Alternative interpretations of water sorption values of composite resins

Water sorption values for direct filling resins and an unfilled resin were much more similar at 30 days when expressed as mg/g organic matrix than as mg/cm2 or weight percent. This interpretation is indicative of the water sorption characteristics of resin matrices. The values are even more indicative when solubility or leaching is taken into consideration. With the specimen sizes used in this study, the effect of the kinetics of water sorption could be minimized by using values obtained after immersion in water for 30 days.