Sorption of nanofilled versus other conventional composites

Since composite water sorption can result in expansion of the restoration,which would be detrimental to the restoration,it is important to limit the amount of water absorbed. the aim of this study was to evaluate and compare water sorption values of various composite materials. seven commercial light-activated composite materials: tetric evo ceram (ivoclar,vivadent,schaan/liechtenstein,austria),premise (kerr,orange,ca usa),herculite (kerr),z100 (3m-espe,st. paul,mn,usa),z250 (3m-espe),p60 (3m-espe) and supremext (3m-espe). ten disc specimens were prepared for each composite material using a stainless steel mold with 15 mm in inner diameter and 1 mm in thickness. the curing of each composite specimen was divided into 5 segments and each segment was photo-cures for 40 seconds. water sorption of different materials was calculated by means of weighting the samples before and after water immersion (15 days) and desiccation. data were analyzed by one-way anova at 5% level of significance. tetric evo ceram composite showed the lowest water sorption values followed by herculite,p60,supreme xt,z100,z250 and premise which exhibited the highest values. all the composites being tested in this study exhibited sorption values within the acceptable limits and composite composition significantly influenced its water sorption value.