Objective: This study evaluated the microtensile bond strength (μTBS) of ion-releasing restorative materials to sound and caries-affected dentin (CAD). Study design: 60 teeth were randomly divided into 2 groups (sound dentin, CAD) and 5 subgroups of 6 samples each: conventional glass ionomer cement (GIC), resin-modified GIC (RMGIC), glass hybrid reinforced GIC (EQ), giomer (BII), and bioactive restorative material (ACT). μTBS analyses were performed and data were analyzed statistically. Results: The ACT group bonded to sound dentin and the BII group bonded to CAD showed the highest μTBS (p<0.05). The GIC, RMGIC, and ACT groups, showed significantly lower μTBS when bonded to CAD compared with sound dentin (p<0.05). However, in the BII group, there were no statistically significant differences between the samples bonded to sound and CAD (p>0.05). All groups except EQ that bonded to sound dentin showed predominantly adhesive failure. Conclusion: The use of the giomer can be recommended due to its more stable bond durability.