Materials and methods. The roofs of pulp chambers and roots (1–2 mm below furcation) of 40 human first molar teeth were cut and pulp tissues completely removed. The teeth were randomly divided into two main groups (n = 20). Group E (experimental) was irrigated with 5% NaOCl and group C (control) was left untreated. For the experimental group, after obturation of root canals with gutta-percha and sealing the cavity with Cavit, the specimens were stored in artificial saliva for two weeks. Then each group was divided into two subgroups according to the total-etch or self-etch adhesive application protocol: Scotchbond Multi-Purpose and Clearfil SE Bond. The specimens were restored with composite resin using each bonding agent: Z250 and Clearfil Photo Core, respectively. Fluid filtration method was used for evaluation of microleakage. Data was analyzed using two-way ANOVA (α = 0.05). 

Results. Two types of dentin adhesive systems showed no statistically significant differences in microleakage (P = 0.77). NaOCl-treated groups demonstrated significantly higher microleakage values compared to the non-NaOCl-treated groups (P = 0.001). The interaction between the two factors was not significant (P = 0.78). 

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.