comparison of microleakage and thickness of resin cement in ceramic inlays with various temperatures

background and aims. microleakage is still one of the major problems of composite-based restorations. this study compared the microleakage and thickness of resin cement in ceramic inlays with various temperatures. materials and methods. class v cavities were prepared on the buccal and lingual aspects of thirty human molars with occlusal margins in enamel and gingival margins in dentin (3 mm wide, 5 mm long and 2 mm deep). laboratory-made inlays (lmi) were used for buccal cavities, and cad/cam inlays (cmi) were used for lingual cavities. all the cavities were divided into six groups (n=10): 1) lmi at -5°c; 2) lmi at 50°c; 3) lmi at room temperature (25°c); 4) cmi at -5°c; 5) cmi at 50°c; 6) cmi at room temperature (25°c). inlays were bonded to cavities in a pulp pressure- and temperature-simulating device. after thermocycling and dye penetration, the teeth were divided into two mesiodistal halves. amount of dye penetration and film thickness were measured under a stereomicroscope and analyzed with kruskal-wallis, wilcoxon and spearman's correlation tests (ɑ = 0.05). results. there were no statistically significant differences in leakage between different inlay temperatures (p > 0.05). the mean cement thickness in laboratory-made inlays (gingival margin, 83.7 ± 11 and occlusal margin, 84.7 ± 19) was greater than that in cad/cam inlays (gingival margin, 69 ± 16 and occlusal margin, 84.7 ± 16). no correlation was found between cement thickness and microleakage either in enamel or dentin for any of the ceramic systems. conclusion. differences in inlay temperature had no effect on microleakage. cad/cam inlays had lower cement thickness than laboratory-made inlays, but this was not related to their microleakage.