EFFECTS OF UNCONTROLLED OUTDOOR STORAGE ON THE POLYMERIZATION, MANIPULATION, AND APPEARANCE OF VISIBLE-LIGHT-CURED COMPOSITE RESIN AND RESIN-MODIFIED GLASS-IONOMER MATERIALS

Four light-cured composite resins (Z100, Heliomolar RO, Herculite XRV, and Prisma APH) and two resin-modified glass ionomer restorative mate rials (Fuji II LC and VariGlas VLC) were placed in an uncooled, unheat ed outdoor storage shed for 12 months, Maximum and minimum ambient tem peratures were recorded every 24 hours, Each month, samples were polym erized with a visible light source and alterations in polymerization w ere assessed using a scratch test. Problems with manipulation or chang es in appearance were also monitored, Samples stored outdoors were com pared to control samples maintained at room temperature [68-74 degrees F (20-23.3 degrees C)], Results showed that polymerization of all mat erials tested was apparently unaffected to any significant clinical de gree by outdoor storage at temperatures ranging from 20 to 112 degrees F (-6.6-44.4 degrees C) over 12 months, Eight months into the study, the VariGlas VLC liquid had separated into a viscous gel and watery co mponent, None of the other remaining materials demonstrated any change s in manipulation or appearance, All materials tested except VariGlas VLC appear suitable for use during military deployment or field traini ng exercises under similar environmental conditions.