > 0.001). Following the 13-week immersion period, FSB showed greater water solubility compared with Z250 and FST (P < 0.001). FSB exhibited greater TPBS compared with FST in dry control specimens (P < 0.05), but no significant difference among TPBS of all RBCs was identified following the 1-week immersion period (P = 0.290). The TPBS of FSB decreased significantly compared with Z250 and FST following the 13-week immersion period (P < 0.001). CONCLUSION: Since the FSB exhibited greater water sorption, solubility, and resulting strength degradation compared with Z250 and FST, a poor clinical performance may be expected.