Oral cancer patients, receiving gamma radiation as primary or supplementary treatment, commonly have a variety of dental restorations including resin-containing glass ionomer cements. Any interactive effects between the incident therapeutic beam and such materials might be of clinical significance if properties of these materials are adversely affected. In this investigation the effects of gamma radiation at three therapeutic dosage levels on the diametral tensile strength (DTS) and microhardness of three photo-cured glass ionomer restorative cements were determined. It was also the objective of this study to characterize the materials before and after gamma radiation using infrared spectroscopy. The results showed a significant increase in DTS of all investigated materials upon exposure to gamma radiation, Microhard­ness results for all materials showed, in general, an increase after irradiation. These findings were attributed to an increase in the degree of polymerization of these resin-containing photopolymerizable restorative cements. Infrared analysis of the three materials showed no change in their molecular structure (resin component) as a result of irradiation.

Saudi Dental Journal 1997;9(3):120-124.