DERANGEMENT OF COMPOSITE FILLER DISTRIBUTION INSIDE SYRINGE-TYPE DELIVERY SYSTEMS

Used and almost emptied syringes of two brands of composites contained material close to the pestle-head that appeared to be more granular a nd dry, as compared to the composite obtained from unused syringes. Th e present results suggest that a derangement of filler and matrix phas es occurred inside the used syringes when compared to unused controls. Stress imposed on the composite material inside the unused syringes r esulted in a comparable derangement of filler and matrix phases. Altho ugh this derangement was limited, the effect could contribute to intra - and interlaboratory scattering of data.