effect of resin coating and chlorhexidine on microleakage of two resin cements after storage

objective: evaluating the effect of resin coating and chlorhexidine on microleakage of two resin cements after water storage. materials and methods: standardized class v cavities were prepared on facial and lingual surfaces of one hundred twenty intact human molars with gingival margins placed 1 mm below the cemento-enamel junction. indirect composite inlays were fabricated and the specimens were randomly assigned into 6 groups. in groups 1 to 4, inlays were cemented with panavia f2.0 cement. g1: according to the manufacturer's instruction. g2: with light cured resin on the ed primer. g3: chlorhexidine application before priming. g4: with chlorhexidine application before priming and light cured resin on primer. g5: inlays were cemented with nexus 2 resin cement. g6: chlorhexidine application after etching. each group was divided into two subgroups based on the 24-hour and 6-month water storage time. after preparation for microleakage test, the teeth were sectioned and evaluated at both margins under a 20× stereomicroscope. dye penetration was scored using 0-3 criteria. the data was analyzed using kruskal-wallis and complementary dunn tests. results: there was significantly less leakage in g2 and g4 than the panavia f2.0 control group at gingival margins after 6 months (p<0.05). there was no significant differences in leakage between g1 and g3 at both margins after 24 hours and 6 months storage. after 6 months, g6 revealed significantly less leakage than g5 at gingival margins (p=0.033). in general, gingival margins showed more leakage than occlusal margins. conclusion: additionally, resin coating in self-etch (panavia f2.0) and chlorhexidine application in etch-rinse (nexus) resin cement reduced microleakage at gingival margins after storage.