Effect of Endodontic Irrigants on Microtensile Bond Strength To Dentin After Thermocycling and Long-Term Water Storage

Objective: the bond strength of adhesives in irrigated dentin behaves differently over time. the aim of this study was to evaluate the influence of long-term water storage and thermocycling on the microtensile bond strength of adhesive systems to dentin irrigated with endodontic solutions.materials and methods: sixty human molars were used after removal of the occlusal portion and exposure of the dentin by grinding. the specimens were irri-gated with 2.5% naocl for 30 minutes and then 17% edta for 5 minutes and assigned to six groups according to the adhesive system (n=10): g1 and g2–clearfil se bond; g3 and g4–single bond 2; and g5 and g6–xp bond. the teeth were restored with composite and were subjected to water storage for different time periods. g1, g3 and g5 were stored for 24 h; g2, g4 and g6 were stored for 6 months and were subjected to thermocycling (12,000 cycles, 5°c to 55°c, 500 cycles per week for 6 months). after storage, the tooth/restoration assembly was sectioned to obtain four sticks of approximately 1 mm^2, for microtensile bond strength testing. the results were analyzed by two-way anova and tukey’s test.results: significant differences were observed among the adhesives (p<0.01). no significant differences were observed in the microtensile bond strength between samples after 24 hours of storage without thermocycling and after 6-month sto-rage with 12,000 cycles (p<0.05).conclusion: the bond strengths of g5 and g6 after irrigation with 2.5% naocl and 17% edta were significantly different from those of other groupgroups. long-term water storage/thermocycling had no effect on bond strength to dentin.