Journal of Applied Polymer Science, Vol.69, No.6, 1153-1158, 1998
Aging studies of a radiopaque light-cured dental composite in food-simulating liquids
Sorption behavior and changes in physical properties of an indigenously developed radiopaque light-cured dental composite upon aging in citrate buffer (pH : 4.0), 50% ethyl alcohol and saline for a total period of 80 days, have been studied. Water uptake into the composite reaches saturation within 14 days in all media, whereas solubility values show an upward trend even after storage for 80 days. Solubility in alcohol medium is found to be high compared to saline and citrate media. Compressive strength and diametral tensile strength measurements tend to increase initially and then decrease gradually with time due to degradation of the composite upon storage. However, this reduction Is not appreciable, as indicated by the strength values after 80 days, which are higher than the mandatory 220 MPa for CS and 34 MPa for DTS. Microhardness increases with time in all three cases, although alcohol medium tends to soften the material, resulting in an initial sharp decrease.
Keywords:DEGRADATION;FILLER