microleakage of class v compomer and light-cured glass-ionomer restorations under load cycling: an in vitro investigation

statement of the problem : tooth restorations are exposed to stresses which produce marginal gaps resulting in microleakage. purpose in this study, microleakage of light-cured glass-ionomer and compomer class v restorations was evaluted and compared under cyclic loading materials and methods in this exprimental study, class v cavities were prepared on the buccal surfaces of maxillary premolars (n=40). the teeth were randomly divided into two equal groups. samples in one group were restored with compoglass and those in the other group were restored with fuji ii lc. all the samples were thermocycled for 2500 cycles. each group was subjected to cyclic loading (10000 cycles). dye peneteration method was used for samples. finally, microleakage of the restorations was evaluated under a stereomicroscope at ×20. data were analyzed with chi-squared test. the confidance level was set at 95% (α=5%). results : microleakage was observed at 55% of restoration margins with both materials, with more leakage in the compoglass group. the results showed no statically significant differences between the two groups (p>0.05). in addition, no significant differences were seen in microleakage between gingival and occlusal margins (p=0.64 and p=0.7, respectively). conclusion microleakage of compoglass and fuji ii lc restorations was not different at margins under cyclic loading